| T-slotted Cross Slide
(Feb 16, 2001) |
T-slot cross slide? (Dec 27, 2002) |
| 10K cross slide assy.
(Apr 14, 2001) |
9"
Cross Slide Slop Diagnosis Help (Mar 28, 2003) |
| Cross Slide Repair (May 5, 2001) |
New
Cross-Slide Threaded Rod (Apr 22, 2003) |
| Screw size for Top Slide
(Oct 3, 2001) |
Play in SBL9B cross slide (May 23, 2003) |
| Crosslide sleeve
(Nov 17, 2001) |
Set
screw above dove tail in crosslide (Jun 20, 2003) |
| Worn
cross slide on saddle of Heavy 10 (Dec 2, 2001) |
Rocking crosslides (Jun 27, 2003) |
| Cross slide nut? (Jan 8,
2002) |
Difference between crosslide feed screws (Jul 3, 2003) |
| Refurbishing a worn cross slide
(Jan 25, 2002) |
Tee slot cross slide table
(Jul 5, 2003) |
| Cross slide nut (Jan 22,
2002) |
Mounting holes in cross slide
(Sep 13, 2003) |
| Heavy 10 Cross Slide Thread
Pitch (Jan 28, 2002) |
Crosslide nut and screw 1/2
-10 LH acme (Nov 4, 2003) |
| Replacing Cross/Top Slide
Handle Nuts (Jan 30, 2002) |
Crosslide wanders (Jan
23, 2004) |
| Hole In Cross Slide (Jan
31, 2002) |
My heavy 10 cross slide?
(Apr 5, 2004) |
| Unknown hole on SB9 cross slide
(Apr 28, 2002) |
What are these holes for?
(cross-slide) (Jun 5, 2004) |
| T-slot crosslides (Jun
16, 2002) |
Finished T-slot cross slide
(Jun 8, 2004) |
| Light 10 crosslide screw
(Jul 1, 2002) |
MLA cross slide and faceplate
(Dec 21, 2004) |
| Heavy 10 cross slide
(Aug 3, 2002) |
Crosslide screw/nut repair
(Dec 24, 2004) |
| Ball handle threads on cross
slide (Oct 4, 2002) |
Slotted crosslide or
production saddle? (Jan 27, 2005) |
| SB
9 Cross Slide 7/16 X 10 Acme Nut Misery (Nov 6, 2002) |
16" SB cross slide screw
(Mar 8, 2005) |
| |
| T-slotted Cross Slide |
| Has any of you have purchased a t-slotted cross slide from Metal
Lathe Accessories? The place has a lot of kits that have been cast
by them and just need finished up by the buyer. Does anyone know of
the quality, and just how much finishing is required? I've really
been considering this, as I feel this would be a nice addition to
the South Bend 9". Frank (217) |
| I've been considering one
also. My problem is that I have no mill, so I'd have to get one
machined somehow. It would be a great accessory, though, for those
of use who have no milling machine. I've been thinking about making
just a cross slide plate with a bunch of taped holes, and If I made
it out of aluminum, I could probably make it on my own. More of a
boring jig, since it would probably not be set up to slide freely on
the dovetails. Just adjust it and clamp it down. Paul R.
(218) |
| I am in the process of machining a couple of the kits
from metal lathe accessories. so far I am very happy with the kits
and supplied reference materials. the guy's name is Andy Lofquist.
he is not online to my knowledge. He seems to be a really stand up
guy and very knowledgeable. I am a novice machinist, so I asked him a
lot of questions before I ordered. I ordered drawings first, and
then the cross slide, a milling base and the transfer block. ups
destroyed the package and 'lost' the cross slide so I have not seen
it yet. Andy has been very good about getting me a replacement for
it. It should be here soon, I'll post to the list how it turned out.
There is a guy who machines the cross slides, he is listed in the
website and in the literature. he quoted me a price of like $179 for
the slide machined and shipped with the new gib and screws. I wanted
to machine mine myself. Honestly, its not a bad deal considering
that the tooling will cost you nearly $100 alone (dovetail cutter,
t-slot and countersink). you really need it to make most of the
other things. I am paranoid and want to fit mine to my machine so i
plan on making it. Andy seemed to be low on stock after the cabin
fever show, but he says that new castings are on their way. he
doesn't actually cast them himself, he has a foundry cast the parts
for him. In addition to the kits I already got, I want to get the
milling base and maybe the faceplate. The two castings I did get
were pretty good. actually, they are the only castings and virgin
cast iron I have worked with, so I don't have much to compare to.
They are clean, they were a lot cleaner than I expected. no foundry
dirt or sprues or excess flash. They machine like cast iron, really
nice with sharp tools. they seem to be cast of a good cast alloy
material. So far, I have only milled the transfer block. i am
fortunate to know someone with a Bridgeport with all the right
tooling and attachments. I spent 6 hours making it, of which 4 I
think was jigging and clamping and changing tools. A dro was an
extra bonus. It saved me from counting turns etc and with a bit of
prep work, little to no layout. the drawings and instructions that
come with the kit are very good. remember they are drawings and are
not meant to be to scale. Drawing dimensions are 3 3/8" x 3 3/8" x
8". my finished block was 3 1/2 x 3 5/8 x 8. i left it big so I
could refinish it again, and to a regular (1/8" increment) size. the
slots were flashed over, so I ended up cleaned them up with an
endmilling operation at the end. The 2 sides that are solid are
meant to be drilled to suit: I drilled and tapped 3 rows of holes at
1 5/8" centers to match the slot and hole layout on the cross slide.
I think it will work out pretty good. the milling base is
essentially
the front half of the cross slide. The center hole accepts the dovetail'd spud on the compound. I have only surfaced it so far. i
intend to use it on the rear of the slide with a future milling
attachment or my toolpost. Since it will need the same operations to
finish as the slide I am waiting to machine them both. i would
recommend the milling base as a fixture to use with the cross slide
that way you can mount your compound and/or toolpost to the rear of
the slide so you can do thinks like turn left hand threads in forward
gear. While the 5/16 stud size is standard, i had some trouble
finding decent t-slot nuts and clamps. I ended up going with a name
brand kit for everything. in the end it ended up costing a bit more
than cheap imports, but they are worth the price. I think that you
need to think about the other things you will need to work with the
cross slide like t-slot nuts and studs to utilize it well. dennis
(219) |
| I have the T-slotted Cross Slide and
have been very satisfied with it. It is a good project but you'll
first need the transferor block to machine it. this can be a
Catch-22 situation since you also need the T-slotted Cross Slide to
machine transfer block. unless of course you have a milling machine
available to you. be aware that the T-slotted Cross Slide is prone
to band slightly when you tighten down on it. this makes it
difficult to move you will have loosened the gibs to use it
otherwise it is very useful. my suggestion if you do not have a
milling machine available to you is to have it made for you this is
what I did.. or if you have plans to buy a milling machine later you
might want to wait a put your money there instead. I find milling
machine is much more useful to me although I still use the T-slotted
Cross Slide occasionally. Rick
(221) |
| Andy Lofquist does
have a website, and it's quite good. Check out
http://statecollegecentral.com/metallathe/
for all of his stuff. I met him at Cabin Fever this year and he
seems like a very nice guy. The consensus on the Usenet metalworking
group is that his castings are superb. Sure liked everything I saw.
Now all I need is about $1,000! Charles (249) |
| 10K cross slide
assy. |
| My
lathe was apparently damaged at some point in time, and repaired by
some well meaning individual who either didn't know how or didn't
have the resources to do it properly. Perhaps they weren't so well
meaning after all. It is a 10K model A without the taper attachment,
and according to the parts list there appear to be some missing
pieces in the area of the crossfeed bushing. There are supposed to
be (2) three-piece thrust bearings, there are only 1 and 1/3. Also
absent is the Oilite bearing that should go between the rear thrust
bearing and the feed bushing. And it would appear from the parts
list that what is known as the C.F. (crossfeed) sleeve is supposed
to be pinned to the crossfeed screw itself. Is this correct? How is
the sleeve supposed to locate along the axis of the screw? There is
no pin, and no hole for it in the screw. Is there supposed to be a
way to adjust the play or load on the thrust bearings, or is it
fixed by pinning the sleeve to the screw? I speculate that the
machine somehow tipped over on its face, or something heavy feel on
it, and the outer end of this assembly was damaged. I submit a bent
crossfeed ball crank and apron handwheel, and a broken and
weld-repaired compound as evidence of this. Whoever attempted to fix
the machine did so without buying any new parts, and just did the
best they could with what was leftover. I've got it put together so
it's "useable", but it's not right. I'm having trouble maintaining
repeatability on diameters.
(519) |
| Contact
Meridian Machinery www.mermac.com or call 631-777-1317. He has
used parts and a very vast knowledge. The owner Dave Ficken is a
very patient man and has helped me with my search for parts.
Jim (520) |
| Here are
some instructions that will help with your cross feed bushing and
bearing fitting problems. These are actually for the "Heavy Ten"
lathe but the process is the same for the nine inch and 10K lathes
with large dials (1 3/4"). The Sleeve is supposed to be pinned. The
oilite bearing was used on later models. Earlier models didn't have
them (they relied on the bushing only). My parts breakdown only
lists one oilite (bronze) sleeve bearing and it is to be located at
the ball crank end of the bushing. If you need one, you can make one
from a standard oil-impregnated bronze bearing, 5/16 ID x 7/16 OD x
1 1/2"Long and reboring the ID out to 3/8". The thrust bearings can
be bought from any good bearing supply house. I used INA (a
manufacture) Bearing No: FT 010. Webb (521) |
| Cross Slide
Repair |
| The lathe is back
together! Check the project description at
http://pages.cthome.net/errol.groff/south_bend_cross_slide_screw_repair.htm
Errol (594) |
| Errol, I will eventually be making a
replacement cross lead screw and nut for my 9". It is very helpful
to see another's ideas. Question: What factors may you opt for a
commercial rod and nut instead of machining your own? Paul
R. (595) |
| Paul: You ask a
good question. What is it that makes us choose to do it ourselves or
to have is done. Our usual motto at school is "What do we have more
of, time or money?" Most always the answer is time But is this case
I really needed to get the machine back in operation so I decided to
go this route. Now that I have prototyped it out I will assign one
or two of my students to follow up with the parts for the next two
most needy lathes. Keep in mind that most of the work on this one
was done during school April vacation when I didn't have the
responsibility of minding students. It is difficult to do machining
when you have to keep an eye on 12 or 13 kids. Without getting way
off on a tangent about kids today not a lot of them have the "stick
to it" attitude that is necessary to develop a project like this. If
a student has to remake a part they will probably throw up their
hands and walk away from a task. Pretty much the only "club" an
instructor has these days is a grade and way too many kids don't
care about their grades. I realize that I am painting with a broad
brush and I DO have some students that I can rely on to do their
very best on what ever I assign them but there are too many projects
and not enough of the good kids to do them in a timely fashion. (596) |
| Errol Makes
a lot of sense. Now if you were going to make one from scratch, what
kind of steel would you use, and any particular kind of brass? I'm
obviously asking with the intent of making my own replacement parts.
