| Adding auto crossfeed?
(Fri Aug 3, 2001) |
Crossfeed Nut (Jun 2, 2003) |
| Powered Cross Feed (Fri
Sep 21, 2001) |
Crossfeed nut replacement instructions (Jun 26, 2003) |
| Next Project Cross Feed Screw
(Fri Sep 21, 2001) |
Cross feed - compound rest slop (Jul 7, 2003) |
| New crossfeed dial (Oct
1, 2001) |
Crossfeed slop (Jul 24, 2003) |
| 10K cross feed bushing
(Oct 15, 2001) |
Cross feed and slide compound brass nuts (Sep 13, 2003) |
| Replacing cross-feed screw /
Heavy 10 (Oct 31, 2001) |
Successful crossfeed rehab (Nov 21, 2003) |
| Cross-feed screw replacement
(Jan 17, 2002) |
Inquiry for Crossfeed Screws
(Apr 12, 2004) |
| Cross Feed Nut (Jan 22,
2002) |
9" crossfeed nut (Jun 9,
2004) |
| Crossfeed screw (Jan 23,
2002) |
"Play" in crossfeed screw
(Nov 22, 2004) |
| Heavy 10 crossfeed acme
leadscrew dia (Apr 27, 2002) |
Cross Feed play (Nov 30,
2004) |
| Cross feed disengagement
(Dec 22, 2002) |
Price of Crossfeed screw?
(Dec 23, 2004) |
| Replacement cross feed nut
(Jan 26, 2003) |
Crossfeed slop measurement?
(Dec 24, 2004) |
| Crossfeed nut question
(Jan 30, 2003) |
Slop In Crossfeed and How To
Correct It (Jan 1, 2005) |
| Crossfeed nut-success
(Feb 6, 2003) |
Cross feed nut (Jan 5,
2005) |
|
Cross feed parts diagram (Apr 1, 2003) |
Cross Feed Screw Nut
(Jan 8, 2005) |
|
Cross Feed Screw (Apr 24, 2003) |
SB9 Power Cross Feed
(Jan 10, 2005) |
|
Model A power cross feed? (May 4, 2003) |
Worn crossfeed screw
(Jan 16, 2005) |
| Too
much play (May 31, 2003) |
Slop in crossfeed screw
(Mar 6, 2005) |
| |
| Adding auto crossfeed? |
| I have a 9" model
"C" without the auto cross feed option. If I buy a new apron which
has this feature are there any other modifications I need make other
that install the new apron? (1256) |
| Yes you will need the saddle and
cross feed lead screw as well. JWE (1257) |
| Actually, you would
only need the screw, as the saddle casting is the same. But that is
the easy part. There is a keyed worm gear in the apron that runs in
a keyway the length of the leadscrew that provides power for the
cross feed. The model C does not have this keyway in the leadscrew.
The two options here are get a leadscew off a model B (model A
screws would be too short due to the QC box), or cut a key in your
current screw. Actually there is a third option, find a QC box and
leadscrew and convert to a model A. As you may have guessed, that is
what I am in the midst of. I have wrangled all the parts but the
crossfeed screw (hmm... isn't that where we started?), and after
seeing what they are bringing on EBay I have decided to make my own.
Now I'm just waiting for access to my dads shaper to cut the "gear"
on the screw. Frank (1260) |
| Powered Cross Feed |
| I've got
a 9" model 'C'. It's a SB clone (Australian Hercus). Looks the same
as SB, apart from the drive. The Hercus comes in the same
configurations as the SB. The Hercus 'C' doesn't have a Q/C gearbox
or powered cross feed. The Hercus 'B' has the powered cross feed but
not the Q/C G/B. And of course the 'A' has all the above. I can live
without the Q/C gearbox (I've got a full set of gears). But I miss
the powered cross feed (mainly for smooth, end facing). My question
is can the cross feed be powered independently? I've had limited
success with cordless drill and a jury-rigged ball-crank attachment.
The trick is to keep the speed low enough and constant enough, to
give a good finish. Ideally a small DC geared motor fixed the
compound rest should give the results I want! Has anybody done this?
Is there an aftermarket solution to this? Or another way of tackling
the problem? Remember I'm in Australia! There is not the same volume
of machinery here. So, 2nd hand parts are few and far between,
especially 'A's and 'B's. Bill
(1578) |
| I think you have identified the best solution for this
problem. The 1967 Hardinge HLV-H I'm restoring uses a low speed DC
motor for precisely that purpose, both to eliminate gear tooth
vibration that occurs when you feed off of the high speed spindle
drive, and to allow infinite adjustment of feed rates "on the fly"
without changing the spindle speed or other gearing. I can't address
the fabrication difficulty since I don't have your particular lathe,
but the Hardinge uses a slow speed gear train in the apron to get
torque up to the crossfeed screw, which has a gear as a part of its
assembly. That doesn't sound very practical for your lathe. Perhaps
a drive off the rear of the crossfeed screw? The Hardinge drive
motor travels along with the carriage, so that part of the concept
is well proven. Mike
(1580) |
| I saw the other
post on the Hardinge lathe. Its a good setup, I don't know about the
feasibility of adaptation. Another solution might be one of the
single axis CNC retro fits. I think I saw a single axis setup for
$100. Tom (1581) |
| Some
months ago I opened a discussion about adding power feed to my model
'C' crossfeed. I've been experimenting with different ways of going
about it and have settled on an inexpensive and simple method that
really works. I toyed with the idea of feeding power to the back of
the crossfeed screw with a bracket mounted motor thru some form of
clutch. This turned out to be more trouble than it's worth. In the
mean time I picked up a couple motors from a local surplus dealer
that I thought would give about the required RPM (0-30 RPM). One was
a small 240V AC about 50mm (2") round. It probably would have done
the job. It had plenty of torque, but I balked at having a AC lead
around the moving parts of the lathe. The second motor I picked up
was a geared 24V DC motor. It looks like a windscreen wiper motor
and is probably off a truck, being 24V! The surplus dealer stated
that the motor would run down to 3V. I tested it with a car battery
and it spun at about 20 RPM on 12V. The motor body fits comfortably
in the palm of your hand and that's when I got the idea of using it
handheld on the crossfeed ball crank. I wiped up a plastic
prototype adaptor as a POC (Proof Of Concept) and was pleased with
the result. I then took some proper measurements and made a measured
drawing in CorelDraw 7. I then made the final adaptor in Al. I
remembered an old model train controller buried in one of my junk
boxes. I dug it out, attached the motor and tested it out. I can run
the crossfeed at between 2 and 20 RPM. I can now get a very smooth,
even surface when facing, that I could not achieve before! I have
uploaded some pics of the adaptor and a measured drawing along with
the CorelDraw file to the files DB at:
http://groups.yahoo.com/group/southbendlathe/files/Hercus%20%28Clone%29/Crossfeed%20Drive Bill (2519) |
| Maybe this would not work on a
Southbend, but I added power crossfeed to my old six inch Atlas. As
the computer mavins say, it was a Kludge, but it worked. I drilled
and tapped the tail stock end of the lead screw. Secured a flanged
drum about an inch or so in diameter there. Took the handle off the
crossfeed and replaced it with a similar drum (Added a scale to one
side of the drum). Put a pulley (small boat block) on the workbench.
To use this power crossfeed you wrap a cord around the cross feed
drum, through the pulley then to the drum on lead screw. Sure did
not look like a machine shop setup but worked well when facing large
jobs. Would have worked better if I could find that "frictionless
pulley" and "inextensionable infinitely flexible string" so beloved
by my first year physics instructor. John (2521) |
| Bill, Nicely
done. That's just the kind of adapter I was thinking of using with a
cordless drill-driver for use as a power compound feed. It's hard to
crank consistently when making short tapers using the compound. Your
use of a wiper motor is ideal since it uses worm gear reduction and
provides a much slower speed and good torque. The only down-side of
this type of solution is having to hold the motor during the
operation. Could a flex-shaft be used in this kind of application or
is the torque too high? Maybe make a clip-on adapter containing a
worm-gear reduction right at the ball-crank handle and power it
remotely via a flex-shaft. Maybe even a hybrid of yours and John
Meacham's ideas and take the power right from the lathe itself. Just
thinking out loud. Thanks for the pictures in the file area.
Paul R. (2527) |
| Paul, I tried a
flex-drive of sorts on the rear of the crossfeed screw. I tried
various types of plastic tubing until I found one stiff enough not
to twist too much and give a jerking motion when the kinetic energy
overcame the friction. The one I found worked great at almost 90o .
It was a high pressure hose with an I.D. of 10mm. I gave up on the
idea, though, because it was to difficult to disengage when I wanted
to use the crossfeed normally. A clutch system is needed to make
something like that work. Besides, holding the wiper motor is no
worse than trying to rotate the ball-crank smoothly and requires
less concentration on the ball-crank and allows more on the job
itself. Bill (2534) |
| Next Project
Cross Feed Screw |
| Changing out
the lead screw in my old South Bend 10" heavy made such a great
improvement that I'm going to tackle the cross feed screw next. Got
it apart last night 51 years of goo and gummed up oil but "Kroil"
did it again ,dissolved everything in less that 2 hours. My lathe
came fitted with the Telescoping taper attachment. Several balls in
the thrust bearings are missing and the Acme feed screw is badly
worn ( looks like a vee thread in the middle ). The nut is no
better. I'm going to attempt to sleeve the nut and replace the lead
screw with a piece of Acme 7/16"-10 single start threaded rod as
South Bend wants a small fortune for replacement parts. Anyone ever
try sleeving a cross feed nut ? Alas, anyone have a source of Acme
left hand threaded rod and matching bronze nut? Steve
(1586) |
| Try
McMaster-Carr, Enco, J L as well as some other suppliers. I replaced
the feed screws and nuts in a couple of our old mills at work this
way. The other option is buy a tap at about $35 from one of them and
turn the screw on your lathe. JWE(1587) |
| New crossfeed
dial |
| I have completed the new crossfeed dial and bushing I
mentioned earlier and have posted pics in the photos section for
your comments, questions, and what have you. Briefly, new part were
desired because of a previous owners accident and less than
acceptable repair. The new pieces are made of 416 stainless, (I had
it on hand) and the outside diameter is increased to 2.000", 1/4"
larger than the original. This provides more space between the
divisions making them easier to read. I also made them much finer
than the original. Besides the new dial and bushing, a new sleeve
was turned for the dial to ride on, and a new, longer brass "shoe"
was needed for locking the dial due to the larger OD. You will
notice that I decided to machine a hex on the bushing for tightening
purposes instead of the original spanner hole. No particular reason
for this, I guess it's just a personalization detail. Please
disregard the cardboard backing in the photos, I'm not trying to
hide anything, I just needed to force the camera to focus on the
intended subject better. So what do you think? Raymond (1666) |
| Ray, nice job! I
went up and looked at the photos. You did a good job on the photos
too. I would love to read the details of machining the divisions and
the numbers on the dial. Are those numbers stamped with a punch?
Chris (1667) |
| Very nice, Raymond!
Did you CNC the dial? It looks way too good to be done manually (esp.the
numbers). How easy is it to read the dial? Do you need to fill the
grooves with black enamel? All I can say is "I want one". Any
thoughts on making 'em for the group? Paul R. (1678) |
| Chris, Paul, and
others: (esp.the numbers). Whadda ya mean, "way too good"?! Is that
some kind of crack?! ;) I must admit, I did CNC the numbers and the
divisions. (Notice that there are lines of three different lengths!)
