| More Compound Help (Jun
2, 2001) |
SB Heavy 10 Compound Bolt
(Sep 28, 2003) |
| Purpose of Screws on Compound?
(Nov 27, 2001) |
Compound mounting base?
(Nov 11, 2003) |
| Compound problems (Jan 2,
2002) |
Compound Brass Nut (Mar
18, 2004) |
| Wear on compound rest
(Jan 18, 2002) |
Bent Compound rest screw
(Mar 25, 2004) |
| Compound setting (Jan 30,
2002) |
Newbie question on compound
(Apr 13, 2004) |
| Heavy10 compound thread
(Feb 9, 2002) |
Question on Saddle/Compound
(Aug 8, 2004) |
| CR Top/Swivel (Aug 22,
2002) |
Compound (Sep 28, 2004) |
| Thread specs on compound screw
(Nov 20, 2002) |
Brass insert on the compound
(Jan 22, 2005) |
| Model 9 compound rest (top)
(Dec 1, 2002) |
T nuts for 9" compound
(Jan 23, 2005) |
| 10" Compound Slide Gibs?
(Apr 12, 2003) |
Acme Taps for Brass insert on
the compound (Jan 25, 2005) |
| Compound stuck (Jun 13,
2003) |
Newbie question: cross and
compound play (Jan 28, 2005) |
| Cutting the corner off the
compound (Jul 30, 2003) |
Compound Screw Fix (Feb
14, 2005) |
| Compound problem (Sep 2,
2003) |
|
| |
| More Compound Help |
| I can't figure out how to disassemble
the compound rest itself? It definitely needs disassembly and
cleaning. If you wind the compound all the way forward, it doesn't
slide off the dovetail like the the bigger dovetail one on the
saddle works. George (768) |
| If I remember
correctly, there is a screw in the bottom of the compound that holds
the nut for the compound feed screw. Remove this screw and then
remove the gib from the compound. Now you should have enough
clearance to slide the top half of the compound off of its base. If
the nut is stubborn, rethread the screw part way back into the nut
(the bottom screw I mean) and give it a tap on the head to push the
nut out of its recess. Do this AFTER the gib is out. When removing
the gib, don't forget to loosen the set screw on the side of the
compound BEFORE you try backing out the gib adjusting screw. As to
making a tapered base (or plinth) for your toolpost, set your
compound (after you get it all back together) to the angle required
and use it to machine the short taper back towards the chuck. Webb (770) |
| I'll
keep tapping on the leadscrew nut to see if I can loosen it. Can't
seem to get the gib out though. It will slide towards the rear
easily but then bumps into the dial housing. I'll keep messing with
it. George
(774) |
| I think that
you may have the "Large Dial" version. In that case, take the
compound assembly over to the bench vise. Pad the jaws of the vise
with lead (my choice), leather, hard wood, etc. to protect the
finish on the dial and collar. Tightly clamp the dial and collar in
the padded vise. Have the compound oriented so the body and screw is
straight-up. Watch out for the thumb screw. You don't want to crush
it. Now grab the body of the compound and unscrew it from the
collar. The collar will remain in the vise along with the whole ball
crank, dial and lead screw together. Watch out! If the nut on the
lead screw is already near the end, in may bottom out before you can
get it apart. If you run into this, just remove the compound from
the vise and crank clock-wise on the ball crank while holding the
collar still. Then you should be able to finish unscrewing the ball
crank lead screw assembly from the compound casting. I leave the
rest to you. Webb (779) |
| Purpose of Screws on Compound?
|
| My parts list is
packed away and I have a question on the compound slide for a Heavy
10. There are two screws on the top of the compound slide. Are these
oil holes only or should they have a shoe in them which bears
against the compound screw when you tighten the set screw?
George (2268) |
| Both are strictly for oiling
access. And simply fill the holes to prevent debris from entering.