There's an article I have in HSM or MW (can't remember which) that
addresses some of this, but I don't know if it mentioned type of
steel/brass. Paul R. (597) |
| Paul, I did exactly
this project on my 10k. Having had NO experience cutting threads it
took me much longer than it would today. But it was a blast!! I used
12L14 for the screw. That went so well I ended up redoing the tail
stock screw and the compound too. :) I bought the cross slide nut
from Southbend, about 55.00. That looked to be a bit more than I was
prepared to take on at the time. My lathe has the power cross slide.
I didn't make the "power drive end". (btw South Bend wanted 645.00
to make this part). I did make the threaded portion. The over all
length about 1 inches longer than the original. Cut off the old one
just shy of the old threads, leaving the stub as long as possible.
Bored a hole in one end of the new screw to match the stub length
and diameter. Then silver soldered the two together. What a
difference!! The tail stock quill threads were a bit worn. I wasn't
feeling up to making a new quill yet (no taper attachment) so made a
new feed screw that fits the quill threads as they are. Works great.
Did the same for the compound screw. Ray
(598) |
| Screw size for
Top Slide |
| My 40's era SBL 9
has 12-28 setscrews for the Gib. I have not found a source for these
and was thinking of maybe drilling the holes and retapping 1/4-28.
There is not a lot of metal there but it seems like such a small
change. The question for those with more recent lathes, is South
Bend still using the 12-28 screws or did they go to something else?
(1700) |
| I'd resist the
temptation to do that unless necessary. Are they that rare? Tried
specialist fastener suppliers? Want me to look?(1701) |
| I would hate to see
you do what you suggest because you can't find 12-28 set screws.
Here is a place that has 2200 of them in stock
http://www.iinc.com/barber/inventss.html
Yasmiin (1702) |
| You might check
with Fastenal http://www.fastenal.com , we have a local store here
in Waco, TX and they seem to have a lot of specialty items. Lew
(1707) |
| No, Yasmin
sent me a link to a stainless set screw supplier
that has lots of sizes. I am a little surprised that the big houses
like McMaster-Carr and MSC don't have these sizes - even if they
aren't used that much anymore. Bill (1721) |
| This may have been done
to keep them in place. That just adds to the motivation to single
point them. Make your blank the same diam as the existing screws, if
you have any to measure. The tricky part is cutting the slot, one of
those little hacksaws that looks like a cheese cutter helps. I think
I made mine with a die but I started with a blank the size of the
other screws. This screw is not a fastener, its a translation
screw, and can be expected to be odd. RC (1722) |
| As far as cutting
the screw slot, they do make some files for this. I guess you could
use a thin hacksaw. Use your finger (thumb) nail as an initial guide.
Just let the saw blade or file rub against your finger nail. It
won't bite. The files I am talking about have the cutting teeth on
the edge only. As I remember they come in two widths. I think .062
and .032 approx. Brownells should sell these. Don't put a lot of
pressure on them as they will break. Let the file do its work. Tom
(1723) |
| Why not buy a
slotting saw (cheap!) and do it properly? What's a "translation
screw"? (1726) |
| Crosslide
sleeve |
| Does the sleeve in
which the cross slide screw runs on the 9" SB lathe unscrew from the
saddle casting the way it does on the larger lathes? The 13" lathe
has hex flats on the sleeve where it enters the casting to make the
method of disassembly very obvious, but the little one does not. My
clever stepper motor mount (clamps around the end of this sleeve
just behind the micrometer collar) blocks the slide from retracting
the final, badly needed 2 inches. Since I'm making a new screw
assembly anyway, I am tempted to try to replace the sleeve with a
longer one, so that I can obtain the full designed range of travel
even with the stepper mounted. Failing that perhaps I'll try to
redesign it with just a hose clamp band instead of the current bored
block of aluminum with a tightening screw across a slot.
Chris (2189) |
| The
bushing (what you call a sleeve) is RH threaded into the saddle.
Sometime you will encounter these with a small hole (drilled in the
periphery at 6 o'clock radially) for a pin wrench to act upon. One
way to unscrew the bushing, if you have removed the saddle from the
lathe, is to strip out the ball crank handle, dial, and screw and
then grip the bushing in a vise that has its jaws well padded (with
lead or leather). Then the saddle can be unscrewed from the bushing
without marring the bushing. Webb (2190) |
| I think I
may have found a way to make a new clamping motor mount that does
not completely encircle the boss leaving the top clear, which would
avoid having to make a longer bushing. But if I do need to take it
out, I'll just make up some copper pads for the 3-jaw and tighten it
down on the bushing, then use it as a wrench to unscrew. Or I might
use my old motor mount as the wrench. Chris (2191) |
| Chris, If you
are going to use the chuck mounted to a threaded spindle, you will
with all probability just unthread the chuck. Plus the clamping
pressure needed might spring the jaws enough to impair the accuracy
of your chuck. I understand that you are trying to get a good grip
on the bushing to unthread it. If you had a collet big enough, well
maybe. But the lathe is a precision instrument and should be treated
with respect and care. Damage or your accuracy may suffer if you
don't. I don't intend to chastise; but I do think using a well
padded vise is the way to go. Or drill a shallow hole in the bottom
of the bushing and use a pin wrench. Webb
(2192) |
| Chuck would not be
on the lathe, rather the part I'm trying to unscrew from the
carriage is. But I don't think I'll need to take it off now. Chris
(2193) |
| Worn cross
slide on saddle of Heavy 10 |
| I have been
using and restoring a Heavy 10 (vintage 1941). The cross slide of
the saddle is worn in the middle, such that: If I tighten the gib so
that it is snug in the middle, it is too tight to travel to either
end of the range; conversely, if I loosen it enough so that it can
travel across the entire range, it is very loose in the middle.
Because I have a Bridgeport mill, I am planning on remachining the
dovetail ways of the saddle in the following manner: 1) Let the
saddle rest on a pair of cylindrical rods of the mill, indicated
carefully for height and parallelism; 2) Using a 60-degree dovetail
cutter, take off just enough of the casting to expose fresh metal
from the cross slide. 3) Add a shim to the crosslide gib as needed.
My question is, does anyone have experience and advice for me in
doing this? Also, I have heard of putting in Teflon or "Rulon"
strips to the gibs, for better sliding action. I don't know anything
about doing this. Jon (2306) |
| Don't take this
wrong as I mean well. Don't take the mill to your cross slide as you
will ruin it. It needs to be either reground or re-scraped. Look for
someone that can do that for you. The mill isn't accurate enough to
do a cross slide on a lathe and you would be doing a great
disservice to the person that buys the lathe. Yasmiin (2307) |
| Cross slide
nut? |
| 9"/10K cross
slide. How does the cross slide nut get attached to the slide. I
have a slotted set screw and the slot is gobbered. I am afraid to
wrench too hard. Is it left hand or right hand? non-taper style nut
(flat topped). (2601) |
| I am
assuming that you have a 9" or 10K lathe with a non-taper type cross
slide. The "set screw" in the center of the cross slide nut retains
the nut in the cross slide casting. the casting has to be removed
from the saddle before you can remove the nut. After the casting
with the nut is removed from the saddle, loosen the "set screw" and
twist the nut back and forth while pulling the nut out. The "set
screw" has a conical point and as the screw is tightened down, the
wedging action of the conical point bears against another part
(called a "pin" by SBL) and pushes it out perpendicular to the set
screw and this forces the pin out against the inside of the hole
bored in the cross slide casting; locking the nut in place. Webb
(2630) |
| It's
the set screw that's gobbered up pretty good, and I am afraid that
the slot will shear out causing me to resort to e-z-outs. Is the set
screw right hand or left hand thread? I am thinking I only have one
shot to get it out. dp (2631) |
| The set
screw is right hand threaded. I don't know the thread size off the
top of my head. But remember it is a standard fine thread. Webb
(2633) |
| I think I did it
good. plenty of liquid wrench and the slot of the screw is shot. I
think its ez-out time. the screw is right hand? could someone try to
remove theirs? while you are at it, measure the threading too? I
would appreciate it. dennis (2753) |
| Dennis, I have
had mine apart. Actually I made new bronze crosslide nuts for both
my lathes. They are right hand threads. I think it was 1/4 x 18 or
at least some standard thread. I borrowed a tap from work to make
the threads. Glen (2754) |
| The LEADSCREW nut
is 18TPI? Mine is 3/8-10 acme if memory serves. Sorry I tuned into the middle for this thread, what am I
missing? (2755) |
| He's referring to the retaining
set-screw in the top of the cross-feed nut. Paul R. (2757) |
| I think it was 1/4
On a cross or compound slide I think a thread is used that makes the
dials come out even to 1/1000 or a good even fraction. I have seen
25 tpi (same as a micrometer) or 20 tpi (the cross slide on my old 6
inch Atlas. My new HF minimill has 16 tpi and the strangest dials
ever seen to get that odd .065 inch included. I would rather have
metric as a hand held calculator can convert that if they could not
make a reasonable thread on the slides. The Smithy that took up room
in my shop for a short time had dials that were marked as
approximate
.049/ division. What good is an approximate division value? John
(2788) |
| I was talking about
the set screw for the cross slide nut not the thread for the nut
itself. Glen (2795) |
| Refurbishing a
worn cross slide |
| I have an old Heavy
10 (made in 1941), that had a very badly worn cross slide. The
saddle casting was worn so much in the middle that it was impossible
to properly adjust the gib. If I tightened it so that it would be
snug in the middle if its travel range, then it would be too tight
to travel to the extremes. The dovetail ways had been worn to an
hourglass shape, and the flats had been badly scored and scooped in
the middle. Some of you with older lathes may have experienced this
problem. I have heard from a machinist that this is a very common
problem. I have remachined, sanded, and scraped the cross slide
ways, and took photos of the process to share with this group. The
photos are attached: 1. I set up the saddle casting on a Bridgeport
vertical mill. The vee ways of the saddle rest on a pair of 3/4"
rods. The rod on the right hand side sits on a piece of aluminum
with a vee machined out of it. This is supposed to keep the saddle
aligned properly so that the remachined surfaces will be
perpendicular to the vee ways. The rod on the left hand side rests
on a flat piece of aluminum, milled to the height that will make the
saddle level. The saddle is clamped down with two pieces of wood. To
avoid flexing of the saddle casting, I didn't want to exert undue
pressure. 2. The saddle is checked for alignment with a dial
indicator. Both the dovetail ways and the flats are indicated in. 3.
I machined the surfaces with a HSS dovetail cutter, at a speed of
150 rpm and a table feed rate of about 1inch per minute. (2796) |
| After machining the
saddle casting, I did a similar process to the compound rest base,
and checked for squareness back on the lathe bed. Attachment:
(image/jpeg) 4.checking squareness on lathe.JPG (2797) |
| (continued from
last message) sorry about that. The picture captions got left out
from the previous post: 4. A 6-inch parallel is held in the 4-jaw
chuck, and a dial indicator is used to check for squareness with
respect to the spindle (the chuck must be rotated by a half turn to
verify that the parallel bar is in correctly). 5. This is a home
made scraping tool that uses a TPGH-322 carbide insert. This is good
for making light finishing cuts on the flats of the ways, and also
for scraping under the dovetail ways. 6. The relief angle of the
TPGH insert allows the carbide to scrape while its face is
perpendicular to the machined surfaces. I found it necessary to use
one hand to press the shaft of the tool against the dovetail
surface, so that it would bite into the cast iron.