I used a Yuasa 5C CNC indexer that interfaced with a Matsuura RA-I
machining center at work. I made a special engraving tool from a 60
degree Ford uni-flute spotting drill, a plug fixture to hold the
part in the collet, wrote the programs for both the mill and the
indexer, set it up and ran it off. That is all I did CNC. Everything
else was performed at home on this lathe and my Bridgeport. I
clamped down tight on the crossfeed gib and used the compound set at
90 degrees while I had all this stuff apart. The radius on the face
of the dial was made simply by setting the tool and tool post
appropriately and swinging/advancing the compound with the carriage
locked. Very easy. I can actually "split" the divisions and go a
half a thou without having to squint. I hadn't thought about it too
much. It would probably make the dial even easier to read, but the
lines themselves are only about .004 deep. My personal experience
with doing this to similar items have not been very successful.
group? Gee, I dunno. Frankly, I'm flattered you ask. I'd be more
than happy to answer any more specific questions anyone may have,
but I'd have to put some thought into providing parts and/or
machining services to others, in the group or otherwise. I never
really considered it before. Hmm... maybe! Raymond (1686) |
| For anyone interested, I am working on AutoCAD drawings
of the crossfeed dial and bushing I made (see message #1666), and
will post them in some universal format such as .jpg in the files
section when they are complete. Raymond (1751) |
| Ray I can't
wait! This has moved to project #2 in a list of several billion,
besides I have to replace the crossfeed screw and nut soon so I
might as well do a proper job of it!! Pete (1755) |
| Excellent idea. If possible I'd like to have a copy of the
DWG file in AutoCAD R12 or R13 format (that way it's editable which
might be useful). As far as saving it as a pic file of some sort,
let me suggest GIF in preference to JPG. GIFs are substantially
smaller in byte count for line drawings (save in 16 color format)
and are at least semi-editable whereas any editing of JPGs quickly
runs into problems with loss of quality. Anthony (1759) |
| I'm
interested in this remark. Why not just 2 colors? (1760) |
| That's funny! Chris
(1762) |
| Actually, that
would be better *unless* he's differentiating elements with
different colors. For differentiation, 16 should be ample, for
simple black and white 2 color is superior. Anthony (1767) |
| Raymond, if you
could post the .dwg's too it would be greatly appreciated. Frank (1775) |
| 10K cross feed
bushing |
| I have added a new folder to the file section
containing drawings for the new bushing and graduated dial I made
for my 10K. Unfortunately for some, the drawings are AutoCAD R12 and
many of you may not be able to view them. For this I am sorry. I am
working on converting them to a more universal format (.jpeg, .gif,
.bmp) that doesn't take up a huge amount of space, and I will post
another message when I get it figured out. Raymond (1862) |
| Raymond: Thanks
very much for taking the time to post the drawings!! This is
something that I have been considering for a while and it is sure
easier now that I have some clear direction. I don't have AutoCAD
but I was able to open the drawings with turbocad 2D, which I
downloaded from the net free from this site.
http://www.turbocad.com/
(usual disclaimer) What is the Part # of the thrust bearing? I will
have to buy one as my machine has small dials.
Pete (1864) |
| Thanks for the
files Raymond, I prefer the .dwg files because I use ACAD all the
time. For those without ACAD try Volo View Express, it's Autodesks
free viewer, www.autodesk.com It kinda sorta
works about part of the time. Frank
(1868) |
| I am working on
converting them to a universal format (.jpeg, .gif, .bmp) that
doesn't take up a huge amount of space, and I will post another
message when I get it figured out. Folks: With a lot of help from
Anthony, I was able to get the drawings converted to .gif and I have
uploaded them to the folder. I hope there are no problems viewing
them. Raymond
(1881) |
| Thanks for your
interest in my little project. Unfortunately, I don't know the part
number for the thrust bearings I bought. I just called a local
bearing house (Eastern Bearing in Manchester, NH) and over the phone
described what I need to replace including id, od, and thickness,
and they were able to match it up. The South Bend part number from
my 10K parts manual is AS841R1. I would suggest going the local
route, factory parts can be rather expensive. Raymond
(1882) |
| Replacing
cross-feed screw / Heavy 10 |
| I purchased a
"newer" cross-feed screw assembly on Ebay. It includes the dial,
handle, brass nut, etc. Is there a trick to removing the old one?
Any tips? George (2038) |
| If you are pull'in and putt'in as an assembly, just remove the rear cover, the
little and big screws that secure the nut, and the little oil screw
just ahead of the dial bushing. I use a strap wrench on the dial
bushing because it is soft as cheese to a spanner wrench. R/h
thread. Joe (2041) |
| Cross-feed
screw replacement |
| And with any of
these lengths of threaded rod, can we assume that we can easily
machine the end as needed? They aren't hardened too much are they?
Am I remembering right. Didn't you (JWE) machine a replacement
cross-feed nut for your 9" SBL? I'm reminded of an MW article
("Tyro's First Lathe", Feb/Mar 2000) that describes the replacement
of the 7/16-10/LH cross-feed screw with a shop-made 1/2-10/LH ACME
lead-screw and re-tapping the original feed nut to 1/2-10. Is this a
good way to go? Are the proper left-handed taps readily available?
The best thing about machining your own nut is to add a backlash
adjustment to it. Your thoughts? Paul R. (2776) |
| That was the
7/16-20LH cross feed screw for the 9x20 you are thinking of. My SB
still has the factory screw and nut and I have not even looked at
them in years as there is only half a turn slack in it and for that
not worth adjusting it. JWE (2787) |
| Cross Feed Nut
|
| I don't think all
the cross feed nuts are 3/8 - 10 ACME, my Heavy 10 was I believe
7/16 - 10. B.G. (2870) |
| My 9A is
.430-something [very worn] OD by 10 TPI. (2879) |
| Crossfeed screw |
| With regards to the
crossfeed screw replacement issue, I have a couple of questions and
comments. 1) The screw on my 9" Southbend appears to be 7/16"x10 LH.
I bought some 3/8" acme screw from McMaster and it is clearly too
small. 2) There has been a lot of talk of leaving machining the
mounting boss to the end user. How? When I machined a block of brass
to hold the ballnuts I retrofitted into my 13" SB, I setup the acme
screw in a 5C collet block on the mill, put the old nut on that, and
found it with an indicator. Then I switched collets and put in a
piece of rod I'd threaded to match the mounting threads on the
outside of the ballnut (same thread as used for mounting off the
shelf acme nuts), screwed my nut carrier onto that, and tried to
mill the boss before the setscrew keeping it from rotating failed.
(I saw a post here about someone else who had done essentially the
same thing) It came out loose, and so while I don't have any
backlash in that screw and nut, I have about .002" inches of play
between the nut carrier boss and the topslide casting. I'm getting
severely tempted to put roll pins through the topslide into 2
corners. 3) What about just using off the shelf acme nuts mounted in
a carrier as above? Or are they not available in left hand thread?
4) What about casting nuts in place from babbit or low melt alloy?
5) What about moglice? Okay, I must admit I'm dragging my feet on
this as I have a small can sitting in my shop unused. I'll make the
following offer - if there is someone local to the Boston area who
wants to help me figure out how to actually get that project
accomplished they are welcome to bring their saddle/topslide
assembly over and do theirs too as I can't mix up a small enough
batch to do only one nut. I'm pretty sure it would be desirable to
cast it in place, unless one wants to go through the boss machining
hassle in number (2) above. It is my desire to buy new screw stock
and machine the end on it for mine, both in case the moglice proves
impossible to remove, and because I want to use a trantorque bushing
on the handwheel end instead of the SB pin key to make swapping the
handwheel for a timing belt pulley easier. Chris (2908) |
| I have used Loctite
Form-A-Thread for everything except head bolts on old Harleys with
good results. Has anyone tried it in an application like a
feedscrew? I wonder how well it resists abrasion? (2911) |
| Heavy 10
crossfeed acme leadscrew dia |
| I just removed the
crossfeed and took out the brass nut to see if something could be
done about the backlash... but it appears to be 0.4" major dia and
0.333" minor dia * 10 TPI acme. Q#1 Maybe its really a .375" dia *
10 TPI acme? Does anyone know for sure? Q#2 Is the 10K and 9A/B/C
also the same? Q#3 I was quoted US$68 from Southbend for a new nut.
Are there any other sources? (I'm just measuring the nut, I can't
really get at the acme leadscrew itself to measure it without taking
it out). Doug (4123) |
| 7 / 16 x 10 ACME on
my machines. A '59 and '72. Best to go nut AND screw. You can make
them. Shape the nut with a mill. Cut the internal thread with a
single-point cutter in your 4-jaw. This way you can control
the fit to get it tight. The taps I have found are too
sloppy. (4124) |
| The screw
is 7/16 10 acme left hand a real odd ball I never found a tap or die
for such critter when trying to do work on this size . You can get
1/2 10 in whatever you need but SB did a odd size here. If all parts
are wore out you could probably go 1/2 but for just a nut I would
say either make a tap and restore your nut for a project or bite the
bullet and buy one. I think there are pics of someone posting
restoring one and a really nice job but didn't see how they did the
threads . Jim (4126) |
| Cross feed disengagement |
| Can anyone
tell me how to disengage the cross feed screw so I can use a taper
attachment on my SB9C? Any help is greatly appreciated. I don't have
a taper attachment yet, but do have some plans for one. I was told the
taper attachment is easier to use instead of setting over of the
tailstock to do tapers. Bill C.
(8189) |
| There is a special
2 piece version of the crossfeed nut that is used with the taper
attachment. It uses a bolt to hold the 2 pieces together. When that
bolt is removed it frees the cross slide to use the taper
attachment. Check out
http://groups.yahoo.com/group/mwhints/files/Boring.pdf
which I think is pretty neat and easier than making a taper
attachment.
(8190) |
| Bill You might call
Dick in Detroit; he probably has one of these 2 piece nuts.
Lew (8191) |
| Steve. Thanks for
the link. This is a much better design than the plans I have. This
will be a good project to gain some experience. Bill C.
(8193) |
| Steve Checked
out the boring head; I LIKE IT! Looks like it might
even be simpler to use than the taper attachment. Lew (8194) |
| Lew and Bill The
boring head idea is a good option to use for small tapers.
Clint (8195) |
| Lew, Clint and
Steve. I found a set of plans for an Offset tailstock center that
would serve the same purpose. Looks really easy to build. Consist of 6
pieces including a #2MT center that has been threaded on the large
end. If anyone is interested in these plans, email me off list and
I'll send copies to whoever wants them. It basically like setting
over the tailstock. Except you set the offset center instead and the
tailstock stays centered. Bill
(8198) |
| Bill I would like
to look at them. have you looked at the off setting a boring head in
the tailstock method yet? Clint(8199) |
| Clint. I
downloaded another set of plans for a homemade boring head. I will
send you both of these files via your email. A boring head would be
nice but they're kind of expensive. About 80 bucks for a cheap one. I
probably have enough scrap to build the offset center though. I can
make the #2MT from an old motor cycle transmission gear spindle. Of
course the spindle will have to be annealed before I can machine
it. This will also be a good chance for me to try some screw
threads. Don't know if I'm really ready for that!! Be looking in your
email for the plans. Bill
(8200) |
| Is this something
you could post in the files section, Bill? Fred (8201) |
| Bill OK, I have
the plans using a boring head, I was just wondering if you had them.
But I am very interested in you using the motorcycle parts.