Joe (2269) |
| Compound problems |
| Having a problem
with the compound on my 9-inch. When I set it to 90 degrees [as
indicated from the front, it's about 2 degrees off [as indicated
from the back]. or vice-versa. it's as if the two pointer lines
scribed in the top of the cross-slide aren't exactly 180 degrees
apart. I can figure out easy enough which one is right [it would be
whichever one cuts a taper-free workpiece just by using the compound
leadscrew], but how to correct the other one? I'm hesitant to remove
ANY material off the top of the cross slide until I know what I'm
doing. Is it supposed to be that way for some reason I'm not aware
of? I have 2 compounds and they're both off the same amount so I
know it's the lines in the cross slide and not the protractor scale
on the compound. Lurch (2547) |
| Any markings
engraved on the lathe anywhere are for reference only. For accurate
settings always use a gauge of the tolerance of the job you are
doing. If the job says +/- .005 or less use a micrometer, if the
tolerance is greater use a caliper. For setting angles always use a
machinists protractor. For rough angles as for chamfers and thread
cutting the $10 stainless ones will do. For more precise angles you
will need a $30 or better unit. JWE
(2549) |
| At the back, it's
off the same way either spin. As it turns out, according to Ralph
and Randy at the factory the index lines on the front [one straight
and two at 45 degrees] are OEM, the one on the back was put there by
a previous owner for whatever reason...setting to indicated 30 at
the homemade line puts the compound at actual 29. Maybe someone who
owned the lathe before did a lot of threading. Lurch (2550) |
| Wear on
compound rest |
| Brian: I think that
you'll also find that the dovetail way under the compound rest
casting has probably worn more at the ends, and there will be an
elongated round bump in the middle. This was the case with my
compound rest. When that surface is rounded, it allows the compound
rest to twist while sitting on top of the saddle. Obviously, this is
a serious problem, since the lathe tool will rock as you move the
cross slide in and out. Try twisting the compound rest and see if
you feel any play. A quick fix for improving this situation is to
remove the bump, by grinding, sanding, filing, and/or scraping. Then
the compound rest can bear near the ends. An even quicker fix might
be to try cementing in a pair of brass shims, one at each end of the
compound rest. (2803) |
| Make sure I
understand you right--are you referring to the compound dovetails,
that if I disassemble the compound, a straight edge placed atop the
bottom half of the compound, will rock? Or do you mean the top of
the carriage that the compound assembly sits on is convex? I know
that if I am doing a facing cut and go too far, past center, the
whole compound shifts. (2808) |
| Brian, See the
attached sketch for the surface that I am talking about. It is the
dovetailed section within the trough of the compound rest casting. I
think that if you put an abrasive, such as lapping compound, in the
ways, then that will wear that surface even more rounded. Jon (2811) |
| I think
the wear you describe, is the same thing I referred to as 'wasp-waisting'--the
surface you describe as wearing in the sketch, which wears convex,
slides on the surface I describe as wearing concave. I suppose the
only right way to do it is with a mill and a dovetail cutter. But I
will take some measurements and see whether the experts think it's
even worth addressing. (2813) |
| Compound
setting |
| I know that this
was said a while back, but I'm scared to do a search of "crosslide"
in Yahoo . My question is, what degree would you set the crosslide
at to get a .0005 cut (or smaller) when turning it .001 on the dial.