****************************************************************************
Here are the captions for the last set of photos, which are attached
to this post: 7. After sanding off the machining marks and a few
iterations of scraping, I flaked the flat surfaces of the saddle,
using the "bump" method. This is supposed to make it look as though
the saddle was refurbished by an experienced professional, rather
than a novice like me... 8. The compound rest base was remachined
and sanded in a comparable manner to the saddle. Only one side of
the dovetail was remachined, since the gib protects the other side
from wear. For setup in the mill, the gib was held in place by
magnets, and the gib surface was indicated in. The photo also shows
a brass shim I made to compensate for material removed by wear and
machining. The trough (surface in the photo where the gib rests)
also had to be milled to compensate for removed material. 9.
Checking for final alignment, with saddle reinstalled on apron,
complete with taper attachment and cross feed screw. I stopped
scraping once the indicator showed less than +/- 0.0005" variation
over the cross slide travel range. I am satisfied with how this
project has turned out. The lathe works much better than before. Jon
(2800) |
| Cross slide nut |
| How
many people are interested in 'new' cross slide nuts? I am going to
talk to a friend who works at a company that makes thread mills to
see if I can swap him some time on the CNC tools. (they make the
coolest thread mills. they have a widget to show how good there
tools are: they have a nut that works on both left handed AND and
right handed threads. I do not lie, I have witnessed it.) I would
like to collaborate with others in the group to get some sort of
'improved' design over the stock nut. it would be nice if we can
figure out a way to make them simply backlash adjustable. I was
thinking ala Bridgeport style, but that might be too complicated.
Otherwise, I am thinking plain simple basic nuts and bosses. I am
thinking or running a bunch of 'rough' machined parts: 1" square
stock that will be cross drilled and acme tapped. The boss turned
oversize. final turning of the diameter and drilling and tapping the
setscrew hole and 'pin' hole is up to the user. Costs: cheap.
Depends mostly on material selection. the CNC time would be free
(may lunch and a twelve pack) and packaging and postage. Any one
interested? collaborators? we could even make compound nuts too.
Dennis (2863) |
| I bet everyone, but
WHICH one are you going to make. I have a heavy 10. I also need a
GOOD cross slide screw for a taper attachment. (2864) |
| I'd sure like to
know how to make it backlash-adjustable. Can you explain how the nut
on a Bridgeport works? (2866) |
| Marty: what are the specs on
the nut you need? I have never taken a part a heavy 10. lets make a
list of what we want and see how many different parts we come up
with. Then I can go in educated like and not waste a lot of time in
the shop. What about making them adjustable? we threw it around a
while ago. The Bridgeport x-y nuts are a bit complex, they are
barrels with a slot cut 3/4 through in the middle. Adjuster screws
on the housing flex the nut to take up the backlash. If we can come
up with a simple modification to the nuts, I think we could make
something serviceable. dennis
(2867) |
| Dennis, That's a
wonderful idea. Count me in. If we could just produce, like you say,
a piece of rectangular brass/bronze bar stock with an offset ACME
threaded hole and leave the finishing up to the individual, that
would be great. If there's enough "meat" left, that would give us
options for designing the backlash compensation mechanism. I've got
a few designs we can kick around. What size does the compound use?
I'm sure my lathe needs a replacement compound-feed nut too. A
replacement cross-slide lead screw is something the lathe-owner can
machine with minimal tooling, but the nut has been (at least for me)
a "tough nut to crack". Let's do it. I'll buy some beer ;-) What can
we do to get started on this? Who knows of a good source for the
stock, and what material should it be? I'll put together some of the
nut designs I've seen and we can critique them. Paul R.(2868) |
| It seems
I must chime in and correct some misunderstood things about cross
slide feed nuts and the screws that work with them. First the taper
and standard cross slides do not use the same nut. The nut for the
taper slide is flat on top without the locating boss the standard
one has. The feed screws from SB come as an assembly with all
related parts such as handle, dial, mounting bush and feed nut along
with the screw. If you look at the catalog page you will see that
when you order it, it is an assembly number and all the parts marked
* come with it as well as the feed nut. Next when using the taper
attachment you remove the screw that connects the feed nut to the
cross slide and all of your diameter adjustments are made with the
compound feed as the cross feed is disconnected. Finally thread
milling on this thread will be very difficult if not impossible
because of the thread size and pitch involved. I have a quote out
for a tap right now and they all have told me that with this thread
a tandem tap is not possible as it would be to weak and break.
Measure it out like I did and note that there is not sufficient room
for a 10 pitch acme thread cutting tool to pass through the core of
the thread. If you can not thread cut an internal thread you can not
mill it either which means using a tap. Acme 3/8-10 taps are
available but because of the coarse pitch and small diameter a
combination tap is not possible. It will require two taps, a
roughing one and a finishing one. I am trying to get a quote on them
right now and will let all know the price when I know. I am also
including two small articles on backlash adjustment from ME in the
60s by Geometer so that this process can be better understood by
all. JWE (2869) |
| James, Thanks for
the articles from ME. What you said about the details for cross feed
screws and nuts may be true for SB's 9-inch lathes, but I don't
think it is the same for their Heavy 10's. The parts list for the
Heavy 10 is different. See attachments. My suggestion for doing
taper turning with a short screw was to unscrew part #16 in the
diagram (C.F. BUSHING), because it is easier to do that than unscrew
the cross feed nut. (The C.F. nut is labeled as part number 55 in
the sketch, but listed as #50 in the table. It looks like SB made a
couple of typo errors for that page). With the longer screw, normal
taper turning is done by disconnecting the rear hex nut, item #16 in
the sketch. These are my observations of the two old Heavy 10 lathes
that I have. On one of them, it appears that a previous owner
switched out a short screw for the original long 2-piece taper
attachment screw. Jon (2871) |
| Jon The 9", 10K and
10L are all similar while the heavy 10 is a completely different
breed of cat. I hope all realize that fact and do not try to mix and
match parts between them. It is like when I got my bed turret in the
late 70s, someone had put a spacer plate on the bottom of it to use
on a 12 or 13 inch machine. The dealer had it sitting around for
years and when I expressed interest in it the joy on face at some one
wanting to buy it made him very generous in the way he priced it.
The same as for the follower rest I got last month on Ebay, I knew
from the pictures it was for a 9" or 10K but because it was not
listed that way I got it for about 1/3rd what they normally go for.
What any of us say can only apply to the machine we have experience
with and all comments and suggestions need to be referred to the
catalog parts list for the machine in question or the newbie with out
experience will be very quickly confused. JWE (2872) |
| I believe that the
Heavy 10 is the same thing as the 10L. The 10K is sometimes called a
Light 10. The original post about cross feed dials and taper
attachment was for a 10L. That is why I replied with info for a
Heavy 10. (2873) |
| I have followed the
postings about the differences between the light 10, 10K and Heavy
10/10L machines. I have found that the easiest way to keep them
straight is that the Light 10/10k machines are simply 10" versions
of the time honored 9" machine. Southbend started making them back
in the late 60s or early 70's, as I remember. The 10k has the
spindle size of the 9", so is limited to using the 3C collets, where
as the Heavy 10 has the larger spindle that take the 5C collets. I
have found that some small parts do interchange, as I had a 9" when
I first purchased the Heavy 10. I have been tempted to bid some 10"
parts on e-bay for my Heavy 10 and always need to clarify with the
seller just what he is selling, (which many times is not the case).
Hope that this helps. Keith (2874) |
| Jon What I have
seen and worked with myself have been 9" and 10K 3MT spindle 1-1/2-8
thread uses 3C collets 10L 4MT and I think 1-7/8-8 spindle uses 4C
collets Heavy 10 5 MT spindle 2-1/4-8 or D1 spindle uses 5C collets
The 9" and 10K share almost all parts and are very hard to tell
apart. The 10L is a in between machine that shares some features of
the 10K with a larger spindle. The heavy 10 is more similar to the
larger machines in size and design. JWE (2875) |
| The 10K or Light 10
can use either the 3C collets with the taper sleeve adapter or the
6K collets (direct fit no taper sleeve needed). The 3C have about a
1/2 max capacity and the 6K have a 5/8 max. capacity. The 10K
spindle has a large ID chamfer and a (drive) pin that permits the
use of the 6K collets. SB 9's use the 3C collets only with the use
of a sleeve adapter. Tom (2876) |
| James et all: this
is exactly the process I was hoping to go with the group. I think
this Endeavour is best described as a group project. there are many
members out there who have more knowledge than I do. I just have an
idea and maybe the access to the tools that would make the Endeavour
reasonable and economical. we we can work together then we all
benefit. i hope that we can discuss what has to be considered and
collectively find the solutions. I think that we are on the right
track. in fact it sounds like there are going to be 4 solutions:
9"/10K taper cross slide and non-tapered slide, and then the same
for the 10L. as far as threadmilling, I have confirmed that they can
in fact treadmill the 3/8-10 LH acme. Its not going to be the usual
treadmill however, and it might take a bit of work to fine tune,
but that's for me and my friend to work out. I am willing to take the
time and effort to try it. at this point, what we need to
collectively do is identify the size and pitch of the threading of
the different ones we want to make and then 'design' the nuts. I am
happy to draw and detail the nuts on CAD. If anyone out there has a
head start then great, we can use that too. I am not looking to mass
produce a bunch of finished parts, but make the nut in a sort of kit
form for list members finish and to better their machines. I look
forward to the groups replies. dennis
(2877) |
| My new MSC catalog
[which is at work, and I'm at home as I write this] has some Acme
taps that look like 2 taps joined end-to-end...the front part makes
a 60-degree thread form it looks like, and the back part makes that
into an Acme, each tooth is a little closer to an Acme and a little
less like a V than the last. Is this what they call a 'tandem
tap'? (2878) |
| Well, here's my
idea: make the nut in 2 pieces, joined in the middle by a thread
larger than 7/16-10 Acme but very fine, I dunno exactly what, like
say 9/16-32? Sort of like the threads in the middle of those little
stainless canisters like my Grandpa had his nitro pills in, it
unscrewed right in the middle. You unscrew the two halves of the nut
apart to take up endplay; each half only wears on one face of the
thread. Hmm, big enough joining thread may not fit under the cross
slide. How about make it in two pieces with the top stud on the one
piece and both pieces having little ears sticking out to the sides,
one's ears threaded for about a 10-32 capscrew and the others having
clearance holes for same; you screw the capscrews in to draw the two
halves of the nut together to take up endplay. Again each half only
wears on one face of the thread but it isn't worn out until the
threads are completely, totally gone. What do you guys think? (2880) |
| Brian It sounds
like yours is either a later machine or a different model. If it is
.430 that would be 7/16 and thus larger than mine and different than
the other two 9" machines I have worked with. The two PDF I sent
earlier today from work showed several different methods for doing
adjustable nuts for taking up slack. What will probably work is some
combination of what is shown in the two of them. I will really need
to take my machine more apart and see how much room is there to work
with. As far as fitting things up the feed screw is the least part
of the problem. The nut is going to be the most work and effort to
get right. Every tap maker tells me that 3/8-10 in a Acme tap is not
doable unless we go to the low profile form. 7/16-10 will probably
be achievable. The question is if those with 3/8 feed screws would
want to go to 7/16 or even to 1/2 inch. In that case a 10 tpi Acme
tap will be fairly easy to get made at a more reasonable price. From
the price breaks for the 10x1.0 mm taps I got before for the 7x
group the best break came at 50 taps. So to get a good price we will
need to decide on what size to go with and if there will be enough
that want one to get the price down. The same will hold true for the
chap that can thread mill nuts he will need a common size to get his
setup and material cost down to a reasonable level. If we do this
the question now is what size do we want to do the thread in?