Clint (8204) |
| Replacement
cross feed nut |
| I'm looking to find
how much it will cost for a NEW replacement cross feed nut for a 10"
Southbend lathe. Also, is the manufacturer the only point of
purchase. (8926) |
| I bought a new nut
for my heavy 10 - cost $65. You have to buy S.B. parts from LeBlond
L.T.D. Don't know of any other source. (8927) |
| Wasn't there a
list member making these? Lurch (8928) |
| No, there are
several "private brands" Try Plaza (8931) |
| Plaza Machinery
sells them. When I bought mine they were $35. He also sells thread
stock to sleeve into your present cross slide lead screw. He also
rebuilds them. I think the price for a rebuild was $65. There is a
difference in the nuts depending if you have a taper attachment or
not. At least on the 9/10K. I can't say on the Heavy 10 (10L). I
don't have the number for Plaza handy at the moment. Tom (8945) |
| Crossfeed nut
question |
| Could someone
please explain the actual physical difference between the x-feed nut
for the 9"C [non-taper attachment] and the nut for the 9"A B
[taper-attachment models? Can the C-type be modified to be identical,
or at least suitable? In the event drawings are needed to explain
it, I can read DXF or DWG, as well as Mastercam. Johnny
(9003) |
| The Non-taper is a
cylinder with the thread perpendicular to the cylinder. It fits
into a round hole. The taper attachment one is sort of an extruded
triangle length wise, with a rounded top. The flat base fits into a
shallow recess. Really very different and would be best to just make
or buy one. I do notice that you are referring to "C's" as non-taper
and A B's as taper. This makes me wonder if you are wanting power
cross feed. Many A's and B's don't have taper attachments. Maybe
some C's had it. Now if your thinking about power cross feed, that
has nothing to do with the nut itself. That has to do with the cross
slide leads screw. These are different and again might be a bit of
work along with work to the lead screw and an A/B apron. Tom(9004) |
| Tom, can you be a
bit more specific? I bought an aftermarket taper attachment for
mine, and although mine has the non-taper crossfeed setup, all I do
is unwind the feedscrew until the nut disengages, then unscrew the
bushing from the carriage and remove the entire feedscrew
assembly...is the 'triangle-with-rounded-top' design supposed to
allow disconnection without physical removal? (9008) |
| Brian, The Taper
type nut is a solid piece. It is not a disconnect type. I haven't
looked at the design intent as to why there are two different types
of nuts. I would think the taper nut is such so it won't twist with
any side forces from the taper attachment. SB taper attachments use
a different cross slide. It has the long slot that the taper
attachment connect to cast into it in one piece. This is for the
9/10K only. The heavier lathes have it bolted on. If I was to use
the non taper type nut and cross slide and its nut does twist in
operation with the taper attachment, I would think of putting in a
keyway to keep it aligned. Still, I would check into this a bit
more, If I were you. Tom(9009) |
| Yep...this
aftermarket taper attachment comes with an extension that bolts to
the stock cross-slide...but if I have to remove the leadscrew
assembly to cut tapers, how then could that affect the nut? (9010) |
| Brian, I don't know
the design intent or operation procedure for your aftermarket taper
attachment. I don't understand why you are removing the leadscrew.
If so then how do you adjust for different cuts of diameter? If I
couldn't adjust the depth of cut, I would say this is a poor design.
I'd stick with offsetting the tailstock, then. The two operations
that a taper attachment is necessary for is large pipe threads
(generally pipe threads over 1 inch) and precision ID tapers. I have
operated taper attachments on a few commercial lathes. These, you
didn't disconnect the cross slide lead screw. You did make sure the
taper attachment's bed clamp was loose if you weren't cutting a
taper. I hope this helps. Did you get instructions with this piece?
Do you have photos of it? I think the home built taper attachments
that there are plans for operate much the same as the commercial
units. Tom (9012) |
| On my heavy 10
original taper attachment the cross slide screw is disengaged and
the cuts of diameter are adjusted using the compound. (9013) |
| I have both types
of nuts for my SB9a. I converted my machine to taper attachment last
summer. The standard nut and the taper nut are essentially the same
except that the standard nut has a round stub that fits into the
cross slide casting. The taper nut has basically the same dimensions
for the cross slide screw, but is flat on the top with a 5/16x24
thread to secure it to the cross slide. I actually modified a
standard nut to use on my taper attachment. I will post a couple of
pictures tomorrow. Pete (9016) |
| Lurch writes: Yep...this
aftermarket taper attachment comes with an extension that bolts to
the stock cross-slide...but if I have to remove the leadscrew
assembly to cut tapers, how then could that affect the nut? Looking
at the parts list it appears that the non-taper nut is designed to
be better supported where it attaches to the non-taper cross slide.
On the taper cross slide and nut they've been reengineered so that
the nut can be released from the cross slide by merely unscrewing a
bolt attaching it. This means the cross slide can be driven by the
taper attachment while the nut is still on the cross feed screw,
without being attached to the slide the nut won't interfere wit the
taper attachment functions. It's a question of which factors were of
greater consideration in each case. With no need to release the
cross slide from the feed screw and nut the better support was of
greater value on the non-taper version. On the taper version, easy
release from the feed screw and nut was considered to be the greater
value. I'm attaching a copy of the parts list illustrating the
differences. Anthony (9029) |
| Thomas.G.Brandl writes: I don't
know the design intent or operation procedure for your aftermarket
taper attachment. I don't understand why you are removing the
leadscrew. If so then how do you adjust for different cuts of
diameter? --- The 9" and 10K lathes use a non-telescoping feed
screw. If you were to leave the feed screw connected there would be
a conflict between the feed screw thrust bearings and the pull of
the taper attachment when the taper clamping lever was engaged. In
order to prevent this conflict the cross slide must be released from
the feed screw and/or feed nut. When using the taper attachment all
cross feed functions are served by the compound slide which is set at
90 deg. to the axis of the centers. On a taper attachment with a
telescoping feed screw, which is the standard on SB 10L and larger
lathes and appears to be what you are familiar with, the cross feed
screw is made in two parts which can telescope axially but are keyed
so that all rotational movements of one part are transmitted to the
other part. The part nearest to the operator has support bearings in
the front of the carriage and includes the crank and micrometer
dial. The part away from the operator passes through the feed nut,
then has thrust bearings at the taper attachment bracket which is
attached to the back of the carriage. When you turn the crank to
operate the cross feed the front part rotates the rear part which
feeds in the nut and drives the cross slide via the thrust bearings
at the taper attachment bracket. Because when the taper attachment
is in use there is no relative motion between the rear thrust
bearings and the feed nut (they are both feeding at the same rate)
the nut does *not* have to be released from the cross slide. Hope
this helps in understanding the differences between the telescoping
and non-telescoping versions of taper attachments. Anthony
(9030) |
|
Crossfeed nut-success |
| Just a
comment. I purchased a 13" about 6 months ago. It appeared to be in
good shape. I have enjoyed working with it. I did notice that when
using the milling attachments, it would overfeed and jump at times,
breaking carbide bits. The measured slack in the crossfeed was about
30 thousands, but that didn't bother me since I had looked at some
cheap new lathes with more than that. (I measured this with pressure
in both directions.) As an experiment, I reversed the crossfeed nut
and about half the slack disappeared. I don't know why that would
happen but it did. However, I still had problems due to slop. A
closer look at the system showed that the slop was the same over the
entire travel of the cross slide. Measurements of the screw diameter
showed it to not be worn as far as diameter is concerned. This,
coupled with the fact that the screw is hardened steel and the nut
is bronze lead me to the conclusion that all I needed was a new nut.
After looking at the price of taps and thinking about the problems
of making one, I decided to bite the bullet and buy one from
LeBlond. With the new nut, measured slop was 10 thousands.
Performance has improved to the point it's like having a new lathe.
Most of the work I do is on guns which requires some pretty close
work, and the difference is amazing. I guess the moral of this is
that if you need close tolerances, the cost is worth it, and might
not cost as much as a lot of people fear. I see a lot of mention of
astronomical "screw and nut replacement costs". I suspect this isn't
necessary in the majority of the cases.
(9110) |
| How much were those
nuts if you don't mind me asking? Alex (9111) |
| Cost was $74. It
arrived in two days after calling. (9126) |
| Cross feed
parts diagram |
| Does anyone have a
diagram of the parts which make up the crossfeed assembly for a 10"
SB? If so, can you post it.
(10052) |
| 10K or 10L? Anthony
(10053) |
|
http://metalworking.com/DropBox/_2001_retired_files/standardmodernarmy11.pdf
Is an army manual for a 10" south bend lathe. There is a diagram
there. There is also a manual for a 9"/10K with lots of exploded
drawings.
(10055) |
| Umm, no. First
of all, the proper url is:
http://metalworking.com/dropbox/_2001_retired_files/standardmodernarmy11.pdf And if that is broken across lines, you can use:
http://tinyurl.com/8nv7
Second of all, as indicated by the filename, that is *NOT* for a
South Bend Lathe. It is for a Standard Modern Lathe, quite different
from a South Bend (and not even made in the same country :-))
Finally, anyone interested should know this document is a about 1 Mb
in size, so users with a dialup connection may want to take a coffee
break while downloading. There *IS* a manual at the same site for
the South Bend 9" Lathe (Model CL 670Z), it is at:
http://metalworking.com/dropbox/_2001_retired_files/sbarmylathe.pdf
Or http://tinyurl.com/8nw0 Again, be forewarned, the file size is
about 1.2 Mb. -- Scott Logan (10058) |
| Cross Feed
Screw |
| Please can someone
explain how the "cross feed screw " by which I take it you
meant the
feed for moving the cross slide can work in compress on one model
and in expansion on another, surely it must work in both modes as
the cross slide is moved back and forth? The implication is that
cutting usually takes place on the front of the work piece and that
cutting is when the feed screw is most heavily loaded and when
precision is required. A feed screw fitted without a taper
attachment has its thrust bearings at the front of the lathe. When
cutting there is a compression load between the work piece and the
thrust bearings which tends to make the feed screw flex out of a
straight line. The same applies to a non-telescopic feed screw. A
telescopic feed screw, as used on many taper attachments, has thrust
bearings at the front for the ball crank and another set of thrust
bearings on the taper attachment for the back section of the feed
screw. The back section is what adjusts the position of the cross
slide and the cutting tool, so when the cutting tool is being
engaged with the front of the work piece the screw is pulling from
the rear instead of pushing from the front. In this pull, or tension
mode, the feed screw is being held in straight alignment, that's
the nature of mechanical tension, so it should give greater
precision in controlling the position of the cutting tool. Does this
answer your question? Anthony
(10427) |
| J.W. Early writes: Anthony did I get
it right this time?? Yes. You'll notice I just sent in another
response. The person asking the question wasn't making a distinction
between when the screw was under load and when it was just moving
the unloaded slide, I tried to clarify the difference and why one
was significant and the other not. Now because of the fact that the
threaded portion of the feed screw is retained at the rear in the
taper slide instead of the front in the carriage it now operates in
tension as against the normal lathes compression load factor. This
is only one of several design features of South Bend lathes that
while almost invisible to the average user give them a special
flavor for those who see and understand the advantages these unique
features give these machines. In fact many lathes with taper
attachments use a telescopic feed screw but the smaller ones, the
ones most hobbyists have experience with, are less likely to have
high end features such as this. Anthony
(10429) |
| Model A power
cross feed? |
| How does the power
cross feed work? (I have the manual coming next week) (Please read
the below only with the understanding that you did not know the
names of all the parts at one time as well) So here is the break
down. Hand wheel, next to it and smaller, little flower knob, next to
it and up is the lever with three "indexed" positions, then the
right is the lever that goes up and down about 60-90 degree sweep.
If I guess right, the indexed lever is for off cross and
longitudinal power movement, and the lever on the right is for
engage/disengage. None of them power feeds anything.
(10781) |
| The left most
hand wheel is the manual longitudinal feed. The "little flower knob"
drives a clutch and is use to engage (clockwise)/disengage (CCW) the
power feed. The lever with three "indexed" positions selects
between: UP (power longitudinal feed), middle no feed (allow use of
the half nut lever) and down (power cross feed). The level at the
right only engages the half nuts, typically used for threading. The
half nut level can only be used if the power feed selection lever is
in the middle position. Tom (10782) |
| I was pretty
close. So if I engage the "flower knob" and nothing moves, even when
the indexed knob is in the up position (or down), what does that
mean? Is this the stuck clutch I read about here? Also, aside from
the obvious, what's a half nut? Steve (10783) |
| Handle on far right
down: "Flower" knob is the friction clutch...turn right to engage,
left to release. Left lever (To right of flower knob clutch): All the
way up uses the clutch to longitude feed. All the way down uses the
clutch to crossfeed. Center position allows right hand lever to
engage halfnuts to feedscrew for threading by raising right hand
lever. All Feeds are reversed by the reversing tumbler at left side
of head. Don't feel bad: I dunno what to call the clutch knob,
either. "The fluted thing that looks like a faucet"? ( 10784) |
| My opinion for
what's it is worth: I would suggest getting a copy of the "How to Run
a Lathe" book or consult with an experienced operator in
person. Lathes, especially older ones are not that user friendly and
its really not a safe tool to just learn by doing with no references
or instruction. (10785) |
| Already have the
book on the way. As far as consulting with an experienced operator, I
am attempting, but it is not as easy as it sounds. This is my means
of doing so, and BTW, I do value your opinion.