Matt Pierce
(2998) |
| Thirty or sixty
degrees, depending on how you want to measure it. You are looking
for an angle whose sine (or cosine) is 1/2 Chris (2999) |
| 60 degrees Paul R. (3000) |
| To determine the
amount to dial "Y" on the compound to remove "X" with the compound
set to angle "n", divide the amount to be removed by the sine of the
the angle. Y = X/sin(N) This is plain trig, with the amount to dial
being the hypotenuse, and the amount to remove being the opposite
side. Kind of hard to see when you are looking at a 3D object like a
lathe. If you are set 30 degrees with respect to the lathe
centerline (some lathes such as the 9x20 are bassackwards, and are
marked with respect to Y axis leadscrew), 1 thou indicated on the
dial will give half a thou of infeed, of it you like, 1 thou of
diameter reduction. If you want to find the angle that will give
some ratio, such as 1 thou dialed in giving 1 tenth of cutter infeed,
divide the amount of desired infeed by the desired dial increment,
then take the arcsine of the value you get. As an example, we want to
remove 1 tenth per thou indicated on the dial. 0.0001/0.001 = 0.1,
arcsine of .1 is 5.739170 degrees. Have fun dialing your compound to
this setting! At least you know how to get the values. Your question
was 0.0005 cut for 1 thou infeed. 0.0005/0.001 = 0.5, arcsine of .5
is 30 degrees. You can do the same trick for precisely dialing in a
cut if facing a part to length, just use the cosine rather than
sine, as you are feeding towards the headstock rather than towards
the center line. I guess some import lathes get it right for the
sine function as long as you are facing. Darn irksome having three
lathes with 2 different ideas about 0 degrees though. One warning -
if you are using a carriage stop or dial indicator on the carriage,
the tool tip will move faster towards the headstock than the depth
of the cut increase would make you believe, at least if you are
using an angle less than 45 degrees. The shallower the angle, the
more the tool moves towards the headstock, until at 0 degrees 10
thou dialed in moves the tool 10 thou towards the headstock and zero
towards the centerline. Obvious once you think about it, as the tool
movement towards the headstock is the adjacent side, but easy to
miss this effect the first time. Stan (3001) |
| Just don't make the
mistake I did of setting it to 60, then wondering why the offset is
something like .87 to 1 instead of .5 to 1 because you're working
off the wrong side for the triangle. I had mine set to
30-off-straight-or-60-off-parallel-to-bed like for screw cutting, and
was trying to use the 1:2 ratio for depth-to-a-shoulder. should seem
simple, but this is what I get for making chips when I should be
making z's. (3004) |
| That's why I said
60 degrees. That's the angle you set on the compound. Paul
R. (3005) |
| Heavy10
compound thread |
| Dennis, Thanks for
the report on your work. The Heavy10 compound screw is 3/8" - 10tpi,
RIGHT HAND. It is right hand because the screw moves with the top.
(The cross feed is left hand because the screw is mounted on the
saddle, and doesn't move with the cross slide.) The way to remove
the compound screw and nut, I think, is to take off the compound
assembly from the cross slide, and unscrew the fillister head screw
that holds the nut from underneath. You may have to remove the screw
first, I forget. It should become clearer once you remove the
assembly. Jon
(3159) |
| Dennis, I just
took apart the compound from my 9" C. It is 3/8" RH Acme the same as
Jon writes below. You do have to remove the screw and bushing from
the base to remove the nut as well as a set screw that keeps it
tight in the base. Once the nut is loose, you stick your finger in
between the slide and the base and push the nut back towards you.
The slide won't come off the base until the nut is out. This will
make more sense to you when you have it all in front of you. The nut
itself is very simple. 5/8" bronze or brass 1 1/8" long drilled
crossways 1/4" from one end and tapped. I made my own cross slide
nuts using 3/4" sprue from the local community college bronze
casting class recycle bin. I turned the rod true, drilled and tapped
it on my lathe and then silver soldered the rod to another piece
drilled and tapped for the set screw and pin. I made a tool to cut
the LH Acme from a piece of drill rod ground to the Acme thread
shape and a small boring bar to hold it. Glen (3166) |
| CR Top/Swivel |
| I am still trying
to separate the CR Top from the Swivel, the lead screw through the
CR Top does not slide the top, it just turns and nothing happens.
How do I separate these two pieces, the book shows a bushing, collar
and then the handle, I have the handle and collar removed, how is
the best way to remove the bushing so I can slip the top off the
swivel. Or I am I looking at this the wrong way? Clint (5929) |
| Go back to
my last post on this with the pictures. Once you have the feedscrew
out you have to drive the bushing out the bottom of the assembly
before you can separate the two pieces. Dave (5932) |
| This is what is
confusing to me, I had no problem separating the compound from the
saddle, but the tool post holder from the swivel, there is no way to
remove the lead screw, and you can only get to the outside end of
the brass nut inside of the swivel. The leadscrew in the tool post
holder just turns freely and does not back out? Matter of fact it
does not even move the tool post. Clint (5933) |
| Dave Are you
talking about going from the inside of the tool post holder and
driving out the bushing that is behind the collar? What do you
recommend to use to drive this out? I would have to go in at an
angle and it sure would take something pretty small like a 6 or 8
penny nail in order to manipulate to get to the bushing. If I could
get the tool post holder to screw on out it would not be as bad, but
like I said, I guess the screw nut is stripped out and I cannot get
it to carry on out to it's fullest. Clint(5934) |
| Clint, The collar
that holds the feedscrew in place has a small hole in it intended to
let you grab it with a special wrench and unscrew it. I used a small
( 1/4" long ) piece of drillrod in the hole and vice grips ( before
everyone cringes I used brass shim stock to protect the bushing )
With the collar unscrewed the feedscrew will come out. With the
feedscrew gib strip removed you're down to 3 parts the top, bottom
bushing. I initially drove the bushing up from the bottom and into
the compound once it moved partially I was able to hose everything
down with penetrating oil and then drive the bushing back down and
theu the bottom. I used a small pry bar to do this but a wide
flat blade screwdriver would also work. Get back to me if you're
still stumped. I'll take mine apart again and post the pics to
illustrate the procedure. The real trick is loosening up the brass
bushing so that it will move and then come out. Dave (5936) |
| That is the problem
I am having, the screw will not come out. I have the collar removed.