JWE (2883) |
| Brian, This is a
tandem tap. The 60 deg front part is to rough out the bulk of the
material and the rear acme form then shaves the final acme form. I
purchased one from www.Tapsdirect.com prior to christmas for my half nut
rebuild. The cost was about $105... the best price I could find. I
did pick up a thread about an acme plug tap for $35 from MSC.
However, I was told that the tandem produces a much better finish.
From using the tandem I also would say the plug will tap much
harder. Ed
(2884) |
| Dunno WHAT I have
here. SBL tells me it's an "R" from the S/N but nothing on it
matches my old book reprint [book #17-L] for an "R". I think this is
a "Workshop" lathe which is in book 19-C which I don't have. It is a
horizontal drive "C" with the motor drum switch mounted where the QC
box would go, manual change gears, a single-neck idler banjo, non-detented
[bolt-lock] tumbler and 6:1 compound gears with a 118T screw gear.
SBL sent me the original card for the lathe 3 s/n's ahead of mine,
and that one was shipped to Brazil in '37. The large-dial
replacement carriage I snagged fits; it is marked "S102" and "J130"
under the cross slide, and the underside of the cross slide is
marked "J130". This is the one with the homemade dial bushing,
crosspinned small CF bushing and trashed leadscrew with ball thrust
bearings. The original carriage is marked "52" under the cross slide
and has small dials. The CF screw for the large-dial one is 10TPI,
.439 OD over the unworn part of the thread. I haven't disassembled
the original small-dial carriage to measure, but the leadscrew looks
the same OD to my eye. Remember mine is a pre-fire lathe; I'm told
that is somehow significant. None of these numbers match either of
my books. Maybe someone on the list can shed some light. I suspect
my large-dial carriage may actually be a 10L or 10K carriage. I
dunno. They're both no-taper-attachment. (2886) |
| James et all: as
far as costs for the setup and making the proper thread mill and
making of the parts, there is no issue there. as he and I will be
making them after hours on a weekend. i.e.: no overhead if you
understand my meaning. The only real costs at this point will be the
materials cost. i am willing to float a length of sae bronze or
brass. I am going to go scavenging too to see if anything can be
had. my friend was going to check to see what masters were
inventory. they have 2500-3000 thread masters in stock. he thinks
that they might even have one already made! the process is really
neat. They custom make their own diamond grinding wheels for the
carbide and grind the profiles on the inserts and solid tools. The
master grinding wheels are all kept in this huge room that reminds
me of a old data storage center or film archive. I shouldn't say
much more, I don't know what is trade secret. What we need to do
next is 2 part. 1. determine the geometries of the basic stock nuts
that we need to make. Which means that for each type of slide and
machine size, someone has to make a drawing of the part. I suggest
that we make sketches of the stock assemblies and the go from there
with modifications. I think it also be prudent that we note any
markings on the nuts that we are measuring and maybe the cross slide
unit code numbers that are stamped on the casting. 2. come up with
the clearances and geometries that we have to work around as
constraints to design an adjustable nut. I have attached a sketch of
the nut that I have which came off of my 10K as an example. I will
measure the side and bottom clearance later. I used cad since I have
use of it. you don't have to use it. hand sketches that can be
scanned are fine. you can also fax them to me if you need. I will be
happy to redraw them in cad. SOMEONE PLEASE CHECK MY WORK! i have
not yet removed the cross slide screw, and I am measuring a REALLY
worn out nut. so worn in fact that the threads look like they have
serrations. the side of my nut appears to have the letters "N 11"
stamped on the side. I will remove it later this week. you are
correct in your assumption that we need to figure out how much
clearance we have to work with to make adjustable nuts fit. i would
also suggest that we consider how they will be adjusted. It might be
wise to use some sort of hex head screw that would be adjustable
from the rear of the cross slide with a long Allen wrench. so to
those following the thread, some one with a 9"/10K please verify my
sketch. Someone else who has their machine apart please sketch and
post the other nut styles. please include any part number marking so
we can classify the nuts. We will need: 9"/10K taper cross slide nut
heavy 10 std. cross slide nut heavy 10 taper cross slide nut someone
was after a compound nut (marty?) how about a sketch of that? any
other sizes of lathes out there? c'mon guys there are like 400 or so
of us here. someone else must need/want a new nut or two. I look
forward to your responses. Dennis (2887) |
| A workshop C has no
worm and worm wheel or clutch in the apron, power feed is via
closing the halfnuts, manual change gears. My Workshop C has the
single arm banjo, it is S/N 61150. It also has the 118 tooth screw
gear and locking bolt style tumbler. There is some question whether
this lathe is from 1936 or 1939. I haven't called SB to see what
they say, I just never think of it during daylight! Perhaps all or
some of your parts were swapped between several lathes or onto a new
bed if the S/N doesn't match up with the rest of the parts.
Stan (2888) |
| Denis: I think that
you have a great idea here, and I am very interested.( read "very"
with large flashing bright letters!!) If you used a large enough
profile stock and offset the thread as you indicated I suspect that
you would only need two sizes to accommodate 9/10k or 10L lathes. I
am going out to my shop a little later in the morning and will try
to confirm the dimensions off my very worn non-taper 9"A model. I
was wondering if it might be appropriate to also locate a supplier
of LH acme precision threaded rod, and have the nuts sized to fit.
There have been several recent articles on repairing feed screws
using stock rod. I know that my lathe needs both screw and nut, so
it might be worthwhile to at least make the info available. FWIW, I
recently made a 1/2x 10 RH acme tap to replace the down feed nut on
my Atlas shaper. I used the dimensions from "Machinery's Handbook".
The tap is a little ugly but it made a serviceable ( much better than
what I had) nut. It wasn't too hard, but I don't work to the
tolerances that most of the members might want. Pete (2890) |
| Got called away
from my computer; dunno if my previous post posted or not. Your
lathe sounds just like mine, which is s/n 75045 and was made in
1937...so yours was probably made in '36. The large-dial carriage I
bought separately later. There is another parts book, #19-C, I need
to acquire I guess. (2892) |
| Denis: I measured
my 9" A model c-feed nut, and found a couple of minor differences on
the dimensions 1) length of nut is 1.165" 2) max width of body is
.710" 3) length of stem is .860" This might be accounted for because
it looks like the nut was machined from a bronze casting. If the new
nut was made based on a block of material 1"x1 1/2'x1 1/4" the end
user could machine to the dimensions of what they have.
Pete (2894) |
| I am interested in
how you made your acme tap. How did you relieve it and what metal
used and hardning method. I have some other machines requiring nuts
and don't want to spend a fortune in new taps. I bought a cross
slide assembly (SB 13") that was in great shape but the nut was
shot. Decided to go whole hog and purchased from MSC a length of LH
acme thread ( other site threads imply precision threads hard to
find and probably pricy). I made a whole new front end including the
gear section and pined on the MSC thread. Also ordered a LH tap and
used it for finish cut of a block of bronze after I lathe rough cut
the start. I used the old nut and the new nut on a piece of new acme
screw fixtured in my BP mill and indicated the sides in order to OD
turn with a boring tool the stem OD to the correct centerline. It
fitted nicely the first go and outside of the cost of the pricy tap
was a good deal and is now working nicely in my late model SB 13
with a 7' bed. This worked fine for me because the slides were not
worn too much. I expect if the slides were redone a correction in the
centerline of thread to round top might have to be made. Probably
something a person buying an original SB nut might run into. Walt
(2895) |
| There was a short
article several years ago in either the Home Shop Machinist or
Projects in metal that showed a tricky way to make an adjustable
cross slide nut. As I recall it made one part of the two part nut
threaded on the outside one or two more threads per inch than the
lead screw. This part was screwed into a mating receptacle on the
cross slide frame. This exterior threaded part was turned in or out
a little to adjust the back lash. I will try to thumb through my
stack of past issues and find it. Someone else may remember the
article and have quicker access to it. Dallas (2907) |
| I think that the
self-compensating leadscrew nut that you are thinking of is like the
one found at this link.
http://www.kerkmotion.com/Pages/axial%20take%20up.html
Take a look at their other anti-backlash solutions. There are some
good products here. I have not yet attempted to make these out of
brass or bronze yet, but it seems like a great idea. Keith (2965) |
| I found the article
in Projects in Metal April 1998 titled "An adjustable cross slide
nut" that I remembered seeng. It describes a method of making a
cross slide nut that can be adjusted to zero backlash. The scheme is
to bore 1/2 of the existing acme thread out larger, and thread this
larger bore to 9tpi LH vee thread. A short sleeve is then made
threaded both on the outside and inside. The outside is threaded to
9tpi LH vee to mate with the nut body. The inside is threaded 10tpi
LH to run on the lead screw. The sleeve is castleated on a thin
flange on one end of the sleeve. This allows the sleeve portion to
adjusted to zero backlash and locked in place using the slots in the
flange. As wear occurs another notch can be taken up on the
adjustable sleeve. Dallas (3050) |
| I
wanted to update all those interested in the cross slide nut
adventures....i am having success in making the parts. it will be a
couple of weeks or more to go. 1. I have decided to start by making
plain simple, similar to factory nuts. 2. we successfully
thread-milled test holes of both 3/8" and 7/16"-10 LH acme.
I
checked the 7/16 against the screw that I have removed from my
machine. as my nut was so worn, it is like night and day. my screw
is worn in spots, so I do have a bit of play, how much i won't know
until I finish making the nuts. it is acceptable. 3. the process of
making the nuts: a. we are turning down round stock, 932 bronze
(replacement to SAE 660). b. chucking the bar stock in a CNC lathe
with a bar feeder. c. turning the boss to a shoulder and then
dressing the big end of the nut. Final od on the boss I am leaving
at 0.688, which is 1 thou over. reasoning: I don't trust the
measurements of my cross slide nut hole as exact. I think people can
easily fit the nut to their cross slide with a bit of emery papering
from here. d. then we are center drilling and chamfering the pilot
hole for the set screw. the set screw in my nut is not 1/4-28 as we
thought by 5/16-24. i am making all to 5/16-24. next we cut off the
part and caught it in the thing i can remember the name of. Its a
chuck that spins at the same rpm as the stock chuck and grips the
part before it is fully cut off. e. move over to a old hurco mill
and then cross drilling the pin hole and an index hole to jig the
nut for thread milling. i ended up deburring the part at this stage.
f. the moving to a machining center, we are chuck the nuts in a CNC
5-C collet indexer and spot facing a couple of flats for the pilot
hole for the acme thread. g. threadmilling the acme thread. h.