Steve (10790) |
| Steve, you may see
if you have a local vo-tech school that has a machine shop - Being
in a similar situation to yours, I took a night course in the fall
and liked it so well that I took another in the spring. Now I just
bought a Bridgeport mill to go with my Heavy 10 - looks like I
caught a bug. John (10796) |
| Steve, there are
two separate power feed systems in the model A, one for the power
longitudinal and cross feeds, and one for cutting threads. Both are
driven by the lead screw, the long horizontal screw that runs along
the front of the lathe, under the bed, and that goes through the
front of the apron (the bit with all the controls we have been
discussing). I'm not sure how much of this you know already, but
here is a description for beginners (a couple of years ago I knew
next to nothing, too). To get a power feed, the lead screw must be
turning. Look at the left hand end of the lathe. There is a gear
train all the way from the spindle at the top, through the reversing
gears, then an adjustable gear train (which you can use to cut
metric threads if you have the right adaptor gears, and which owners
of B and C models use to get the different power feed speeds),
eventually down to the lead screw at the bottom. And on the A, the
lead screw goes through the gearbox, on which you need to engage a
suitable gear. It might be stating the obvious, but is the lead
screw turning when you are trying to get power feeds? Now to how the
lead screw provides the power feeds. As I said, there are two
separate systems. The power for power longitudinal and cross feeds
comes from the keyway in the lead screw. It turns a key, which is
captive inside a geared sliding collar arrangement, which turns and
acts through the clutch knob and 3-way lever to turn the power
feeds. The power longitudinal feed acts by turning a pinion, which
acts on the rack on the underside of the bed. The feed for thread
cutting is through the half nuts. Imagine a wide, strong nut on the
lead screw. The nut is attached to the apron, so when the lead screw
turns, the nut moves the apron along at a controlled speed with
respect to the rotation of the spindle. Now, to allow this nut to be
disengaged, it is cut in half lengthways, so it can be unclamped
from the lead screw. Hence the term, "half nuts". The right hand
lever on the apron clamps and unclamps the half nuts. Notice that
the two feeds use the lead screw in two completely different ways.
The thread cutting feed relies on the thread of the lead screw,
while the power longitudinal and cross feed uses only the keyway,
and relies on the rack for longitudinal movement. Some larger lathes
use two separate shafts for these two purposes, but the A combines
them on the one shaft. "How to run a lathe" is a useful book, but
does not tell you everything. It is not the encyclopedia its name
implies. Look for other books or training manuals, keep asking
questions on this list, look for knowledgeable people around your
area, maybe even do a short course. Whatever works for you. Roger
(10798) |
| So after that
bit of info, I went and looked at the lead screw. No it isn't
moving, so I opened the sidecase to look at the gears. There are no
gears engaged with it. (Photo on
http://www.turningwood.com/southbend.htm )
Are there gears missing or something? The gear that drives the
leadscrew doesn't touch the gear driven from the headstock. Does it
just need to be adjusted? I can turn the leadscrew gear and it will
turn the leadscrew. Maybe something is jammed in the tumblers? Also,
on the tumblers (dual tumbler gearbox), should I be able to just
move the tumbler from position to position? It is pretty tough and
the left one won't seem to find another position. Steve
(10841) |
| Steve from what I
can tell, you can adjust the gearing to all mate up/e should be the
forward/reversing gears then the e20th stud gear to drive the 80
tooth, then on the leadscrew a 56 tooth Just turn/adjust the banjo
to position with moving the 80 tooth, once you get the gearing
connection, before firing it up, loosen the clutch and make sure the
power cross feed lever is in neutral, and the half nuts are not
engage, then put power thru to make sure all the gears on the
headstock are running smoothly and not to tight, then commence to
engaging the apron gears, etc. Clint (10844) |
| Steve I forgot, as
far as moving the gear handles on the gear box, try turning the
leadscrew some while moving and engaging the levers, this helps a
little to lining up the gears to slide into position, these can be
stubborn at times, what ever you do, do not over force it, please do
not use a hammer. Clint (10845) |
| Steve, As Clint
mentioned, you need to move the large 80 tooth "idler" gear so that
it engages the inner 56 tooth gear on the input for the gearbox (the
outer gear on the gearbox is not used). But you also need to make
sure that the 80 tooth idler gear also engages the 20 tooth "stud"
gear just above it. In order to do this, you will need to adjust the
position of the 80 tooth idler gear. The 80 tooth idler gear is held
in position by a nut-stud-bushing assembly which clamps the gear to
the bracket (called the "banjo"). This is the nut in the center of
the 80 tooth idler gear. In order to get the gears to "mesh"
properly, you will probably have to adjust the banjo bracket also.
There is a "pinch" bolt located between the 56 tooth gear and the
circular shield of the gearbox (usually an Allen socket head cap
screw but older machines used a square head bolt) that holds the
banjo bracket rigidly in place. What I would recommend is to clean
the gears first. This will allow you to get the proper meshing
(engagement) of the gears without a false measurement due to debris
when you go back together. Also, South Bend Lathe recommends using
oil instead of grease on the gears. Loosen the banjo bracket pinch
bolt and rotate the bracket with the 80 tooth idler gear down and
out of engagement with the 20 tooth stud gear. When the gears are
clean, loosen the nut in the center of the 80 tooth idler gear and
slide it along the banjo bracket until it engages the 56 tooth gear
on the gearbox. In order to get the proper mesh of the gears, place
a piece of cigarette paper between the two gears when meshing. This
will give the gears the proper "backlash" (clearance). Then tighten
the nut on the 80 tooth idler gear and then roll the gears to remove
the cigarette paper. Next, swing the banjo bracket and 80 tooth
idler gear up to engage the 20 tooth stud gear. Again, use a piece
of cigarette paper to set the proper backlash. Tighten the pinch
bolt on the banjo bracket and roll out the cigarette paper. Now
you're set! I also noticed that the "reversing" gears are set in
neutral. These are the two gears just above the 20 tooth stud gear.
They are engaged by rocking the "tumbler" up or down (center is
neutral) Up is forward, and down is reverse. Okay, now you are set.
Webb (10858) |
| There are drawings
of the gear train in the how to run a lathe book. There are also
scans of it in the files section and at the faq site. you might want
to look at the pic as you read webb's write-up. dennis (10859) |
| BTW, here's an old
low-res picture I made to show the proper setup of the gear-train.
Note the 40T stud gear is simply being stored on top of the 56T
input to the QC gearbox. Swap it with the 20T stud gear to cut the
coarse threads as indicated on the gearbox plate. Paul R. (10861) |
| What then would be
a good basic gear set-up for general finish work on a model C?
Something I can leave on there most of the time please. I have no
gear set, but would like to begin buying, and want to start with the
most useful first. I'll confess that the math of these things
leave me cold. Len (10862) |
| I should also have
said that I have a running set on there now, of course, but have
never counted the teeth, and only the 80 is stamped! Len (10863) |
| I setup the gears as you all told me, and
got the power feed going. Sort of. It would bind in some spots, so
what the hey, I yanked it apart and rebuild it. It had POUNDS of
crap in it. A lot of plastic and some metal shavings. A gallon of
parts wash later and she looks wonderful. Stripped the paint and
wire brushed it for that modern sorta shiny cast iron look. Thanks
to everyone here and posts, I was able to rebuild it with little
problems. Does need new half nuts though (I even know what they are
now). I understand someone on the forum rebuilds them, can you pass
along the name for me? Steve (10889) |
| Too much play |
| I have a Southbend
Model a Workshop Lath with a 4'bed and cast iron legs. The serial
number is 103656 and it has L.O.R. stamped under the number. I
believe it was manufactured before 1941, maybe 1940. My lathe has
.026" of play in the cross feed and .045" of play in the compound.
By play, I mean that you can move them that much with out turning
the screws. I am not sure if the play is caused by ware or if it is
somehow out of adjustment. I believe that I would have to destroy
something to take apart the crossfeed and compound screws because
someone had burred over the spanner holes in the nuts that hold the
handles on the screws. Does anyone have any advice on how I can take
up some of the play? Gary (11623) |
| I would like to add
that my SB 9"model A has a #3 Morse Taper in the head stock. Other
information I have read said that it should have a #2 MT. Does
anyone here have a 9" with a #3MT ?
(11633) |
| The standard IS 3MT
headstock, 2MT tailstock for a 9". Paul R. (11635) |
| Sure! My '39 has
MT3 headstock, MT2 tailstock. The 13's had a weird taper, but every
9 incher I ever heard of has MT3 in the spindle. Stan (11645) |
| Crossfeed Nut |
| I read in someone's
post that you have the AS65NK1 crossfeed nut for a 9" or 10K lathe
without a taper attachment for sale for $67.00. How do I go about
ordering one. Can I call you and give you a credit card number or do
I need to send a check? Please give me the proper address and
phone#. Gary (11684) |
| Gary- Please
contact me at 888-532-5663 X216 or email at
rmarvin@leblondusa.com
Rose (11690) |
| Rose: On my last
Email to you I meant Crossfeed Nut not Carriage Nut. Sorry! I have
another question. What purpose does the the set screw (20)and the
pin (18) that comes as a subassembly with the Crossfeed Nut (19)
part # AS65NK1 serve? Gary(11721) |
| Gary, I'm not Rose,
but the setscrew has a 60 degree taper on the end that bears on a
tapered pin forcing it against the side of the compound slide
mounting hole to keep it in place. Run on sentences are one way to
avoid punctuation difficulties. Glen (11724) |
| Glen: Thanks for
responding. However, I have mine tightened but the crossfeed nut
stills comes out of the hole if I take the cross slide off. What
would be the need to attach the crossfeed nut to the cross slide
when the hole in the cross slide traps the cross feed nut anyway?
Gary (11729) |
| Has anyone ever
tried to repair a worn-out crossfeed nut of a Sb 9"? If so how did
you do it and how did it work. I found a used Acme 5/8- 8 tap today
for $.99 with the thought of maybe making a new crossfeed nut. As
luck would have it my modal A 9" uses a smaller screw. Gary (11730) |
| Gary- the threads
are 7/16-10 left hand acme. long story...search the archives. Does
the cross pin move freely in the hole or is gunged up? try cleaning
it. check the 60deg point setscrew too, make sure its a FULL point.
You need to trap the nut as there is no outboard bearing on the
screw. It will waller everything out. dennis
(11731) |
| Dennis, Would you
explain please? The nut is supposed to be free to turn? What 60
degree set screw? We are talking about the cross slide and not the
compound, right? Please forgive all the questions but this is
exactly what I am trying to fix right now and this is all new
information to me. Jim (11732) |
| Dennis: Thanks. I
had not realized they were LH threads. I read the article in the
files about the shop teacher who rebuilt some cross slides for his
school and did not recall him saying anything about LH threads. The
LH treads just killed any of my thoughts about making a new
crossfeed nut. I guess I will just buy a new $67.00 one from Rose. I
am still interested to find out if anyone has successfully repaired
their crossfeed nut. How about telling your long story. I am
guessing it goes something like mine would have if you had not
pointed out they were LH threads. Gary (11733) |
| Being bronze, the
nut can be planished tighter onto the thread by tapping with a
hammer (with a lot of care). Continuing free movement needs checking
all the time during the process. I know this sounds like (and IS) a
bit of animalism, but as a short term measure it works. I did this
on an old lathe some years ago, and the "repair" worked successfully
until I scrapped the thing because it was knocked over when
shuffling a cart into the workshop and cracked the bed. Len
(11735) |
| I made a new
crossfeed screw and nut right on the lathe, but it has been about 10
ago. I didn't know they could be purchased at the time. As I
remember, I made the Acme screw first, getting it as close as
possible to an Acme thread gauge, then forged an internal threading
bar out of 1/4" music wire, heat treated it and ground it to the
thread gauge. Then it was simply a matter of threading the nut until
the screw I made was a snug but free turning fit. At that point I
cut the old crossfeed screw off right ahead of the power crossfeed
gear, took what was left of the old screw to another lathe and
drilled it out to accept a stub tang on my new screw. Epoxied and
pinned in the new screw section, and I was in business. I know this
is vague, but it can be done, using the old parts for a guide. This
repair has been working well since. Obviously if the parts are
available, it depends on which is more valuable, your time or money.