I still maybe missing something here, all I have left is the screw,
bushing and screw nut inside. Clint (5941) |
| Clint, Does the
feedscrew turn and if so does it advance back out as it's turned in
each direction ? Dave (5942) |
| The screw turns but
it is not advancing either way, neither is the tool post moving.
Clint (5943) |
| Thread specs on
compound screw |
| Does anyone know
the specs for the thread on the end of the compound screw? The nut
on the one I purchased is missing and the threads are damaged. John
(6942) |
| I managed to
repair the threads with a small 3 cornered file. I ended up using a
#12 nut with some form-a-thread for the retaining nut. If I ever
develop the ability to do an internal thread or make a tap I will
make a new nut. As I mentioned in the previous post the thread
appears to be somewhere between a #12 and a #10. IIRC it is 24 tpi.
John (7466) |
| Model 9
compound rest (top) |
| I'm
looking for the top of a compound rest for a south bend model 9"
lathe. If any one has has one for either sale or trade let me know.
Bill
(7672) |
| I have a spare you
can have for $35. It's in decent shape and the leadscrew isn't all
trashed.(7711) |
| Lurchix, I'm definitely interested.
Can you tell me what the diameter of the post is that goes into the
compound base. The post on my lathe is 1 3/8" dia. If it is the
correct dia. I'll send you a money order. Bill (7730) |
| The part I'm looking
for is also called the cross saddle. In one of the South Bend parts
list they refer to the part as the compound rest top, hence my want
message. this is the part that holds the tool post. On the bottom of
the part is a part called the swivel and this part has a 1 3/8" dia
post that fits into a hole on the compound saddle. If this is the
part you have then I would like to buy it.
Bill (7731) |
| 10" Compound
Slide Gibs? |
| Are the gibs
(should saw "gib" singular) on the compound on a 10K on some type of
taper ? My compound is sticky and tight. In attempting to clean the
gib I found that it is held in by the socket head and that the small
slotted screw on the side is some type of lock for the socket head.
When I completely tighten down the socket head, the compound binds.
When I try to remove the gib it only seems to remove on the dial end
but does not clear the dial. Am I missing something ? (10169) |
| Yes, it's a tapered
gib. And you've already figured out the adjustment and lock screws.
I believe that you have to loosen the gib and back out the feedscrew
to remove the top half of the compound. (10188) |
| Compound stuck
|
| I can't get my
compound off the cross slide. The tapered pins must be stuck or
crooked or something. Any tricks on getting them out? I was thinking
about a magnetic parts pickup but I can't find one small enough. A
3/16 brass dowel and Crazy glue? Jim
(11980) |
| From your
post I'm assuming this is the sort of compound with the square head
bolts in the cross slide that secure the compound rather than the
set up on the old 13's: Remove the clamping bolts that point towards
the center for the compound swivel from the cross slide completely.
Squirt some WD40, Kroil, kerosene, varnish/gunk softener of choice
in the bolt holes so it can soak around the pushers (plungers).
Wiggle the compound a bit. If it won't come out yet but loosens up a
bit, squirt more of the kerosene/kroil/whatever down onto the recess
under the compound. With worrying the compound and a bit of solvent
available it will come out, just might take an overnight soak.