optional: roughing out the profile of the nut taperer body. Since
the piece is chucked and in the mill, I can rough it out. users can
finish from here. 4. hangups: we did not have a the proper/ a good
collet to chuck in the indexer on the machining center, so the blank
wasn't held tight in the collet. End result was that the pilot hole
and threading was not exactly 90 to the boss. By turning the boss to
a given collet dimension, we could produce exact results. I am
ordering a few collets this week to try and get a better grip on
things. I am getting a few emergency collets too so I can make the
right one if stock ones don't hold right. comments: I am amazed at
how nicely the bronze is finishing. Lots of coolant, SHARP carbides,
and precise feed rates. leaves me a bit to be desired on my manual
lathe work. Repeatability always amazed me. programming the tools
took less time than I thought. Realistically, it took 30 minutes to
write the code, and another 10 to tweak the program with tool
offsets. Need to bump the tool a quarter thou? no problem. Just push
a few buttons... viola! cylce time: after we got things going, it
takes 3 minutes to turn the blank and cut it off. about 5 minutes to
clamp, drill and remove the blank. It took almost 4 minutes to bore
and thread. I spent more time walking from machine to machine. Only
regret aside from not having the proper collet is that in the lathe,
the gripping chuck when it catches the cut blank mars the finish a
bit. It leaves a scuff mark. it is certainly a cosmetic flaw. I
don't think that anyone will complain that the mirror finish on the
boss is a necessary feature. next steps: once I get the collets I
will be able to finish. I will send out 5 nuts to 'beta-testers' for
review and comment. if the nuts pass inspection, then I will send
them out to those interested. Cost: materials and other consumables
is just under $6/nut. I am replacing the end mills and drills and
taps that I am using at the shop. for now the treadmill is free. I
figure that at the end, another $4-$5 for a box and shipping will
bring the total up to the $10 range. I am not charging for my time.
future projects: compound nut: I have not yet taken apart my
compound to get at the nut. I haven't figured out how to. I will do
it, but in the meantime, can someone, ANYONE PLEASE confirm that it
is 3/8-10 LH acme? that should be a simpler part to make. Backlash
adjustable nut: I think I have figured out a simple mechanism to
adjust backlash. It involves a bit more machining work. I will draw
it up and post it to the list for review and comment before
entertaining that endeavor. Undersize nuts: since I do have a worn
screw, I am going to try to make a nut or two under spec to see how
it works to take up play. Not sure if this will work, what I really
need is a treadmill with a profile that is not symmetric so I get
fatter valleys and thinner valleys to compensate for the worn screw.
For now, progress. Slow but sure. I will try to take pictures of
what I have and post them to the list. dennis
(3155) |
| Excellent news
Dennis. Your efforts are appreciated and on behalf of those of us
many thanks. Keep us posted on your progress. Hope you still have me
down for one! (As I mentioned in a previous email. Its ok for me at
least to do the final work, the threading is the tough part). Marty
(3160) |
| What I meant to say
is that to properly make a nut that will compensate for a worn screw
thread is the threads on the nut need to be 'tighter:' wider threads
and the valleys a bit narrower. to do that I think that it needs a
custom grind on the cutter. undersize nuts: since I do have a worn
screw, I am going to try to make a nut or two under spec to see how
it works to take up play. not sure if this will work, what I really
need is a treadmill with a profile that is not symmetric so I get
fatter valleys and thinner valleys to compensate for the worn screw.
(3161) |
| A
few people have emailed me to ask what the status is on the nuts.
the status is i am at the mercy of paying work to get more machine
time. the machines have been tied up on a couple of large runs and
we did not want to tear down and re-set up the fixtures. those jobs
should be finished up this week and hopefully i will be able to get
in on Sunday. thanks for you patience dennis
(3528) |
| IIRC, a while ago
someone on this list was working on making some replacement cross
slide "nuts". Is this true? Who do I contact about this? I had my
crosslide apart recently and the wear on the nut was amazing. I can
hardly believe the thing works. Jeridiah (4283) |
| Dennis Pantazis is
who you need to talk to. I was lucky enough to get the very first
nut from him about three weeks ago. I didn't get it installed until
last night. I was busy (My son is now two weeks old! ... And the
concrete for my workshop was poured this morning). My old 1928 9"
Jr. lathe is a bit different than the 9" Workshop lathes, and I had
to mill the nut down to match the original height, drill and tap the
retaining hole deeper, but it fits wonderfully. When I bought the
lathe there was about .085" (almost a full turn) of slop in the
crosslide. I replaced some of the worn washers on the screw
assembly and took out .035" of play, leaving me "only" half a turn
of slop. After installing the new nut, the play is under .003"! It
feels like a new machine. -Mike (4299) |
| Yes, I am the guy
with the cross slide nuts. I have made the first batch, sent them
out to the beta testers. I have gotten positive feedback from a few
people, haven't heard anything from others, and i am still waiting
for some to send me $$$. if those who have dibs and have not sent me
monies, then I will put them on to the open market next week. in my
case I went from about 0.090" of backlash (yes, almost a full turn)
to about about 0.007 mostly due to screw worn at the worst place. I
have been meaning to take some pictures to post, but have not had
the time. Maybe over the weekend. Future batches to come, just don't
know when. dennis
(4308) |
| Dennis, What model
did you make the nuts for? I have a 10k with taper attachment. How
did you cut the threads? My nut is LH 7/16 x 10 and the cheapest I
can find a tap is $179. If I make the nut can you tap it?
Jay (4313) |
| May I suggest you
contact Tracy Tools of Dartmouth, South Devon, UK phone No her in
the UK is 01803 833134 fax 834588 I have in the past bough left hand
taps from them for lead screws for about say 16 dollars US at our
shows here and that even if post a packing cost more cant come near
your price. Phil
(4315) |
| Here's the report on my 1941 9" model A cross-slide nut replacement.
After finally completing the machining of my 5" and 6" replacement
chuck back-plates, and squeezing in a few minutes this morning, I
have a wonderful new cross-slide nut installed on my SB. I had to
remove about a thousandth off the boss diameter, a couple of thou'
off the top and ream the cross-pin hole to 0.250 to fit my old
dowel. I still have about .007" play in the thread (MUCH BETTER),
and plenty more in the bushing, but what do you expect of a 60+ year
old lead screw. When I get around to fixing the bushing, I think I
can live with the old girl. Many thanks to Dennis on a fantastic
job! Any thoughts on doing a compound nut? Paul R. (4317) |
| I
put a picture of the cross slide nuts in the photos section. the two
on left is finished regular style nut. As you can see, its finished
nut. Finished nut includes new 5/16-16 set-scew. 'puck' on the right
is for taper style nut (as I still don't have a taper style nut to
go from), or a blank for those who want to roll their own. Both
types have the 7/16-10LH acme thread milled. dennis (4323) |
| I have a
Southbend Fourteen with a taper attachment and I was wondering if
you can make some cross slide nuts that would fit my lathe. The
manual lists the part as a Cross Feed Nut, 5/8 - 8 Acme L.H and the
Compound Rest Nut, English Thread, 1/2 - 10, Acme R.H. Please let me
know if it possible for you to fabricate these nuts, if not, I will
give it a go on my own and would appreciate any help.
Ray (4338) |
| Would you like
some money for a nut for a South Bend 9" lathe? I can also trade you
a beta set of brass jaws that fit steady rests for the 9", 10K and
10L lathe. South Bend wanted $35 per jaw, I'll trade you 3 for 1
nut. Ted (4433) |
| Heavy 10 Cross
Slide Thread Pitch |
| Off hand does
anyone know for certain what the lead and size is of the crosslide
screw for the Heavy 10? (Later model double tumbler). Marty (2966) |
| On mine, (old,
1940's model Heavy 10, single tumbler) the diameter is 7/16" and the
pitch is 10 tpi left handed. You can be sure the pitch is 10 tpi
when the dial has 200 graduations of .001" (indirect reading), or
100 graduations of .001"(direct reading). If the dial has 250 or 125
graduations, then its pitch is probably 8 tpi. In general, you can
correlate the pitch with the dial markings in this way [i.e., 1
inch/(8 revolutions) = 0.125" per revolution]. On the parts list
from South Bend, they do not distinguish between newer vs. older
models for the cross feed nut, so I believe yours should be the same
as mine. Jon(2980) |
| Replacing
Cross/Top Slide Handle Nuts |
| So now that we know
how to get the bushing out, how do we get it to stay in? There
doesn't appear to be a setscrew or anything for locking it in, and
I'm a little hesitant to loctite it for fear the loctite will get in
between the bushing and the leadscrew...when I back out the
leadscrew the bushing backs off. (2996) |
| On both of
my SBs it is threaded in, you just install it tight. If the threads
are weak for some reason, you could use low strength loctite, but I
haven't had to do this on either of mine. You can always wrap the
bushing in brass shimstock and grab the shimstock with medium
channel locks to get a better grip, although a few gentle taps on a
closely fitted pin dropped in the provided spanner hole is probably
adequate - its worked for me so far. I wish they had provided flats
on this part for the 9 inch lathes, as they did on the 13, next time
I have it apart I may just mill flats to make tear down easier.
Either that or make the proper spanner. Stan (2997) |
| Hole In Cross
Slide |
Is the
hole you are referring to the one in the cross slide right above the
bushing for the cross feed? That hole in the cross slide (mentioned
in the posts about the pictures of Rick Kruger's lathe) is for the
Threading Stop. If you look in your How To Run A Lathe by South Bend
Lathe, you will see a picture of the threading stop and how it is
used. Webb (3013) |
| The hole I'm
referring to, is drilled from the top of the carriage; marked [on
oiling.jpg here on the server] as 'feed screws type oil C oil
daily'. I'm guessing you're referring to the one drilled
horizontally into the end of the movable part of the cross
slide?(3014) |
| Brian, Yes, you
are correct. That is what I was referring to. I think I was mislead
by the difference in terminology that people use to refer to
different parts of a lathe. To me, the Carriage is the total
assembly consisting of the compound, cross slide, saddle and apron.
The Cross Slide is the moveable casting which mates to the dovetail
of the saddle. And the Saddle is the casting that slides along the
bed. So, when you said "I notice the little oil hole in the top of
your cross slide at the front..." I though of it in my terminology
and misunderstood what you were indicating. To me, what you are
referring to would be the little hole in the top of the saddle. I
apologize for my misunderstanding. Webb
(3020) |
| No apology
necessary, just trying to keep the terms straight. it seems that
what SBL calls a part, many people have a different name for...for
example, SBL calls the casting a saddle, but many others use the
term to refer to a swaybacked form of bed wear. Lathes are truly a
subject where one pic is worth 10K words. (3021) |
| Unknown hole
on SB9 cross slide |
| Rick Kruger wrote: It is for the feed / screwcutting
interlock pin. With the half nut clamp handle taken out, the pin
slides across the big hole and out through the side of the apron,
through the hole you mention. This is the pin referred to during the
reassembly of the apron:
http://steammachine.com/hercus/page5.html
Can anybody tell me what the horizontal 3/16" blind threaded hole in
the end of the cross slide is for? Cheers Charlie
(4144) |
| Cross slide blind hole: Which end? The near/dial end? If so, is that
not the threading stop hole? I don't have one, never use one, but am gonna make one, now that I understand its operation. Takes one
thinking step out of the single point threading process. Rick K.
(4145) |
| Not Exactly, Rick.
And on my list too. It gets kind of dicey for me when I have to back
the cross-feed out more than one turn. Sometimes I loose track and
have to go back and verify. You tend to loose you rhythm then.
Paul R. (4147) |
| Rick Kruger wrote: Yes, its at the dial end, I
thought it was for an oil nipple but probing with a scriber showed
it didn't connect with the oil hole drilled down from the top.