(11736) |
| How were you able
to turn a left hand thread? Or, did you use a right hand one. If you
used a right hand one how long did it take to get use to turning the
hand wheel backwards. Gary (11737) |
| Jim, The crossfeed
nut is shaped like a T. The cross bar part of the T is threaded 7/16
x 10 Acme. The other part of the T is drilled and tapped for a
setscrew along the axis of the part. It is also cross drilled for a
pin. The set screw and the pin have a taper on the ends. As you
drive in the setscrew, it forces out the pin (at 90 degrees to the
screw) which impinges on the inside of the cross slide hole. As a
last step when assembling the whole thing, you tighten down the set
screw. HTH Dennis Pantazis and I have both made replacement cross
feed nuts. Dennis had some kind of CNC milling set up that
fabricated beautiful looking nuts. For my homemade nuts, I single
pointed the Acme threads on my lathe and continually trial fitted
the screw until I got a tight fit. I had one of Dennis's nuts on my
lathe while I was machining a MLA milling attachment. I used a big
carbide cutter in a 4 jaw as a fly cutter. I think the interrupted
cut on a big cast iron piece ruined the threads, at least I got a
lot of back lash after that. I sent one of my home made nuts to
Crazy Bert who was happy with it at first, but after a "milling in
the lathe" incident, he had a lot of back lash, too. Maybe the best
solution is to buy replacement nuts and screw from Rose. Glen
(11741) |
| Glen, I guess I'll buy one from Rose too. Seems like a
vital, although seemingly simple, part to cheap out on. Jim (11750) |
| Jim, The nut alone
may not solve the problem. If there is a lot of wear on the screw,
the nut won't fix it. There is a description in the files area (I
think) on how to fix it with a piece of LH 1/2 x 10 Acme rod and a
machineable nut from MSC. I bought some to try someday. Glen (11751) |
| That was the case
with mine. I had posted about the fix last month. Let me see if I
can find the story...... Here it is: My Model A was built in 1952,
so was old when I got it. Since I got the lathe, I have manufactured
about 2,000 parts that are 8" diameter, and faced on 3 sides(!). One
power feed pass to clean the casting and make a datum surface, then
the part is flipped on the vacuum chuck, and faced. The first face
is then refaced to assure plane/parallel to In the course of this
product manufacture, the power crossfeed has therefore cycled more
than 6,000 times at a slightly more than 4" excursion. On E-Bay I
got a screw and nut from a Model C. Upon removing my crossfeed screw
and comparing them I could only stare dumbfounded. The very thread
profile in the worn region did not resemble an Acme screw, but
rather something with a very thin (-.008) form! So knowing the Model
C had no power crossfeed I reasoned that the wear could not be as
bad, and it certainly is not. So I intend to use the Model C screw
to run the lathe so I can part off the gear section from the Model A
screw, and then bore the gear to .441 and press and pin (Or silver
solder it) the to correct portion of the Model C shaft. Sounds like
fun. I'll let you all know how it works out. I may photograph the
process and put it on my site. The Model A screw assembly is a total
loss, anyway, as there is radial slop in the crank bearings!
Otherwise, I would be trying to rustle up a 12 tooth 20 pitch
pinion. (Later that night) Damn I am good. 45 minutes, being
careful, and it works great! One thing, though. I confess to
sweating bullets when I checked the bottom of the gear teeth, that
is the ID of the pitch circle. I only had .018 wall after boring the
.441. Whew. Drink Time. With my Foredom and a slitting wheel, I put
longitudinal grooves on the mounting surface to insure silver solder
flow, 6 equispaced .010 deep, approx. I heatsunk the screw to
prevent annealing. So this fix was a piece of cake. Without power
crossfeed it appears the Model C screw was nearly new. it had a MUCH
easier life than the one in my 1952 Model A. (Or a lazier
owner. haha.) Got a nut also. It amazed me how much the Model A
assembly rattled around when shaken...the original was really,
really beaten up. I wonder if the PO was machining ceramics on it or
something. (11752) |
| I didn't read back
far enough on your posts to see which model lathe you have, but I
think they all have the feed reverse lever coming out of the gear
guard, far left on the headstock. Center position is neutral, the
lathe runs without the feedscrew turning. Down is normal, carriage
moves towards the headstock, and the up position moves the carriage
away from the headstock. You can do a left hand thread just by
putting that lever in the top position. If you turn a leadscrew,
you'll probably need a follow rest, the screw is long and springy.
I'm remembering more about this now, I did it mainly because I had
never had a lathe that would cut threads before, and so I thought
turning the screw and nut would be a good exercise and a chance to
make something useful. (11755) |
| I can assure you the
crossfeed nut Glen made for me was a beauty a real piece off
workmanship which I ruined when I was trying to mill with the lathe
still
mad at my self on that. Bert (11767) |
| I just received the
new crossfeed nut I ordered from Rosie. To install it I had to tap
it into the cross feed casting with an Alu. hammer. The old one was
a slip fit. Anyway it took all the play out of the crossfeed. I put
a dial indicator on it and the .0001 needle did not move when I
applied pressure to the crossfeed. The backlash has been reduced to
.002", I believe that is better than the original specs. The
handwheel turns a little tight, may be too tight to use the power
crossfeed? However, I think it will loosen up as it is used a
little. I was a little worried that there was too much wear on the
crossfeed screw because of the postings about people needing to
replace their screws. My screw looks polished where the nut travels
but there are machining marks on it beyond where the nut travels. I
believe that the screw is not likely to wear out unless someone uses
a tool post grinder a lot and the grit becomes imbedded in the nut.
Anyway, my lathe is now the precision instrument it was meant to be
and I am happy! To think I put up with the play in the crossfeed for
the last 24 years. Gary (11823) |
| Crossfeed nut
replacement instructions |
| Can anyone point me
to a prior post or file that will lead me step by step through the
disassembly process for getting to my crossfeed nut? It's a 1955 10"
Model A. Gene (12291) |
| Run the cross
slide all the way back until the feed screw comes out of the nut.
Push the cross slide off of the dovetail, you may need to loosen the
gibs to do it. Loosen the screw in the cross slide nut boss. You can
see it from the top of the cross slide. Wiggle the nut a little to
force the retaining pin back into the boss and pull it out from the
bottom. Glen (12375) |
| Cross feed -
compound rest slop |
| The cross feed on my SBL9B
has about 1/2 turn of backlash. When the back lash is taken out,
then it's OK but really annoying. It seems the cross-feed handle
just needs drifting further onto the shaft. I cannot work out how to
get the CF assembly apart even from the parts diagram. The handle
will not budge for a start. Next one is the compound rest, when the
two grub screws are slackened to allow the rest to be swiveled the
whole thing can be rocked back forth! That can't be right. I've just
got the lathe am struggling a bit to diagnose the problems. I bought
it from a guy who after striking the deal, dismantled it to get it
home, it's never been the same since. It was a good price the
overall condition tells me that it's OK, just put together
incorrectly. Any ideas or maybe an online Haynes for SBL's?
Incidentally, does anyone know of a UK spares agent? I know Boxford
bits are mostly interchangeable, just in case my problem is a bit
more than a missing shim. Jon
(12545) |
| You need to unscrew
the whole bushing assembly from the casting as a first step. There
is (usually) a hole drilled into the bushing on the bottom side for
a spanner wrench. I used the tommy bar from my Sherline chuck on one
of my lathes. The bushine is right hand threads. If all else fails,
try padding the bushing with leather and clamping it in a vice. This
worked on my other lathe. The next hurdle is the nut that holds the
crank handle on the screw. This is (usually) a slotted nut. A big
screwdriver with a bite taken out of the middle will work. There is
a picture of a neat tool to do this job in the files section. I used
a piece of drill rod with shoulders milled off to make a screw
driver blade and then took a pass with an end mill through the
center to span the end of the lead screw. I cross drilled to accept
my Sherline tommy bar and the hardened the tool. This will all be
clearer if you look at the tool in the files section. The handle
pulls off. There is a pin that keeps the handle from spinning on the
screw. Don't lose it. Chuck the leadscrew in your lathe. Turn your
compound 90 degrees to the lathe axis. Lock the cross slide by
tightening down one or more gib screws. Face off the surface of the
lead screw that the crank handle seats on. Try fitting it all
together. Measure the endplay. Face off. Repeat. If you overshoot
you can face off the screw on the surface that runs on the inside of
the bushing to increase clearance. Somewhere I have a page from a SB
publication that shows how to install a new cross feed screw. It
shows this whole process. It might be in the army manual. I will be
posting a procedure on how to install ball thrust bearings on your
leadscrew as soon as I get the pictures ready to load. Snip
slackened back Snip Take the whole compound off by unscrewing the two
"grub" screws all the way and jiggling the assembly until it lifts
off. There must be some swarf under it or maybe one of the pins that
holds the compound in place is upside down. to Snip Have a look in
the FAQ's that Dennis Pantazis is editing. Search on FAQ to find the
link on the list or I'm sure someone will jump in and provide it,
since I cant remember what it is at the moment.
Glen
(12549) |
| I forgot to mention
the oil screw in the top of the cross slide. If it is screwed in too
far it could act as a locking screw. Take it out first to be safe.
Glen (12550) |
| Jon Don't know of
any spares agent I'm afraid but its no problem getting stuff sent
over the pond. Just contact Rose at LeBlond, pay by credit card and
UPS will deliver within a week. Only problem is import duty, UPS
wont give you the parcel until you pay the duty by credit or
switch card. Having paid the duty you always find that UK customs
have overcharged you and there is no way of getting it back! Usually
only a œ or two but annoying. The top slide will rock a little when
both screws are well loosened off. Makes it possible to get
the thing out without disassembling the cross slide. If it rocks
the moment you crack the screws check that the proper wedge ended
clamp shoes are in place and the right way up. I have seen a lathe
with one shoe inverted and one missing with a home bodged long
grubscrew substituted for the proper assembly. Well wobbly!
Boxford parts interchange well but there are a few quirks to look
out for, mostly in the apron cross slide region. Clive (12552) |
| The rock in
the compound rest was down to the retaining pins being back to
front, taper towards grub screw. Just the
CF play now. Jon
(12595) |
| Crossfeed slop
|
| I'm putting my 10K
back together with a new nut and I still had a lot of slop due to
the entire screw moving in out. I removed the crank and snugged up
the micrometer dial and placed a washer between the crank and the
dial. That seems to fix it, but is it an OK fix? Also, what kind of
lube should I put on the compound and crossfeed screws while I have
them uncovered? Gene (12923) |
| On my Boxford I use
a shim between the tool slide handle and the dial. This reduces the
crossfeed slop to 0.004". I have used this method for the last 20
years. Martin (12945) |
| Cross feed
and slide compound brass nuts |
| I have and old sb
nice machine were can I get those brass nuts. tony (13936) |
| Nuts can be
purchased at LeBlond Lathe Co. but probably quite pricey. They would
not be that hard to make if one has access to correct Acme taps, a
lathe and perhaps a milling machine. Use existing nuts as sample for
correct shape. Could probably buy Acme Tandem Taps in sizes up to
3/4" in either left or right hand thread for 60-100 $ (
www.MSCDIRECT.com) which is probably much less than price of nuts from
LeBlond. Also from what little info I have, a lot of SouthBend Nuts
are not available unless as part of a screw and nut assembly. Last
one I priced from Rose at Leblond was in $500 Range for regular
screw and nut and $2500 for Hardened screw and nut for 13" SB. Ron
(13938) |
| Sounds like a
business opportunity for someone with a South Bend lathe.