Stan (11981) |
| If the procedure
below fails, one thing I can add to this that has worked for me in
this same endeavor. Remove the saddle from the lathe. The apron can
be left on the lathe, just remove the saddle to apron mounting
bolts, lock, and rear clamp bar. using a good sized piece of round (
mine was brass, but doesn't have to be) to protect the bottom of the
compound, tap the bottom of the compound with a steel hammer. The
sharp impacts will loosen the tapered pins. Don't beat hard enough
to do damage, the flat scrap round you are hitting the compound
bottom through will give adequate protection to the compound. Keep
tapping, squirting penetrant, and wiggling. The pins will finally
come loose. Clean and lube well before putting back together. Rich (11984) |
| I finally got the compound off. The little tapered dowels
were gunked up. A combination of WD-40 and some hesitant whacking
got the thing loose. I hate banging on things but sometimes it's the
only way that works. Jim (11993) |
| Cutting the
corner off the compound |
When a friend found
out I had a Southbend lathe, he offered to machine the corner off
the compound so that the compound could work closer to the
headstock. I told him no thanks. He asked "why not" and stated that
cutting the corner off the compound would let me work in tight
places. I told him that my lathe had been a school lathe and that
the students
had already machined the corner off the compound using the chuck as
the cutter. LOL Gary P. (13049) |
| I would strongly
suggest you keep this "friend" as far away from your machine tools
as possible. Scott Logan (13050) |
| Scott: I am
wondering about you reply! I would not machine the corner off a
perfect compound however, cutting off the corner of a compound that
is already beat up does let you get into some tight places that you
otherwise could not. As long as you stay away from the t slot
cutting off the corner of the compound does not affect anything.
Gary P. (13053) |
| On
the contrary, I believe it does. Removing any metal from a machine
tool, without careful consideration of the consequences, will
certainly be detrimental to the operation and/or accuracy. In this
case, removing material from the compound rest top will weaken it,
and eventually contribute to a possible failure of the casting. In
addition, I have been a machinist for over 25 years (I know, nothing
compared to some of you) and I have never come across an operation
on any of the lathes I have run that would require me to cut off
part of the compound rest top. Admittedly, I have precious little
experience with South Bend Lathes, but plenty of experience with the
VERY similar Logan Lathes, and several other brands as well. Having
said all that, this is just one man's opinion, and worth exactly
what you paid for it. Scott Logan (13054) |
| I have to agree
with Scott on this as with a proper tool post there is no way the
edge of the compound can be exposed to damage without first
destroying the tool holder and tool post. I am well known for making
what I see as needful modifications to any part of the lathe where I
see a design or manufacturing deficiency or lack. In the case of the
compound corners front or rear the is no physical reason for
notching or rounding them off. There are on most machines other than
South Bends many compound modifications that need to be made but
this is not one of them. JWE (13061) |
| Compound
problem |
| My heavy 10 has the
large style micrometer collar on the compound. I have noticed that
when I feed the compound forward the collar is acting as a bushing
to transfer the thrust of the screw to the compound itself. This
doesn't seem right to me, and causes the collar to slip and loose
its setting. If I remove the collar and then crank the screw it will
move into the compound about 3/8" before it begins to push the
compound forward. Any ideas what my problem might be? Zach
(13733) |
| In all
likelihood either your compound nut or screw (or both) is worn out.
A disassembly and inspection is required to verify which is the
culprit. Ron (13734) |
| I have a 9"
which I think should be similar. It's been a while since I had the
compound apart but IIRC what you describe is exactly what happens.
To get the dial to hold you need to tighten the set screw in it. At
least that is the way I remember it. John (13735) |
| That's interesting.