Charlie (4153) |
| T-slot
crosslides |
| I was looking at
T-slot Crosslides at
http://www.sc-c.com/metallathe/index.html and
was kind of wondering if it would be possible to make the Atlas type
work on a SB, has anyone given this any thought? Matt (4627) |
| Matt, Thanks for
the WEB site I haven't been there since I got my 9A and I had
forgotten about it. Maybe I am missing something. If you go back to
the site the very first item on their list of products is a T-slot
crosslide for South Bend 9 and 10K. I don't know what you have so
I apologize if this is not new information to you. Jim (4641) |
| No problem, I go
and drool there quite often. I know they have a special Crosslide
that uses the SB compound, but I was thinking it would be handy to
have one that had T-slots all the way across, not to say that the SB
t-slotted crosslide wouldn't be nice to have also. Matt (4643) |
| Matt, Your question
about using the other cross-slide got me thinking that one of those
would be more useful to me than the one expressly for the 9" SB. I'd
rather have a boring table than some place to mount an inverted
cutoff tool. Looking at the dimensions, it looks like it would work
great. Good call! The other thing I was thinking of was just making
a fixed one (no leadscrew nut) out of aluminum for the occasional
line-boring operation. Paul R. (4644) |
| I have
a t-slot cross slide that I am interested to part with. I bought it
finished machined from MLA about 18 months ago. At this time I am
most interested in trading for some tooling for my SB 9A I am
looking for a steady rest and a follow rest for my lathe, or what
have you. I have placed a couple of pics in an album called t-slot
cross slide ( the only ones I have right now) The first one shows
the MLA cross slide next to its replacement, which is designed to fit
a taper attachment. The second pic shows the new cross slide mounted
on the lathe, before I finished all the machine work. I will post
some more information on this project if there is any interest, when
it is complete. Pete (4666) |
| G'day All, There
was a recent thread on T-slot cross slides. I found this one
available at the UK Lathe site:
http://www.lathes.co.uk/salespic/boxfordtslide/
Bill (4781) |
| Funny you should
mention that bill, cause I just tried to fit that exact cross slide
on my heavy 10" lathe. Wouldn't fit, darn. I had a flyer about 5
years ago that had one of those for sale as a rough casting. I have
considered machining one for myself, way down on the long list. Joe
V. (4786) |
| I have
just posted a picture of the T-slot cross slide that I have made for
my SB 9A. ( in the photo section under t-slot cross slide) It is
designed to accommodate the original SB taper attachment. Please
excuse the paint job, I plan to refinish my lathe in the near future
and I didn't want to waste the time on it now. ( now if I can only
figure out what the correct color is?) Pete (4789) |
| Beautiful Job Pete,
where did you get the iron? I would love to make one of those for my
10". Do you have any drawings? Did you use a tapered Gib or set
screw type straight gib? Joe V. (4791) |
| Light 10
crosslide screw |
| I have been slowly
cleaning the absolutely filthy 10K accidentally acquired at auction
(went to get Hardinge HLV-H, only came home with SB light 10 :^)).
Disassembling, parts wash, touch up fitting, reassembly,
re-alignment. Last night got to run it for the first time, though
taper attachment is still in the parts wash sink. It was obvious at
auction the crosslide screw had a good bit of wear. Disassembly
showed the screw and nut may last a few more years, but they are
sloppy (to say the least) and fading fast. While the lathe is back
together, I would like to make a new set. I _know_ it was
irresponsible, but was in such a hurry to try lathe out, I did not
mic it while apart. Also, could not get 3 ball handle off, and so
could not check dimensions and shoulders beyond screw area. I did
get the handle off the compound, so understand how it works, but the
crosslide handle was a bit more stubborn, and I decided to wait
until I could rebuild that component. So the question is: Is there a
site or archive to download prints or dimensions for a SB 10K, model
A gearbox, crosslide screw. Don't know if it matters, but this one
has the taper attachment style slide. Also, does anyone know what
material it was made of, and what would be a better material?
smt (4873) |
| There is a
difference in the nut for the taper models. What you might think
about is sleeving in a new section of ACME thread to repair your
crosslide lead screw. I can't remember the cost off hand. I think a
complete crosslide lead screw will sell for about $65 to $100
depending on condition. I think Plaza sells reconditioned ones for
about $100 and the nut for about $35. He also sells a section of
acme thread for I think $30. You might check the prices at McMaster-Carr etc. for lead screw material. Tom (4874) |
| I actually just
read about how I guy bought nuts and threaded rod and did this exact
repair and it worked great according to him!
http://pages.cthome.net/errol.groff/south_bend_cross_slide_screw_repair.htm
Tom
(4875) |
| Thanks for the information. Since the rest of the screw (all but
the threads) seems unworn, your suggestions to sleeve on only that
section sounds brilliant. I use Acme rod from MSC for other
applications, had forgotten they also have the precision stuff,
almost dirt cheap, for leadscrew apps. Looks like a 3ft section of
alloy steel acme 1/2-10 LH is 21.30, and the bronze nut is 19.09.
Best thing is the work (turn down section of acme to insert into
interference fit bore in remaining section of old cross slide screw)
can all be done in the split bed lathe with the SB apart. This
really makes the job look simple. Stephen (4900) |
| Heavy 10 cross
slide |
| The cross slide on
my well used heavy 10 has a lot of slop. I have tried the gib but it
only stops the movement at the extreme out position. Is my problem in
the cross slide nut or is there a way to take this out?
(5566) |
| Not clear on your
problem. If you can grab the cross slide and shove it forward or
yank it back a "substantial" amount, it is probably the nut and
screw. Check also that the collar on the micrometer stem that acts
as a thrust washer is adjusted to remove slop at the screw stem.
Check also that the screw that retains the leadscrew nut is snug.
Especially if you have a taper attachment and take the screw in and
out periodically. As far as mitigation therapy, the screw and nut
can be pretty far gone before you "have" to do anything about it.
Just always take your backlash out going the proper direction, which
is proper procedure anyway. If you are saying you can shake the
cross slide sideways, unless the gibs are so tight you can't
practically move it, then you will have to rescrape the dovetail
ways. smt (5568) |
| The type of slop
you are talking about is not clear but sounds like you definitely
need to shim the gib if you can bottom it out. A long .010" shim
between the gib and cross slide (not against the wear surface
obviously) will allow you to snug the gib which should fix most side
to side slop. A piece of discarded feeler gage is good for this. Try
to match the length of the shim to the length of the gib. Also
completely remove the gib and cross slide and thoroughly clean the
ways since there is likely much swarf in there causing problems. The
wear will probably be uneven so you have to compromise the gib
tightness to get your full range of travel. Backlash caused by worn
nut and screw is not really serious unless the screw is moving, or
screw is severely worn which could cause lead error. Joe
V. (5573) |
| My message was not clear and I apologize. Let me try
to describe the problem. When I grab my cross slide I can make it
move back and forth about 1/4 inch. I tried cranking it forward and
it holds but if I push it it will move forward and the reverse is
true when I crank it back. I 'm not positive what backlash is but I
have an idea. This is like the gib is not holding. I have a taper
attachment and there appears to be a few thousandths play between the
end of the feed screw and the end of the taper attachment sleeve but
not enough to cause this much movement. If it is the gib is there a
fix that doesn't mean making another gib? Strom
(5578) |
| I'm still not sure
in what direction the play is. If you can move the cross slide
toward or away from the headstock by any detectable amount (by just
pushing and pulling on it or on the compound), you have a gib issue.
The gibs just assure that the cross slide moves exactly
perpendicular to the turning axis, with little or no play. If the
play is crosswise to the turning axis, that is in the direction the
cross slide is supposed to move, I don't see how it can be the gibs.
It could be the nut, either due to wear or it's mounting. It could
be the bearing where the cross feed lead screw is anchored to the
cross feed. If things are moving 1/4" I expect you can look at
things move with the sheet metal chip guard out of the way and see
where the play is. If you can see what moves perhaps I can look at
the same place on my heavy 10 and tell you what is supposed to sit
still and what is supposed to move. Frank
(5581) |
| It's not the gibs.
It's the leadscrew/nut combination. As mentioned previously, check
that your collar is adjusted to remove any play where the stem comes
through the casting for the mic dial and handle. Also check that the
screw that holds the leadscrew nut in place is tight. After that,
all the slop is from a worn leadscrew and nut assembly. Mine (light
10) is not quite as bad as you describe. But I rebuild machinery
from time to time, including precision re-scraping, so it bothered
me enough to consider making new parts. (easy to do, we all have
lathes, don't we?) I got several pieces of good advice from this
list, including a link from Tom Jelly that describes a pretty easy
straight forward fix using prefab generic precision lead screw/nut
assemblies from the MSC Industrial catalog. Do a search of message
#4875, and click on the link Tom included for me. I found the parts
for my 10K (actually enough for several lead screws, though only one
nut) for under $50; and I have little doubt they are probably better
quality than SB stock. In the event, I have been living with the
slop. It is not a problem, if you have the gib adequately (_NOT_
overly) tight, and always use good practice in which way you end the
leadscrew motion for the work. Make all fine adjustments using the
compound. I do intend to rebuild the nut and screw as per the
article "eventually", but can't afford the down time right now. The
design of SB or most simple lathe nuts will not permit you to ever
eliminate all slop, this is the reason for good practice in the
direction you make you final move when setting the cross slide.
Always to take up the slack. A brand new assembly and well adjusted
collar may get you to within a few thousandths total backlash, but
it will still be there, and will bite you at sometime if your habits
are not good. smt (5582) |
| Strom This sounds
exactly the same as the problem I had with my Heavy 10 which was due
to some dingbat removing one of the thrust bearings from the
leadscrew mount in the taper turning attachment. Assuming that your
lathe is like mine, with the telescopic leadscrew, the cross slide
feedscrew is actually fixed in the taper attachment not to the
graduated collar handwheel assembly as is normal on most small
lathes. The feedscrew has a plain extension at the rear which passes
through the hollow rod onto which the upper binding lever clamps the
taper turning unit when taper turning. There is a thrust bearing at
each end of this rod with a nut and washer on the back end of the
feedscrew to lock everything up tight. I presume things should be
shimmed for nominal zero play. The handle spindle just turns the
feedscrew via sliding collar or splines (I've not looked) so when
taper turning the feedscrew can slide up and down on the handle
spindle. I solved my problem by making a solid spacer bearing
exactly the right thickness (near enough 1/4") from Glacier dry
bearing material which will do until I get the right part. The basic
movements are fairly stiff so it takes a good shove to actually move
the feedscrew in its mount so as to reveal the play due to a missing
bearing. On mine you could do an accurate job of turning dural with
normal feeds and cuts or a light feed, light cut job on mild steel
just relying on the stiffness to hold things in place. It wasn't
until everything went whahooie shape on a screw cutting job that I
discovered the problem. Clive (5626) |
| Ball handle
threads on cross slide |
| I removed the cross slide ball crank on
my 10K as the handle was broken and I wanted to measure it to make
or purchase a replacement. The parts list shows the handle as
removable from the ball crank but I couldn't get it off on the
machine. Anyway, the ball crank was stuck so I used a puller on
it...I knew it was a bit Neanderthal but I was only going to use
very little force on the puller. Anyway, I deformed the threads on
the lead screw end that the ball handle nut threads onto. I have a
couple questions: It appears that the threads are #12-24 is that
correct? I'm worried my measuring may be off because the threads are
deformed. The only small male thread I found in my "shop" was a
#10-24 and that was a very loose fit in the ball handle nut. So I'm
assuming the thread is a #12-24. I'm thinking of making a split
thread forming die by splitting a piece of mild steel then drilling
and tapping it on the split. I'll then assemble the split die from
the rear portion of the damaged threads and thread it on from the
undamaged rear side of the threads. My goal is not to cut new
threads, but since they deformed that easy, to "form" them back to
serviceable...does this sound good? (6566) |
| Been there, done
that (doh!!) I recently had the experience if repairing the threads
on my cross slide screw. ( please don't ask why!) I didn't have any
12/24 stuff so I cutoff the thread, drilled the end of the screw for
10/32 about 3/8 deep and loctited a 3/4 long set screw in. I them
made a new retaining nut with the new thread. Worked good! As to
your suggestion about the "repair" of the thread by backing off a
split nut, I have done this successfully many times when the thread
is slightly damaged. If you can obtain a high quality nut ( as
opposed to a cheapo hardware store one), split it with a fine saw,
gently smooth the cut line with a fine file and place both pieces on
the good threads. Hold the split nut in either a 6 point socket or
with vise grips, gently applied, and turn off the thread. you may
have to do this several times. Pete (6567) |
| I'll keep your set screw method in mind in case I
mangle the thing more trying to fix it! (6571) |
| SB 9 Cross
Slide 7/16 X 10 Acme Nut Misery |
| I have a SB
9" Model 409AN Serial # 73878 and the cross slide has too much front
to back backlash the gibs are fine with no left to right play. I
took the compound apart and the screw looks good, the nut looks like
cast iron, its not the color of bronze has a good 50 thousands slop.