(13940) |
| I will be making
these items for my own lathe first at work ( traded my crossfeed
screw and nut assembly for taper attachment screw and nut assembly
which was quite worn on thread. Ordered a piece of acme threaded rod
from MSC which I will cut and turn down to fit in hole made in
original remaining piece after thread has been cut off and then
either pin or tig weld ) Will also make nuts at work and then when I
have my machine back together will think about just that idea. Have
follower so long thread will not be a problem and have a miller so
nuts will not be a problem. With a sketch or sample any one with a
working lathe could make these items. Biggest problem would be
different acme taps required for different sized lathe cross and
compound nuts. Also with repair as I am making for my own machine I
am stuck with whatever backlash comes from commercial tapped hole
and commercial Acme threaded Rod. Could work with it however and
then make a new screw to suit commercially threaded hole with
minimum backlash and then replace again. Ron
(13941) |
| Here is how we do
it: Make a short piece of Acme-threaded rod 10-thou undersized. Cast
nut in place on rod. Make or acquire tap appx. .003 under-sized. Nut
is tapped in one, easy pass. Finish-machine nut on mill. Nut will be
very snug on new feedscrew. No play. Joe (13942) |
| IMHO it is easier
to tap a piece of brass with commercial tap and then make screw to
suit. This is how we do most things like this at work when both
pieces are required except on large threads where price of tap
becomes cost prohibitive. Ron
(13943) |
| You can get
precision acme threaded rod and nuts from McMaster-Carr but it is
more expensive. Get it in alloy steel or B7 which is 4140 steel. For
your application the added cost would be well worth it. To make the
nuts consider aluminum bronze. Its very rugged stuff and will
probably outlast the original ones. JP (13946) |
| That is the
threaded rod I ordered but from MSC. Have material in aluminum
bronze for nuts also. Just need to sneak a little time at work to
complete. (13947) |
| Has anyone ever
tried to split the nut and put a take-up screw in it? Frank (13954) |
| Seems like we
discussed this a while ago and concluded that it was not really reasable.
If you recall,
I threadmilled a bunch of nuts on some CNC
setups (no I don't have any more, I have no plans to make any more).
There is not a lot of room in there to make the nut adjustable.
there is room for a 5/8" dowel pin in the chase for the nut. to
access the nut to adjust would involve disassembly of the saddle.
(13956) |
| Frank What you want
is a two piece nut with the adjustable part fitted to the fixed part
with a differential thread. This where say the screw thread is 10tpi
and you would use a mounting thread of 16tpi to give a controllable
adjustment. This was in one of the Geometer hints that was posted
earlier and I think I have seen something else also, will need to
look around for it. JWE(13957) |
| On the
subject of two piece nut for SB, just today at work I had to
reassemble an 18" VDF crosslide assembly that does feature a two
piece nut or as we call it a backlash eliminator nut. It would be
quite simple to retrofit this style to a SB. Here is how that one
worked. Nuts are as a regular nut would be except they have a
tapered edge facing back to back on each nut. Front nut or nut
nearest to compound is held with its key or spigot and with a
regular Allen head cap screw. Rear nut which features no key or
spigot is also held in by regular Allen head screw and hole in
crossfeed casting is slotted to allow this nut to be adjusted before
tightening. Nuts are assembled on screw with tapers facing each
other and then a tapered wedge is inserted at that point. When
Crosslide assembly is set onto machine then front nut is tightened
tight first and then threaded grub screw is adjusted down on tapered
wedge which in turn pushes rear nut away from front nut. Using a
dial indicator on cross slide it is now a simple matter of adjusting
down on wedge with grub screw until we have minimal backlash but
screw still turns freely. You could in practice force wedge down and
push nut so far away screw would not turn. When all is set then just
tighten up Allen head capscrew on rear nut and job is finished. A
final check might be in order in case rear nut twists a bit after
tightening and starts to bind screw. P.S. One thing I forgot to
mention is that the surface that second nut pulls up to on bottom of
cross feed assembly would have to be machined so nut sat flat and
was on centerline Any comments on whether this could work on a SB?
Ron
(13966) |
| Successful
crossfeed rehab |
| Tonight I finished
my first real project - a new crossfeed for my model A. The existing
screw allowed me to move the crossfeed forward and back probably
1/4", the screw and nut were so incredibly worn. So my fix: 1. buy
1/2-10 LH precision acme screw from McMaster 2. buy machinable
1/2-10 LH nut, again McMaster 3. Machine nut down to fit in existing
slot, with a flat on top of it so center of new nut ends up in the
same plane as the center of the old nut (if that makes sense) 4.
Machine brass 'plug' that matches what is on the flat of the
existing nut - i.e. duplicate the plug that gets the 5/16-24
setscrew that drives the pin against the hole, fixing the nut in
place. 5. Silver solder nut and 'plug' together to make complete new
nut 6. Drill and ream acme screw to receive 5/16 dowel pin, press
fit 7. Press in dowel pin 8. Cut existing acme screw off near the
pinion gear. 9. Face pinion gear using compound, with crossfeed gib
locked in place 10. Drill and ream pinion to receive 5/16 dowel pin,
press fit 11. Press acme screw, containing dowel pin, into pinion
gear hole. Voila, I have a new crossfeed screw with less than 2
thousandths backlash! I'm a happy camper. I spent quite some time
thinking about what I'd use to press the parts together, when I
finally realized I could just use the tailstock ram. Duh, yes I'm a
beginner. Of course this took me several nights, but I was just
happy it all went smoothly. When I cut that existing screw in half I
knew I wasn't going back. John
(15129) |
| Job well done!
used the old noggin didn't you? I am so surprised at the
creativeness of folks when they have limited resources at their
disposal, that is one of the reason I get all bent out of shape when
someone asks of ideas of how to do a project with the tools they
have at hand and the comments received back is well you need to get
a $2,000 machine or tool, and never answers the question on how to
do! Good work, look forward to hearing of other great creative works
from you. Clint(15131) |
| John, Thanks for
the play by play. I've been going crazy trying to find 7/16-10 LH
ACMR threaded rod (OK, I know I asked for help finding 7/16- 12, was
a bad night and got my numbers jumbled) never thought to move up to
1/2". BK (15132) |
| BK, You can always
make one. Get a length of 1/2" 12L14 steel, grind a acme threading
tool, center the ends of the bar, put between centers, and thread.
You have a good sample near the ends of the old one for comparison.
It won't hurt to try it. RichD (15136) |
| Try a company
called Nook, I get acme stuff from them. (15138) |
| It was really
pretty easy moving up to the 1/2" screw. Granted it took me quite a
while to get the nut machined down to the correct size and shape,
though. The nut I used was part 1343K34 from McMaster. Bronze, 27
bucks. The screw I just used the 1018 steel one that was about $21.
I figure in my limited usage alloy steel would be overkill. If you
decide to go this route, let me know and I'll gladly send you a
length of screw and a 5/16 dowel pin to save you a couple of bucks.
John (15142) |
| Don't know
if any of you have tried but on the H 10 nut you can buy a 1/2 10 L
H Acme tap and clean out the 7/16 nut and save yourself some work on
the nut project and you can buy precision ground rod L H 10 acme
from several places. I would make sure to use a spare worn out nut
if possible. The first time I did it I was sure I would ruin the
world but did not. Make sure if you are running a smaller lathe the od of the nut will work. Grumpy
(15143) |
| Inquiry for
Crossfeed Screws |
| I have an idea for
a new product, and would like to run it by you folks. I hope this
will not be a violation of the group's rules, and if it is, I will
apologize. We go to a number of Model Engineering Shows, including
the upcoming NAMES Expo. At each of these shows, we display some of
the products we manufacture for Logan Lathes. One such product is
various Crossfeed Screws. At each show, we get a number of visitors
who stop by, and say something to the effect of "Gee, that screw
looks awfully close to the one I need for my (South Bend, Atlas,
Clausing etc.)" Unfortunately, our screws do not work as made for
these other machines, although the Acme thread is the same, at least
for the South Bend 9" and 10" (7/16-10 LH Acme). My thought was to
make some "blanks" from 7/16" Ground Polished 1215, with the Acme
thread already cut, long enough to handle any of the needs, and the
other end long enough for the user to finish as needed. I'm not sure
yet what price this might command or require, but I'd like input on
how long each end should be. My first thought was an overall length
of about 20", with about 10"-12" of thread. If anyone has any
suggestions or advise, please let me know. In appreciation, once we
get this ready (assuming we do), I'll offer free shipping within the
US for anyone on this group who would like one. Scott Logan (18368) |
| Wonderful idea!
Please proceed! Consider the compound later. Joe (18370) |
| Scott The idea is
great and would be even better with a more suitable material for the
shaft such as high tensile 4130 and a bronze nut blank to be finish
machined by the buyer along with it. For me as a machinist it is
hard to get a smooth surface finish even with grinding on low carbon
steels while 4000 series pre heat treated stock machines to a decent
finish that would only require polishing to make a longer lasting
feed screw that would not eat up the nut in a short time. JWE (18372) |
| Scott Great Idea,
I'd buy one today! Rick (18375) |
| At this time I
remake cross feed screws and nuts for Southbend lathes 9" and 10".
With or with out taper att. Any interest?
Bruce (18376) |
| Scott I like the
idea. I have been entertaining the idea of cutting new crossfeed and
compound rest screws for my Hardinge T10 lathe but do not have the
confidence I can do a good enough job. Depending on the price, I
might go for it. I will measure the length of both of my screws and
let you know. My compound rest screw is smaller than 7/16 though.
Ron (18377) |
| I might be
interested in a cross slide screw for a 9C? Price? Rick
(18381) |
| Count me in. I have
been looking for 7/16-10 material without success. I was looking at
the possibility of changing to ball screws but the only 10 pitch
that fits is 5/16 which seems to thin. Jim B. (18382) |
| Yes Jim B. (18383) |
| Great idea. You
might also consider including "generic" nuts as well. Keith
(18385) |
| I like your idea.
Before you start, we need to establish a screw that would fit every
lathe with a 7/16" ACME thread. I guess, the minimum length would be
for the heavy 10. At least 2 in should be 5/16" dia in order to
mount on the remainder of the old part. A cross feed nut should come
with the package. The way I see it is a piece of round bronze stock
5/8" - 3/4" dia that could then be modified by the buyer to suit his
needs. If you ship to Canada with USPS, I would take one. Guy
(18387) |
| Scott, Your timing
is impeccable! I've been trying to locate acme rod for the crossfeed
screws on a pair of 10L's that I'm going through. I just did a
quickie measurement of the old screws and it looks like 7.062" for
the threaded portion and if the unthreaded stub was about 3" long
that would give plenty of length to be fitted into the existing
part. The smallest diameter on the stub measures .295" on the screws
I have. I looked at the Miller Machine site but came to the
conclusion that I could spend a fair bit of time grinding toolbits
and practicing cutting LH acme threads for the price of two of those
screws. I might even learn something to boot! Anyway, I'm
interested. Chris (18409) |
| Scott The crossfeed
screw on my Hardinge T-10 is 14.7" long and the acme threaded
portion is ~6.4" long. It has a gear just past the screw threads so
I would probably have to cut this out of the original, bore out the
center and silver solder it to the new shaft. Ron
(18410) |
| 9" crossfeed
nut |
| The crossfeed on my
well used 9" has a LOT of lash. I assume that the nut is simply worn
out. I COULD I suppose just make a new one, but that means buying a
tap that I'll probably only use once .. and a bunch of hassle. What
are these worth ? You see, there IS one for sale on eBay right now
(a new one), that will go for about fifty bucks (once "handling" is
factored in). But that seems a bit high to me. Alan (19560) |
| Question answered.