I just assumed that I had something missing or assembled
incorrectly, but I guess it is possible that the micrometer collet
is supposed to transfer the thrust of the screw to the slide. I can
tighten up the set screw and the collar will hold, it just doesn't
give a nice smooth feel when cranking the compound forward. If it
really is supposed to work like that I might modify the collar the
include a small thrust bearing which will hopefully result in
smoother operation. Zach (13736) |
| When I fitted the
larger collars as replacements for the smaller originals on my 1942
#C, I needed to make a corresponding 'spacer' to fit between the
smaller bush and the collar, to carry the index mark for the
graduations to line up to. I turned the face that fits against the
collar with a slight concavity, so that only the outer edge bears
against the collar, thus reducing friction between them. Len
(13737) |
| SB Heavy 10
Compound Bolt |
| I just snapped the
head off the gib adjuster bolt on the compound slide on my SB Heavy
10 (the one with the tapered gibs). I'm presuming I can get the bolt
out but does anyone have any leads on a new bolt ? (14198) |
| Forget to loosen
the locking screw on the side? The compound and cross slide use the
same size gib adjusting screw and both have locking screws with a
small brass insert under it, tangent to the thread. In a pinch you
can use a long set screw and short piece of round stock (disc)
tapped and brazed to hold it in place until you can get or make
another adjusting screw. JP (14199) |
| We make things like
that from stripper bolts; shoulder bolts. They will have the
appropriate Allen head. Just turn and thread with carbide to suit.
Joe (14200) |
| Compound
mounting base? |
| If anyone out there has a picture of a compound mounting
base, I'd love to see it I am in the process of trying to make one
fit where it is not supposed to fit (a heavy 10 on a 16" SBL) I have
a crosslide, but not a mounting plate, and I don't have a clue how
it is supposed to look? Also I have problems
sometimes getting pictures off this site? Trucks (14930) |
| Hey, dude I have a
complete compound off a heavy 10, I am looking for the part that it
bolts to with a hole in it and it mounts to the crosslide. Trucks (14977) |
| The cross slide is
the part with the hole in it that the compound mounts to. Your 16"
lathe has a larger hole for the 16" cross slide. The hole you need
is 1.625", you will have to make up an adapter plate to mount that
compound or get a Heavy 10 cross slide and chop it up. JP (14978) |
| I didn't know it
was made into the crosslide, but my 16" does not have a hole in it
for a compound? it has 2 sets of T slots 2 that run with the
crosslide, and 2 that run horizontal of the crosslide, I will have
to make a adaptor that will bolt to my crosslide, and someone else
said that I would have to space up the compound? Right now with the
compound just sitting on the crosslide the top of the compound is
almost centered with the center of the chuck, and by the adjustment
of the toolpost I figure that I can do anything I want to do with
it? Any comments? (14996) |
| Terry, It sounds
like you may have a "production" type cross slide. Often lathes so
equipped also had a bed turret installed. Did yours come with a bed
turret? Anyway, you may want to get the "regular" cross slide that
uses a regular compound. Production cross slides used tooling blocks
that held tools more rigidly that the lantern style toolpost did As
to the manual I have, it really isn't any different that the one SBL
offers. Just older and I've collected a few extra pages over the
decades. Parts of it are photo copies and some of it is the older
loose leaf variation printed in brown ink. These don't copy very
well unless I play with the contrast to help bring out the details.
I had to do this with the cross feed screw fitting instructions I
posted recently. As I come to think of it, didn't someone post a
copy of the 9-10K lathe parts book a while back? Webb
(14997) |
| Yes I do have a
production lathe, and it did have a turret tailstock, but it is MIA
and I don't have anything now, but I will probably just make an
adaptor for this compound as I have several good machinist friends
that just love me cause I am always coming up with this kinda stuff
to do. Always a challenge. Trucks (14998) |
| Compound Brass
Nut |
| Want to buy A
compound rest brass nut with the oil hole on top. Would like to get
a new one , will take a rebuilt one. Maybe some knows where a brass
nut is that has be reworked. Mine brass nut has bet the dust, maybe
there is someone that could rebuild mine? This is for my 13" SBL.
(17814) |
| What size acme
thread does your compound have in it? My 21" has a 7/8s left hand. I
got a 7/8" left hand nut from my bolt suppler and went from there,
worked great. The nut was steel but still worked. Duane (17832) |
| Bent Compound
rest screw |
| My compound
rest screw has a resistance half way through its 360 degree travel..
investigation showed that its bent.. not badly, but enough to cause
tension against the pivot (compound rest nut?) causing a 3:1 tension
difference when turning the compound slide. Now, without laying out
big bucks ( these things are pretty dammed rare In Oz, unless
someone can correct me to a good supplier) that my current
thought/option might be to heat/bend it back to a reasonable shape.