I have looked in @ 8 catalogs and the web for a 7/16 x 10 Acme tap,
and can't find one. Does any body have a doable solution?
(7006) |
| There's some files
here on the group site pertaining to this...also check out
http://pages.cthome.net/errol.groff/
and scroll down to "South Bend Cross Slide Repair". Errol had the
same problem and an unwillingness to pay SBL [now LeBlond] prices
for new parts. On the same topic, has anyone ever tried Loctite
Form-A-Thread? I know the stuff was tough enough to hold the
swingarm pivot in my old Harley's frame for a couple years of hard
riding...but I don't know how it would stand up to the abrasion of
constant movement. Could a tap be fabricated from a short length of
acme rod? Could an Acme tooth cutter be ground from a tool blank,
then used to fab a tap? (7007) |
| The adjusting nut
on the compound my "mew" model A is missing and the threads are
damaged. I emailed South Bend and other than offering to sell me the
nut for $6 they weren't too helpful. Because the item is still
marketed they refused to give out the specifications for the thread.
From a quick measurement the thread looks to be 24 tpi. I think it
is 60 degree but didn't look at it really close. The ID seems to
fall between a #10 and a #12 screw thread. I haven't found any
standard that matches this measurement. If SB would have been more
helpful I would purchase the nut but I still have to repair the
thread. I can probably repair the thread with a file. I'll look into
the Form-A-Thread as I might be able to make a #12 nut work. Sound
reasonable or should I just bite my tongue and order the part? John
(7011) |
| There's a
now-obsolete standard, not even in current machinery's Handbooks,
under the old thread system, for 3/16-24...it's within a couple
thousandths of a 12-24, and it's the old American [pre-UNC/UNF]
60-degree threadform. I have a couple taps for this thread if you
need one. You aren't talking about the leadscrew then...what part
ARE you talking about? The thread in the TOP of the leadscrew nut?
or...? Yeah, I got the gearbox. Nice one too. I have another in not
as nice shape, pretty worn but still transmits power, I'll let got
for $125. Lurch (7015) |
| Lurch It is the nut
that holds the handle on the feedscrew. It also adjusts the endplay.
I think it is a little bigger than 3/16 (0.1875). A very quick
measurement on the OD gave m 0.215". Could it be 7/32 (0.219") I
didn't attempt to do a three wire measurement (not sure I know how).
I need everything that you got from Mr. Ed. Leadscrew, outboard end
leadscrew bearing, gear bracket mine even has the 42" bed!. I'm
chasing a gearbox and leadscrew on ebay right now, unfortunately
they are seperate items so I have to be careful about winning one
and not the other, so I can't bid to high. I think the bids close in
4-5 days so I can let you know about your gearbox next week. I've
never ran a lathe bigger than a Unimat DB200, so what could I expect
from your worn gearbox? John
(7017) |
| Email me offlist and we'll work something out as far as you 'hauling away
that old greasy junk' and paying for the privilege of hauling it
away chuckle need my parts washer for something other than storage
and the little lady off my a$$... I have an extra compound or two as
well...was going to use one for to build a milling attachment, but
the other we can deal on. Per Machinery's Handbook the major diameter
of a 12-24 is .2078-.2150. The minor diameter is .1710-.1810. There
is also a 1/4-24 thread w/MINOR diameter of .205-.215, which
although it sounds unusual, at least one tap for that bastard thread
is in every decent Harley mechanic's toolbox. (7019) |
| I am at a slight
loss here, I did not know that there was an adjustment screw?
Clint (7024) |
| John, The nut
doesn't adjust the endplay, you need to machine the bushing or the
end of the feedscrew to adjust the end play. There was a note from
SB on how to do it in the files section a while ago. I haven't
looked to see if it's still there. I have an extra "A" leadscrew for
a 42" lathe and right end support bracket if you or anyone else need
it. Glen (7025) |
| Glen Does that mean
that the nut is just tightened up tight? I'll go look for the
instructions now. John
(7026) |
| Are you talking
about the slotted nut that holds the crank knob on the end of the
leadscrew? (7027) |
Clint I've been
talking about the nut that retains the handle on the compound screw.
I assumed that this could be used to adjust backlash. According to
Glen R's post this is not the case and I will have to machine the
end of the screw itself. I haven't found the SB instructions Glen
mentioned so if someone could point me in the right direction, I'd
be forever grateful. John
(7028) |
| Yes (7029) |
| [total
backlash]=[play in leadscrew fit to leadscrew nut] + [endplay in
leadscrew-to-bushing]. Slop in the screw-to-nut fit is just plain
wear. Endplay slop in the leadscrew itself can be shimmed out. As to
causes of the latter I would look at thrust bearing wear
first. (7030) |
| This is what
happens when I start to compose a message from work and get
interrupted and someone else asks the question and it gets answered
before I finish and hit 'send'. No wise-apple-ness intended. (7031) |
| I found the
document I was talking about. It was actually related to end play in
cross slide lead screws, but should be applicable to compounds as
well. Check the attachment in this list posting:
http://groups.yahoo.com/group/southbendlathe/message/1824
Shims would probably work, too. The slotted screw on the crank
should be tight or else it keeps working itself loose. Glen
(7032) |
| Last week I posted
for source for 7/16 X 10 Acme treaded rod and tap. They were just
not to be found. My Cross Slide had about 3/32" forward and back
slop (not from ball crank). I had read about cutting off old thread
and press fitting a piece of 3/8 X 10 Acme rod and modify a stock
precision nut to fit. I inspected the old Acme rod and nut and found
that the rod looked really good and the nut was worn. I thought if I
could get a new nut, it would probably reduce the slop to usable
condition. No nuts to be found - a few maybe promises but no nuts. I
called LeBlond and a new nut was $40 + $7 for screw, they came in kit
form only, the threaded rod was over $700. I ordered a nut, it came,
it was a forged bronze piece with no 2 slides parallel, but the
threaded hole and the mounting hole were in line and at right
angles. I had to reduce by .060 the top surface to be inline with
the cross slide. All works fine and I have no slop in any direction
-- good as new (1937). LeBlond has a lot of parts, they are very
high, again I say very high priced but they have them. I saw a picture
of my nut in diagram, they said it wouldn't fit that mine should
have a vertical post but it didn't, I took my chances and only had
to take off .060 off the top. They also have a $10 order fee which
has nothing to do with shipping. I guess they are a last resort
parts source. (7163) |
| I think I posted
that Plaza sells ACME Rod and the nuts. The nuts cost about $35. I
think a foot section of ACME rod cost about the same. Still, I think
others have ordered ACME Rod material and some nuts from McMaster-Carr. The ones from Plaza are a direct replacement. Still, 40 +
shipping isn't too bad. Also, someone posted to check in the SB
board files. I looked in there last week. There is a link or an
article on this repair. Tom (7164) |
| T-slot cross
slide? |
| Anyone on this list
ever done the Metal Lathe [in Pennsylvania] casting for a t-slot
cross slide? I have a lathe, with faceplate, 3-jaw and 4-jaw, and I
am awaiting delivery on my Atlas horizontal mill...will I need a
vertical mill to machine this casting without undue stress [to me,
not the casting]? I'm thinking if I have a horizontal mill I can do
the top and bottom, and with an angle plate and some parallels the
sides and dovetails...I may have access to a vertical mill locally,
but prefer to be self-sufficient if I can. On a related note, I
saw a [supposedly OEM] "original SB milling table" on eBay for WAY
too much money--looked to me like just a piece of surface-ground 1"
flat stock about maybe 8" x 10" with a grid of tapped holes maybe
5/16-18 on about 1" centers, and a spigot on the bottom like on the
bottom of the compound. First I ever heard of such a thing...and I
wonder how well it would work? Anyone have any experience with this?
Did SBL ever make such a thing? Lurch
(8311) |
| I have done 2, one
from MLA casting, and another from one I had poured myself (with a
mod to fit a taper attachment) you will definitely need a mill, or a
shaper with at least a 12" stroke. you may be able to do it on the
Atlas with an angle plate. The MLA castings comes with the t-slots
cast in so you could get away with not machining those. To my
knowledge SB never made one, but it is standard on the Boxford
lathes made in England and is interchangeable with the SB. They can
be had used from G and M Tools www.gandmtools.co.uk for about
100ukp ( last time I checked) The cross slide can also be gotten
from MLA, finished. I have one of those, that I am thinking of
selling in the near future. I used it for about a year before I
built my own. Pete (8312) |
| Also see t-slot
cross slide in the photo section (8313) |
| Lurch, I finished
my MLA SB9 T-slot crosslide last fall. A very interesting project. I
started with a "well seasoned" preground casting from an estate
sale. Vertical mill and more surface grinding finished it up. I did
re-cut the T-slots. The dovetails were done with a dovetail cutter.
The drawing is not always a perfect match to the casting, so beware.
Andy has good stuff. RichD(8314) |
| Lurch, I did the
MLA milling attachment. I did all of the machining on my lathe
except the dovetails. The MLA instructions say to unscrew the
bushing from the cross slide to get the extra 1/2 inch of travel
needed to finish the cut in one go. I didn't feel too comfortable
with that, so I did it on the Bridgeport at work. I still have the
rough casting for the T-slot cross slide. When you start on yours we
can compare notes. I also have a cobalt dovetail cutter and T-slot
cutter. The dovetail cutter may need a little sharpening. Can
anybody offer advice on this? Glen
(8315) |
| Lurch, thanks for
reminding me. I have an MLA-5 milling attachment kit if anyone is
interested. It sells for $109.25 plus shipping from Metal lathe
Accessories.
http://www.statecollegecentral.com/metallathe/MLA-5.html
I'll sell it for $80 plus shipping. The castings are brand-new with
no machining done to them. My cat knocked a half-empty glass of
water onto the drawings, so the paper is a little wavy, but
perfectly legible. I also have the S-5879A angle plate kit which
sells for $23.75. I'll take $15 plus shipping for that if anyone is
interested.
http://www.statecollegecentral.com/metallathe/S-5879A.html
I'll sell both kits for $90 + shipping. Otherwise, I'll put them up
on Ebay. Contact me off-list if interested. c (8318) |
| 9" Cross Slide
Slop Diagnosis Help |
| I have a war
production 9" Model A with with .031 fore and aft slop in the cross
slide. Fore and aft = grabbing the cross slide and rocking it back
and forth. There is a gap at the cross slide dial of .023 If a .023
feeler gauge is put in this gap and the fore and aft slop is
remeasured it it .008. I seem to remember replacing the cross slide
nut several years ago. I have loaded pictures to this site below.