Nut went for $66.00, with another $20.00 for shipping. For that
price, I WILL buy a tap, and maybe even make a couple ! Alan ( 19563) |
| Alan- Let me know
when you find that tap. I have the same problem. John
(19564) |
| Guys, Enco has a
left hand ACME 5/8 x 8 tap for +/-$35 each. JJ (19566) |
| The nut is 7/16 -10
LH ACME. Jim B. (19567) |
| The part number on
that HSS tap is 505-6804 cost $37.65 does not include shipping. JJ (19568) |
| If you decide to
start making them for a "reasonable" price with "reasonable"
shipping I would be interested. (19569) |
| I stand
corrected. Shame on me. Here I though I had found the cridder. JJ
(19570) |
| Check with Miller
Fabrication on the links. I think they sell the nut only for about
$35. They did some work for me on gear repairs and the work was good
for a very fair price. Paul
(19571) |
| Yes, and if someone
gets a tap for the heavy ten, I'd like to put in an order with them,
too. 9" crossfeed nut Alan-(19572) |
| I have seen things
like this many times. Go ahead and get the tap. Make a few trials to
get it just right. Then turn off about ten or so before the newly
acquired skill disappears. Then sell the tap and the extras to pay
for the original project. (19573) |
| JJ - I was
confused, so I went out to my lathe and checked. eeengineer is
correct: the crossfeed nut is 7/16 x 10tpi left hand acme. For fun,
I checked the compound rest nut as well. It looks like 3/8 x 10 tpi
left hand acme. I looked on Enco's website, but could not find
either of these taps. Perhaps they could be special ordered. Anyone
else have any ideas? John (19578) |
| I did a quick
search. These guys claim 24 hour turnaround. No idea if they sell to
individuals or their prices. But the point is there are people out
there that do this. http://www.newsontool.com/ (19580) |
| Sure, we
have the taps for both of these. Cost a couple of hundred dollars,
and they are not for sale. Yes, they are custom made, and should be
ordered in sets of two or three taps. BTW, check again, the compound
nut should be a right hand thread. The Logan 9", 10", 11" and 12"
Lathes use the same thread sizes as the SB. And you wonder why the
replacement nuts cost what they do. We've had a couple of customers
purchase our CF nuts to replace the SB CF Nuts, but they need to be
modified, as the height and shape are different. There is a diagram
in our catalog that gives the general shape, and the catalog can be
downloaded from: http://lathe.com/info-req.html
Scott Logan (19581) |
| I researched this a
couple of years ago and was told by two tap companies that 3/8-10
and 7/16-10 could be made, but it would require two taps for each
size rather than the two stage taps for normal sizes. The reason
given is that the web of the tap would be to weak to take the torque
and so separate roughing and finishing taps would be needed. Prices
quoted at that time were around $40 per tap for less than 10 each
and about $20 for quantities of 40 each or better. JWE (19582) |
| Alan A couple of
other options you can try rather than buying a tap. 1. thread the nut
on the lathe 2. make your own taps 3. repair the existing nut with
Moglice ( www.moglice.com ) Somewhere I've read how someone repaired
theirs with Moglice. Moglice is a relatively thin epoxy with
powdered moly in it. From what I have read it pours almost like
water. As I recall, you screw the nut on to a unworn part of the
screw, dam the ends with putty and inject Moglice with a syringe.
The screw needs to be coated with release before hand. I don't the
price of Moglice but understand that it is not cheap. Final
solution, we should merge our lathes. My crossfeed nut is nice and
tight but the compound nut is worn out. Someday I'll have to do
something about it, in the meantime I can live with it. John
(19585) |
| I have both the
7/16 x 10 LH ACME and the 3/8 x 10 RH ACME taps. I bought them from:
Tracy Tools Ltd. 2 Mayors Avenue Dartmouth Devon UK Website
www.tracytools.com These are advertised as "for renewing feed screw
nuts". The one nut I threaded seemed a bit tight on the screw.
Probably it could be lapped in, though. The taps are not tandem.
They are finishing taps only. I could really use a roughing tap to
start the threads. Single pointing to start and finishing with the
tap would work, I guess. Price was 18.00 pounds each plus VAT and
shipping. Their catalog says they have other sizes in stock. Glen
(19591) |
| They're still
available, and they're still 18.00 GBP. That's about 33 USD or 45
CDN each, plus shipping, duty and any local taxes. John
(19597) |
| The crossfeed on my
Heavy 10 was *shot*. The nut and crossfeed screw itself had *chunks*
of metal missing. I believe it was 7/16" -10. What I did was order a
bronze "precision machinable acme round nut" from McMaster Carr.
7/16"-10 not available, so I went with 1/2"-10. Also ordered up a
three foot length of "precision acme lead screw black finish alloy
4140 steel." The nut was not available in 7/16", only 1/2" from this
source. There was enough room inside the Heavy 10 castings to fit
1/2" screw and nut with no problem. I *assume* this will fit inside
the 9" castings. Basically what I did was turn the nut in a 4-jaw
chuck to leave a boss the same dimensions as the original nut. Then
tapped to original thread size (3/8"-16 ?) for the original retaining
screw (the one with the little oil plug through it.) Just get the
distance from the centerline of the screw to the nut's registering
face the same as original. I did have to freehand mill the bottom
and sides of the nut (as viewed in the installed position) to clear
the casting in the carriage. This could be done with a die grinder
or file and patience. The original lead screw was turned down in the
threaded section to a convenient size to an arbitrary length and
parted off. The new leadscrew was bored to a tight fit and installed
with loctite. Total was $22 for leadscrew and $27 for machinable
nut. Add in an hour of machine work and it's much cheaper a tap,
plus the lead screw will be brand new. All in all it was very easy-
my first machining on my new (1943) Heavy 10 and first turning since
night course four years ago. Backlash on crossfeed is now not
measurable. The only critical part is to get the old and new lead
screws co-axial. Mine has a slight visible wobble, which give a very
slight tight spot on the end. John
(19675) |
| John, This is just
what I was looking to hear. Since the 7/16 is not really available
but the 1/2 is. You just performed what I was going to go about. The
difference is that I have a 9" and I just purchased a spare saddle
with compound that has a worn out cross feed nut. Thanks for going
where no man has gone before... I don't mind standing on the
shoulders of giants to achieve greatness. JJ (19677) |
| John I did the
same procedure about two years ago to my 13 inch ( late 1960's
model), which was perfect except for the crossfeed nut. I bought the
precision nut and screw from McMaster-Carr.5/8-8 left hand for a 13
inch if memory serves me. Anyway I use this lathe a lot, still no
backlash and on a 12 inch test bar runout is only .0006.(excellent).
I chase threads quite often and this inexpensive fix really does the
job. Mitch
(19681) |
| "Play" in
crossfeed screw |
| While
re-assembling my P W 12 X 30, I noticed that the crossfeed screw has
a bit of longitudinal "slop" or play, allowing the slide to move
slightly (along the direction of the screw) while wiggling it by
hand. The crossfeed screw is threaded into a brass block which in
turn fastens to the crossfeed slide. There doesn't appear to be any
slop between this block and the slide, so the problem appears to be
wear in the brass block. Is there a way to take the play out of this
setup, or is a new brass block the only solution? If a new block is
necessary, then I would appear to be "hosed", because I am a long
way from being able to make one myself. Wade
(22191) |
| Wade, how much
slack you got. I mean you are going to chase some slack. My old
machine is about .015. I have ran some older machines with as much
as .075 to.100 slack in them. If I don't have to chase some slack I
couldn't run a lathe. Never ran one that was brand new so wouldn't
know how that would feel. As far as being hosed take the nut out and
blueprint it, put it back in and chase a little slack and make a new
one. Duane (22192) |
| The brass nut is
made to wear first because it is cheaper to replace than the
leadscrew. You should be able to find someone to make one for you or
you can buy an acme tap and make one up yourself. Another option is
to buy a brass acme nut and make an adapter so the total unit
matches the 'brass block'. Or, you can live with the backlash.
JP (22193) |
| Wade, How do you
know unless you try!?!? Get a couple of pieces of aluminum and try.
You may surprise yourself. If nothing else, you'll learn a lot.
Don't hesitate to ask questions. Mario
(22196) |
| Absolutely. One of
the first things I did 20 years ago with a clapped out 9C, when I
knew one or two things less than now, was make a new top slide nut
out of aluminum with a handground boring bar. The thread profile
match was iffy, the threads themselves were embarrassing, but the
whole thing worked better than it did before and I learned a lot.
Still got that nut. Ed (22197) |
| I'd
estimate the slack to be about .050 or .060, so I'll probably want
to do something about it. You have all offered some really great
suggestions, and I want to thank you for that. I am considering all
of these options, including possibly making a new nut (scary for me
at this point), or modifying this one in some way with set screws,
etc., to take up some of the slack. The feed screw thread is
5/8"-8TPI-LH, with a 5/8"-18TPI-RH hole in the top face for the
cross slide attachment bolt. This hole has a 1/8" oil hole at its
bottom. Wade (22238) |
| I had some slop in
my crossfeed screw when I took it apart and cleaned it up. I was
able to take some of it out by playing around with placing arbor
washers just behind the handle on the crossfeed screw. Arbor
washers come in various thicknesses much like shim stock and I had a
package of assorted thickness from McMaster-Carr. I was able to
eliminate a lot of backlash. I know this is not a permanent
solution, but as the washers wear, I can always add more. Mark
(22239) |
| Wade, A crude fix
would be, go to McMaster and get 99044A523 brass acme coupling nut,
left hand thread for $29. Drill and tap a mounting hole in the side
and shim it in place. Or braze a piece of flat stock to the side and
drill and tap the whole assembly. This nut is 2 inches long and is
class 2G, sloppy but better than what you presently have. JP (22241) |
| Cross Feed
play |
| I have a 10K and
have too much play in the cross feed. I can push and pull the
compound back and forth after setting the desired depth . I can't
tighten the gibs too much when cutting threads therefore I would
like to know how to tighten the crossfeed assembly. I have a new
crossfeed nut installed so it isn't that. There seems to be a gap
between the crossfeed "bushing" (as labeled in the SB HTRAL book)
and the Cross-Feed Graduated collar. My question is: How do I remove
this collar/Bushing assembly to tighten to reduce play if indeed
that solves the problem or is there something else I need to do to
remove the excessive play. Wayne
(22398) |
| There was a
jpg of SB instructions on how to do this. Without looking at the
parts diagram, this is what I recall. You need to take the crossfeed
screw assembly completely out. Take the nut off the end of the
handle and pull the handle off. Watch for the key! The graduated
dial should slip off. There should be a short brass plunger under
the screw that holds the dial in place. I don't recall if you have
to take the bushing out or not. you'll need a pin spanner wrench or
something similar to screw it out if you do. On the handle end of
the crossfeed screw there is a shoulder that the handle butts up
against. According to the SB document you turn that shoulder back an
appropriate amount. You measured how much slack you had before
disassembly didn't you? You'll need a lathe to turn the shoulder
back. You could use yours if you tighten up the gibs to hold
everything tight and use the compound screw to feed in the tool. If
you lock the carriage and set the compound at 90 degrees you can
even use it to measure how much you are taking off. That's what I
recall of SB's instruction but I think there is an easier and less
risky way. Measure how much slack you you need to take up and put a
washer type shim on the inside of the bushing. That should take up
the slack. Note that the nut that holds the handle on MUST be
tightened until the handle buts up against the shoulder on the
feedscrew, it is not used to adjust for slack. All that said, lots
of people, including myself just put up with the slack. Once the
tool is contacting the work all the slack is taken up anyway. It is
a little disconcerting though with interrupted cuts to see the
compound moving back and forth. John (22400) |
| Just because you
have a new cross-feed nut doesn't mean your cross-feed screw is like
new. Unless the threads are good a new nut isn't worth much. (22402) |
| Wayne, You can
remove the nut (with a 'forked' screwdriver), remove the graduated
collar and shim behind it to take out the excess movement there. You
say you replaced the crossfeed nut, but how much wear is there in
the crossfeed screw? If you hold the crossfeed handle in against the
graduated collar and then grab the tool post and shove it in and
out, if there is any movement, and the nut is firmly attached to the
saddle, that is an indication that there is clearance between the
threads of the crossfeed nut and screw. Mario (22403) |
| Mario et al, I removed the cross feed screw added a
.007 washer/shim between the graduated collar and bushing which
reduced any noticeable play. I did the same with the compound
and improved it also. Wayne
(22423) |
| Price of
Crossfeed screw? |
| I am
dealing with a guy on a tailstock, compound, and base for a SBL
16"He says that the crossfeed screw is in pretty good shape, and
mine is badly worn. He wants me to make him an offer on the screw,
and the dial, and the handle. (Mine has the wrong one on it) I was
wondering how much it is worth?