Tough ask I know. But I'm sure someone has tried and succeeded in
this before. Garry D
(17970) |
| Most things metal can be straightened if you take enough care when
doing so. It's like the metal has a "memory" of the original shape.
You may not get it perfectly straight, but you can get close. Use an
arbor press and "V" blocks pressing on the high spots. Use aluminum
between the arbor and the screw to avoid dinging the threads. If you
can get it close enough to working order, you can then make a new
one on your lathe and replace the bent one. Don't use heat as that
could lead to stretching and/or overcorrection.
(17971) |
| A good way for a
"controlled" straightening, is to chuck the bent screw and then use
the cross slide to force it straight. Use a split pipe collet around
the screw so you don't ding the threads. Chuck it so the bend is up
against the chuck. Dial the outside end to determine how far out you
are, push on it with the cross slide and redial. Repeat as
necessary. You can get within thousandths this way if you're patient
enough. John (17977) |
| Newbie
question on compound |
| I recently bought
an sb9 and know nothing about machining yet. I suspect the dial on
the compound is somehow broken or needs some tlc. The graduation
ring (for lack of exact term) turns no matter what I do. I thought
it should be settable to zero just as the tool touches so you could
know how much the advance was, but mine don't seem to be able to be
stopped from 'freewheeling' even though the hand crank is still.
How/what needs to be done?
(18395) |
| There should be a
small thumb screw which presses against the shaft when tightened up,
loose the dial should freewheel and tight it should lock down by
friction. JP (18396) |
| It may be a slotted
set screw. Jim B. (18402) |
| Cannot seem to turn
it! What next, force it? Would hate to break it off. (18413) |
| Question on
Saddle/Compound |
| I took
apart the Saddle / Compound on my 9" South Bend and a part fell out
and I can't quite figure where it belongs. It is the Lock Screw and
Lock part numbers 28 29 on page 8 of the Army Manual. My question
is: Where exactly does this go, the picture does not really indicate
this. Ray
(20423) |
| That is the
carriage lock screw. It goes back in after the saddle is put back
on. There is a 1/4" hole on the bottom right side for the pin then
screw in the bolt. Bob (20433) |
| They go in the
front right corner of your saddle. Used to clamp the saddle to the
ways when your facing a part. Look for an extra hole just in front
of the right hand screw that holds the apron to the saddle.
Walt (20440) |
| Compound |
| Is the compound for
the 9" C supposed to have limited movement? Say 3 or 4 turns of the
knob? It looks as if the two screws, the one in the neck of the
compound and the one that actually moves the assembly. Are made out
of one solid piece? Gene(21113) |
| I have looked
through the files and pictures and searched for "compound feed
diagram" in the messages with no luck. I am cleaning up the carriage
and the compound feed from the feedscrew to the handle is rusted
into one piece and I can't tell where things are supposed to come
apart. Does anyone have a diagram showing how this comes apart/
together? Gene
(21114) |
| Have you
gotten a copy of the army manual or a SB parts manual? you really
need to look at the parts breakdown. again, link to the army manual
download in the FAQ. you really should have a peek at it. Things may
make more sense once you see it. The compound does not sound right.
it may be that its all gummed up or rusted up. Collar is spanner
type nut that iirc is LH threaded. The spanner hole is there, it may
be gunked up. dennis
(21115) |
| Gene and Dennis,
The collar is RH threaded. Gene will need to make a two prong tool
to remove the nut that holds the handle on the bushing. There is a
picture in the photo section of a beautiful tool for this. A big
screwdriver with a notch cut out will work. The bushing will unscrew
from the casting, though there may be a set screw to hold it. I
padded my vise jaws wit leather to grasp the bushing and twisted on
the casting to get mine out. When you have the bushing loose,
unscrew the leadscrew all the way from the feed nut. A set screw
holds the nut in the casting. The nut is pushed out from the inside
so you can slide the dovetails apart. Dennis is right, download the
manual. A picture is worth more words than I want to write. Glen
(21117) |
| Glen, Which file in
the photo section is this pic in? I can't find it.