There are 4-5 pictures under "Machine Tools". Doc (9945) |
| From your
description it appears that the slop in in the hand crank/dial/screw
assembly rather than the feed nut. I have an assembly drawing an it
may be possible to remove this slot by tightening the slotted screw
holding the crank However this seems to be pinned to the knob. I
don't know how the pin is removed. Somebody who has done this may be
able to tell you how. removing this would allow you to turn the screw
1/2 turn at a time to lower the slop. Not a total removable however.
There do not appear to be shims for "fine: adjustment. My lathe has
considerable more slop but its definitely in the feed nut.(9950) |
| Doc; There are
several ways to deal with this. Please see the attached JPG before
deciding on the best fix, once you understand the fitting of a new
screw you can make a decision based on your particular machine.
Simplest: Can you press the graduated collar against the bushing for
the leadscrew and tighten it? Cheesy, but a way that works on some
lathes depending on the location of the wear. Almost as simple: If
option 1 doesn't work, turn a brass or bronze washer 0.023 thick to
go between the graduated collar and the leadscrew bushing. If option
1 does work, stick the washer between the handcrank and the
graduated collar. Still cheesy, but not as bad a kludge as option 1.
The official South Bend recommended correction: Attached as a JPG. I
thought this was in the files section of our group, but didn't see
it there. NOTE: figure out just where the wear is before following
this spec. You might only need to do steps 1 to 3, just step 4, or
the whole deal. Step 5 is for new screws that don't have a pin slot,
or cases where steps 1 through 4 took enough off enough metal to
have made the pin slot too shallow. You can do this on the lathe
being repaired, but it's a pain in the rear as you have to set the
compound exactly perpendicular to the spindle axis and use the
compound to face. You'll have to lock the cross slide at a workable
position via the gibs as the screw, bushing, and collar are mounted
in the chuck. Pad the chuck jaws with brass shimstock to avoid
dinging the leadscrew threads. The remaining 8 thou isn't something
I'd go through the flips and twists needed to get down to the 3 to 5
thou you set a new lathe up for. Stan (9955) |
| I'm still sort of
processing but am I correct in my reading that the .023 is the
problem, while the .008 is a tolerable amount of wear for an
originally acceptable .005 measure ? Also I'm not sure I was
completely clear: I replaced the cross feed nut but NOT the
leadscrew. I have yet to figure out how the cross feed leadscrew and
handle assembly disassembles. Doc (9959) |
| Yes, the .008" play
is due to the fit between the feedscrew and nut. BTW, you may find
that it's less than .008" at the far end of the screw. Disassembly
of CF screw: The slotted nut at the crank end of the screw is RH
thread. Make a notched driver. Remove the crank and dial. There are
a few small parts to avoid dropping on the floor: a small pin which
keys the crank to the shaft, and the pin and shoe to lock the dial.
Nothing spring-loaded though. The screw support bushing is also RH
thread. Most have a hole on the underside for a pin spanner. The
group has commented that some bushings do not have the hole. Most
people have been able to unscrew the bushing by clamping it using
wood or leather pads to protect the bushing from the vise jaws or
big vise-grips. (9972) |
| Doc; Short
answer - Yup! Some ways to get the handcrank off are at the bottom
of this post. Long answer: In almost all leadscrew setups, there is
some free play required between the nut and the screw to allow
smooth motion while not being so tight as to cause premature wear to
the nut or screw. This is the minimal backlash for a particular
combination. Ballscrews can have zero backlash, but they aren't
appropriate for manual tools as they rely on stepper or servo
holding torque to keep the table/cross slide/ whatever from
creeping. The leadscrew itself has to have some endplay unless you
have a setup using thrust bearings. This can be misinterpreted as
backlash. Plenty of folks have snugged up split feed nuts on
mill-drills trying to eliminate "backlash", when the real problem is
endplay of the screw. If I'm not sure of just how the error is
distributed, I mount a dial indicator to indicate the end of the
leadscrew shaft and lock the gibs. Turn in firmly, and zero the
collar and dial indicator. Turn out firmly. The graduated collar
reads the total apparent backlash, the dial indicator tells how much
of this is contributed by endplay. Total indicated backlash minus
endplay equals actual screw/nut backlash. In your case, the quickie
indication is that you have somewhere over 30 thou backlash. From
your post and the pics on your site, it appears you have some fairly
small amount (0.008") of backlash in the screw/nut, and a large
(0.023") end play in the leadscrew. You can get endplay down to 1
thou or so using the approach outlined by South Bend. Once the
endplay is fixed, you may find 8 thou backlash throughout the range
of motion for the cross slide. If this is the case, you can live
with it, replace the nut again (maybe you'll get a better fit, maybe
not), or try one of the assorted methods folks have devised to take
up a bit of the backlash. Most of these methods involve splitting
the nut and compressing it, or making one part of the nut adjustable
so you can rotate part of the nut to take up the backlash. A
constant backlash almost always means a worn nut, oversized female
threads, or an undersized leadscrew. Leadscrews just don't wear
evenly over the entire range as they aren't used equally over their
entire range. It's more likely that you will find a range from 8
thou to something smaller or larger over the range of motion. The
smallest number will probably be with the cross slide far out or in
past the center cutting point. This amount of backlash is pretty
much the lowest you can get with the existing nut, and is set by the
wear of the nut and fit of the nut to unworn screw, plus the small
(1 thou or so) endplay, something you have to have or the leadscrew
couldn't turn. Without modifying the nut or making a custom nut,
this is it, the least backlash you can have on your machine. In some
portion of the motion, you'll likely find a few thou more backlash.
This is a combination of screw wear PLUS the basic backlash of your
screw and nut combination. And of course the small but non zero
endplay of the leadscrew. About the only way to handle a worn screw
is to live with it, buy a new leadscrew from SB (very expensive, for
the SB13 the cross slide leadscrew was quoted at around $1375), or
buy precision acme left hand threaded rod from MSC. Turn down a stub
on one end of a length of threaded rod, cut off the worn screw, and
bore out the unthreaded portion of the existing leadscrew body to
let you silver solder/pin/press fit/loctite a new length of screw to
the existing leadscrew body. You'll have to hold the body of the
leadscrew in a 4 jaw and dial it in zero-zero or use a collet, you
really want the screw centered to within a tenth or so in the
leadscrew body. It's a touchy job to do well. Plenty of folks have
done it, it's just a first job of the day rather than just before
bed bit of work. Yes, you can cut your own leadscrew, but the effort
required and the likelihood of generating a screw with more error
than the 9 thou per foot even the cheapest acme threaded rod is
guaranteed to have worst case makes this something you only do out
of desperation rather than choice. I think a 3 foot section of the
correct threaded rod is only around $36 or so from MSC and you'll
have enough for 2 or 3 sections. From all of this, you can
appreciate why I wouldn't chase the 8 thou lash in the screw/nut, it
just isn't excessive and fixing it takes a fair bit of time or a
large bit of money. If you have a badly worn screw, such as the one
on my old beater SB13 that ranges from 6 thou up to 40 thou then
back down to around 8 thou of backlash , replacing the threaded
portion of the leadscrew may make sense. I would if this was my main
lathe, but on the rare occasion I need to dial in a really close
cut, a dial indicator can be rigged up easily enough or the compound
can be used for tool advance as it's leadscrew is in good shape.
I'll do it one of these days, it just isn't a priority as this lathe
is rarely used. To remove the nut that has the split screwdriver
slots that secures the handwheel, you can grind a notch in the
center of a large screwdriver and then grind the blade to fit. A
nicer approach that is easy if you have access to a mill is to drill
a hole (3/16 comes to mind, but it's been a while!) into one end of
a piece of 1/2 inch drill rod, face it nicely, then use the mill to
create a screwdriver blade with a nicely sized gap in the middle. I
made mine with a hex on the far end so a socket on a small ratchet
could be used to drive the tool. Others have pressed pins into a
piece of aluminum or steel stock 1/8 inch thick and 3/4 inch wide,
then ground flats to fit on the end of the pins. Just a pin spanner,
but made for slots rather than a pair of holes. Like most things,
there's any number of ways to get the little bugger off and back on
without doing anything tacky like using a punch and hammer - a BAD
idea, you'll bend the part of the leadscrew that sticks out past the
mounting bushing. Once the nut is off, you'll find the handcrank is
prevented from rotating by a small pin that is pressed into a hole
drilled half in the handcrank, half in the outboard end of the
leadscrew. Try not to loose this pin, seems it was some odd 64th
size bit of stuff on at least one of my lathes. I had the right size
in stock, but unless you stock a full range of smaller sized drill
rod it could be frustrating. I guess you could always open up the
hole slightly and use some size already on hand. Stan (9993) |
| When I first got my
SB lathe I trawled the net endlessly for information about it, and
SB lathes in general. I came across one well illustrated site that
showed an operation on a leadscrew (main leadscrew) done in much the
same way that Stan describes here. If I can re-locate it, I'll post
a link. Len
(9999) |
| Needing to remove
my crosslide hand cranks last evening (I'm about to fit the larger
direct reading dials) I duly made a notched driver and removed one
nut easily. The other, that already looked a bit "animalised" would
not shift at all, and curiously, looked deeper set within the boss
of the crank handle. On close inspection, I saw that the end of the
spindle had been centre punched quite hard, presumably as a means of
ensuring the nut didn't come off. I tried drilling that out, tiny
bits at a time, but still could not move the blasted nut, even with
the driver supported by my belly, and a stillson wrench on the
screwdriver blade, so I drilled the damn thing out until I could
remove the nut and crank. It looks as though the threaded end had
already been broken off, hence the machined inset into the crank
handle to allow pick up on what remained.. What with the break and
the small amount that I drilled out, I no longer had enough thread
to be comfortable with. I locked the top slide in position, removed
the leadscrew, chucked it and drilled a hole down into the end,
which I tapped M4. I now have a mushroom headed machine screw
holding the crank handle on, and although it is a Phillips cross
head, looks virtually identical at a quick glance, to the original
nut. Len
(10057) |
| New
Cross-Slide Threaded Rod |
| The threaded rod
(and the bronze "nut") on my "new" 13" South Bend are worn to the
point that the acme threads look like wide spaced UNC threads. What
are the prospects for replacing this rod? Since the lathe has a
taper attachment, there is an extension beyond the threads and "end
flange". I don't know if this is all one piece or separates at the
flange. If one were to undertake making a replacement, would drill
rod be the right material? Would that be water hardening or oil
hardening, and what would the hardening process be? What are the
alternatives i.e., live with it, buy a new one, buy a used
one. Mark
(10355) |
| Mark- If all else
fails, see me for a new one. Rose Marvin (10357) |
| Search the
archives. I think this was discussed and written up in the files
section. IIRC splicing in a piece of a |