(23339) |
I paid 400 for one
NOS from a guy for a heavy 10 about 3 years ago I understand they
are over 800 from LeBlond but that's just what I have heard but I
know they are UP there. A good used one should be worth at least 150
I would think but your the buyer so if he is parting out a machine
why not offer him fifty bucks in reality probably a good deal for
you and him. Grumpy
(23340) |
| I'm not going to
venture a guess on that one, but you might want to contact Plaza
Machinery, (they're online - somewhere). I just bought a new
crossfeed screw and nut for a heavy 10 with a taper attachment. Very
good quality, about $200 for the two.(23346) |
| I priced the
assembly from Rose and LeBlond. The compound cross feed assembly
which is the screw, nut, feed handle and a larger graduated collar
ran just under $600.00 for a 9A with the taper attachment. There are
several sizes of cross feed screws so be sure your getting the right
one. (23347) |
| Last time I priced
a Crossfeed Screw and Nut for a 13" from Rose when she was still at
South Bend I believe Regular Screw, Jam Nuts On End and Crossfeed
Nut With Retaining Bolt $1400. Hardened Screw, Jam Nuts On End and
Crossfeed Nut With Retaining Bolt $1775. $200 would be a steal.
Ended up buying Acme Rod and pinning to old screw and making nut at
work with their $200 Acme Tap. Cost $20. Results 12/20/04
(23348) |
| Ed, Your parts
and check arrived this afternoon. I have to finish up a grinding job
for Precitech. I hope to get to your job right after New Years. I
may get started before ,depends on what my wife has in store for me
. The honey doos. Their prices are scary. Aren't they? They want more
for their parts than you pay for a whole machine. Bruce (23353) |
| Darn, that must
mean the nuts cost $1,575. Seriously, check with Plaza. I didn't see
any cross feed screws listed for non-taper or for the compound, but
the one for the taper attachment was excellent quality. Greg (23355) |
| Has anybody tried
this outfit?
http://www.millermachineandfabrication.com/products.htm
Looks very reasonable. Roy(23390) |
| They did some gear
repairs for me (replacing broken teeth) and the work was excellent.
It was also cheaper than I expected. Paul (23397) |
| Got a few of those
honey doo's myself. :) was going to mention that you were taking
care of my backlash problem for me but didn't know if you wanted the
advertising or not. Sure looks like there is a market for you
skills. Ed (23413) |
| Crossfeed slop
measurement? |
| I have
been reading about .003 and so on measurements of play in cross
feeds. My 16" has about 3/4 of a turn of play. How are you guys
getting the measurements? I am NOT a machinist. I just bought the old
lathe a couple of years ago, and I'm kinda like the dog that caught
the car? Any help would be appreciated. I also would like any help on
books or manuals on how to use a lathe. I own a copy of How to run a
lathe, and it is good. I would like MORE! maybe a video?
(23370) |
| Mount dial
indicator on saddle with it touching the Crosslide base. Move
crosslide in just slightly (you are taking out any backlash ). Zero
indicator and Crossfeed Dial. Move Crossfeed in opposite direction
until Dial Indicator just starts to move (+ .001 ) Check and see how
much your crossfeed dial has moved. Subtract the .001 movement of
dial indicator from this figure and you now have the exact amount of
backlash in the Crossfeed Screw. Ron (23371) |
| You can stick a
feeler gage between the cross feed knob and the stem sticking out
from the cross slide. With the handle turned out towards
you. Bob (23374) |
| I purchased a video
that has some interesting old clips on it about running a lathe.
It's on a VCR and I'm set up to transfer VCR to DVD so if your
interested in a copy and are willing to pay for the media/shipping let
me know and I'll make some copies.(23395) |
| I got my
manual in, and I got brave; I took it apart. I found out it wasn't my
screw or nut that was worn. It is my bearings on the shaft pinned to
the screw. Either it has the wrong handle on it or the wrong nut
holding on the handle. I can't tighten up the handle enough to take
care of it. I put the nut on the screw and it fits VERY well. I know
with the handle on I can move it in and out about 1/8th of an inch.
Any suggestions. Also when I took off the dial and handle the
bearing had a thin piece of metal wrapped around it, like a shim??
the bearings both of them in and out have "nice 605" stamped on
them? Is that even the right ones? The nut for the crossfeed is made
of cast iron. I thought they were made of bronze? I forgot to tell you
it is a 16" SBL I think it is a 1944 model.157044 is on the
tailstock. (23621) |
| Slop In
Crossfeed and How To Correct It |
| Trucks 1956: I have
SB directions on how to fit replacement screws. Details how you
machine screw shoulders so handle fits correctly. I realize you are
not changing screw but procedure is the same if handle does not fit
properly on any screw be it old or new. I can scan and send to
you. Contact me off group if you would like me to send you this.
Ron (23625) |
| Ron, I would love
to see a copy of those instructions from SB and also whatever else
you might have in your stash of SB information. The taper attachment
fitting instructions that you sent were very informative. Some of
the that stuff didn't even cross my mind when I put on my used taper
attachment. In retrospect it was sheer luck that the thing works!
Roy (23627) |
| Ron, I have a 10L
that had some slop in the crossfeed. I took it apart and put a slim
washer behind the castellated nut on the end of the taper
attachment. It helped, but did not fix it. I took it apart again,
and put a thin washer at the end of the shoulder just before it goes
into the taper attachment. That snugged it up so that I had to back
off the castellated nut to allow the screw to turn. Now have the
same problem with the compound, but can't figure out how to get the
handle off. Both screws look pretty decent, with the shoulders of
the Acme thread square. Also, I noticed with the gib on the cross
slide loosened up that the screw appears to be slightly bent. I can
see the cross slide wandering back and forth. I tightened up the gib
and cannot see any weaving now by eye, but will put a dial indicator
on it this morning. Is that a problem? Brian (23641) |
| Cross feed nut |
| Does anybody know
the size of the acme cross fee nut on the heavy 10 Southbend. Is
there any place that it can be purchased or does it have to be made
special. Vinnie (23750) |
| 7 / 16 10 LH If my
memory serves me right. Grumpy (23755) |
| Cross Feed screws
and nuts can be purchased from Miller Machine and Fabrication. They
are listed in the links section, I think. (23757) |
| Cross Feed
Screw Nut |
| I have a
9in A with a taper att. the cross feed nut threads are worn almost
to points. I have a piece of aluminum bronze and bearing bronze.
What would be the better metal to make the nut from? And I was
looking in the FAQ for the removable of a direct reading collar, but
could not find it, could someone direct me to the right area to
look. John
(23845) |
| We use the
Aluminum Bronze for nuts at work. Very tough (wears little )
but also very difficult to machine. Ron (23848) |
| SB9 Power
Cross Feed |
| What is the power crossfeed useful for? I can't figure out a useful
purpose. (23881) |
| Facing off the end
of a shaft or truing up a faceplate among many others. Roy (23882) |
| Power feed helps to
generate a nice smooth cut because of a constant speed, much better
than you can do manually. JP(23883) |
| Use the
lathe for awhile and see if you can find any need. Once you grow
tired of facing by hand the use becomes apparent. I did a couple
dozen tubes. 3/4 ID 1-1/4 OD, 5/8 long from solid Alum. I cut 2"
parts from solid on the saw, faced, center drilled and then moved to
the drill press for punching the large hole. while I was drilling, I
was sawing. Once I had a few drilled, I could do a bore, saw and
drill. The bore and saw on feeds and me on the drill press. Made the
job go faster. Dave
(23884) |
| It is useful to
make a clean, square "facing" cut on the workpiece, especially of a
large diameter. I was facing off a 5 1/2" cast iron faceplate
yesterday and it takes almost ten minutes of careful hand-cranking
to make that work well. With a power crossfeed (which I have
coming!!) I could have watched the machine do it!! (sort of)
Bernie(23885) |
| You will find that
a much faster and smoother job of parting off can be done under
power, plus the tool doesn't suffer as much. Jim (23886) |
| One thing for sure,
it keeps the burns down on your hands from the hot chips. My lead
screw was down for a week or so and i had parts to make so I had to
hand feed everything. Ended up with a glove on my left hand due to
hot chips. Boy you sure don't know what you have until you have to
do without. I face a lot of 4" aluminum bar stock, it would be a pain
in the butt without the power feed. Bob
(23887) |
| Worn crossfeed
screw |
| Maybe someone can explain a simple
concept to me: the crossfeed screw threads on my 1936 9" lathe are
about 1/3 worn away and I'm considering turning a new one; I
understand this is considered a "precision" screw and I'm wondering
how much more precise it would be than one that is turned on a
ordinary lathe (like I'm thinking of doing). Rick
(24026) |
| "Precision"
is a term usually used when talking machine screws and nuts that
signifies either the process used to make them, which usually
involves grinding of the thread on the screw, or is sometimes used
to signify the fit or backlash between the screw and nut which is
sometimes no more than tenths of a thousand of an inch. Ron (24027) |
| Screw
dimensions are categorized by class, 2A, 3A etc. Look in the
Machinery Handbook or go to www.engineersedge.com for a full
explanation of screw class. JP (24028) |
| Slop in
crossfeed screw |
| Any recommendations for curing
slop in cross-feed adjustment screw, currently 1/2 turn of handle
on my 13" SB?
(25788) |
| Check
the threads in the holding nut the lost comes from there a you can
screw in the top flat screw on the cross feed it will help a little but
2 to 4 thousand of an inch if so. I have 25 thousands of an inch and to
sove it I will have to make an other part the thread is 10-3/8 acme
left hand check to make sure to me it is one solution or to buy the nut
that grabs the cross feed. Robert (25791) |
| You are talking
about a non-problem. It had a lot of slop in it when it was brand
new. To provide a screw with no backlash is possible, but requires
more than just a screw. Some of the old Cincinnati Milling machines
provided that in the table of some of their milling machines so you
could climb cut easily, but if it became out of adjustment at all,
it was worse than not having it, and making the adjustment required
removing the table. With any lathe, milling machine, or jig bore,
anything with a screw that holds your position you must be aware of
the direction you are working and in a short time it will be habit.
When you are turning the OD of the part, you always go to a right
hand reading and it will be accurate. The other factors for accuracy
are whether your tool is on center and if you are using a center in
the tailstock, is the tailstock on center. When you bore a part you
want a left hand reading and when you want to move away from the cut
after a pass, you can easily tell by the feel how far you need to go
to the right to move away from the cut. Bring your tool back out,
and move the slide back to the left to the last cut you made so you
know where you were when you decide what your next cut will be. The
best addition you can make to your lathe is a long reach dial
indicator, a 2 inch is fine. The indicator can be bought
inexpensively and by making a nice mount to read the travel of the
infeed on the infeed slide, it will be much easier to go back to
your location and can work more accurately. It really takes the work
out of the whole process. Some of the expensive lathes had this
feature built in. One was the American Lathe, as well as some of the
LeBlonds and Monarchs, all "high end" lathes. You don't need to
"gold plate" your lathe to make some nice improvements on it. A
collet set is nice, depending upon the work you are doing. Bill (25795) |
| Bill Thanks for
expressing this so clearly. I and others have tried for years but
most new comers seem to get offended when we tell them it is a
normal and natural thing to have backlash in feed screws on manual
machines. JWE (25796) |
| Bill
Could you tell me the thread size and pitch on the cross feed
Please . Ex. 3/8 10 acme LH. Robert (25797) |
| As Bill has already
pointed out, all screws (except ballscrews) have slop or backlash,
there are methods using a second nut to minimize it, not eliminate
it. However, there are still things you should check, is the screw
holding the acme nut tight? My cross slide nut needed 1 1/2 turns to
snug it up and the compound didn't have a retaining screw at all...
Are the nuts holding the dials firm? Have you adjusted the gibs?
Bernard R (25806) |
| Have you
checked the fit of the cross feed screw shaft to the collar in the
saddle? Often, in-and-out play of the shaft in the collar and dial
are mistaken for slop in the fit between the nut and the screw. The
thrust surfaces between the shaft, the collar and the dial wear and
in some cases, the whole shaft will have to make half a turn or more
to move enough to take-up the slack before the cross slide will
start to move (when changing from cranking in to out on the cross
feed). Webb (25810) |