Steve (21118) |
| The Army Lathe
Manual with the pictures he spoke about is here:
http://metalworking.com/dropbox/_2001_retired_files/sbarmylathe.pdf
Download the manual and save it for future use, it is a great
resource. Terrance (21124) |
| The spanner holes
are there but everything else appears rusted together.
There's no gap visible on the collar. But the design on that link is
obvious. Oil and elbow grease should do the job. But without the
design it wasn't clear where the force should be applied. Gene (21127) |
| I'm new to this
group and have not seen that file before that has some really good
info. I wonder if there is a similar
file somewhere for the large SB lathes. I have a 15" and am not
having much luck finding anything about it. I'd like to know if the
parts a interchangeable with the 13, 14.5, and the 16". I need to
find half nuts and half nuts lever system.
(21128) |
| It's in the album
called FeedScrew. Glen (21132) |
| Brass insert
on the compound |
| The brass (looks
like turned barstock that has been drilled then tapped) insert in
the compound is worn and I was wondering what size tap is used on it
( I have a 9x14 sb ) also at the same time I could replace the brass
insert in the cross slide. if any one knows what size tap or where I
can get the brass inserts (maybe from Southbend?) it would be
great.
(24171) |
| You can get a new
one from http://millermachineandfabrication.com/ or from Rose at
Parts Works. Bob (24172) |
| I think you are
talking about the feed nut? That is the only brass insert I remember
in the compound or the cross feed. They are 7/16 - 10 LH Acme
thread. There are taps available at about $70 each. However if they
are worn then the drive screw is also worn. The have been many posts
about these. Rose at Parts Works (see links) can help, but read the
archives first. Jim B.(24173) |
| Where do you get
these taps? And where can you get the left handed acme in this size
or do you have to single point turn it yourself? (24174) |
| I found the taps
for about $23. I am going to order 2. Is the cross feed the same size
as the compound? acme cross about $70
(24176) |
| I believe I have
the source saved on my work computer. I will post it Monday. Jim
B. (24177) |
| That's an
incredible price for an oddball Acme tap. Do you remember where you
got them? (24179) |
| If memory
serves me correctly, isn't the compound of the 9 inch 3/8" x 10 RH
Acme? Webb (24180) |
| I just took mine
apart and you are correct 3/8-10 RH its the cross feed that's 7/16
-10 LH Sorry about that. Jim B. (24181) |
| T nuts for 9"
compound |
| Does anybody know
of a source for t nuts for the compound of the 9" model a? I have
not seen any locally. Mark
(24192) |
| MSC has T nuts in
almost any size. MSC Industrial Supply Co.
http://www1.mscdirect.com (24193) |
| I measure a slot
width of 7/8 a base width of 1 3/8 and a base thickness of 0.312
Enco does list a 7/8 wide unit but the base width is 1 1/2 and its
thickness is 7/16. wont fit. The next one is 11/16 with a base width
of 1 1/8 and a base thickness of 5/16 . This would go in but it
would need to be carefully centered or the base could grab on only
one side. You could superglue a some thin strips to keep it
centered. 1/2 -13 tapped hole. Part # DC407-2680 $2.12 (on sale) Jim
B. (24194) |
| I bought some
from Grainger Supply over the counter, but they are wholesale sales
only. You'll need to use someones business "name", then pay cash.
Also, McMaster-Carr has a big variety at:
http://www.mcmaster.com/
Search on "T nuts" Wade (24195) |
| Or you can turn
them from round bar like I did. And cut the bottom to the widest of
the t slot. I left mine a little taller, my tool block is
counterbored. Bob (24196) |
| I like Bob'
solution. Jim B. (24197) |
| I like Bob's
solution also. I just could not find any that fit at any of the
mentioned sources. Mark
(24198) |
| You can get
the one from Enco and then face off the back to depth and face off
the sides to the width you need. One thing about the threads, make
sure you make a bottom jamb so the center post does not thread thru.
if it does, it will most certainly rip off the cast iron ears of the
compound. Dave
(24200) |
| Acme Taps for
Brass insert on the compound |
| Someone was going
to post where to get modest price Acme Taps 7/16x10 LH for the cross
feed and 3/8x10 RH for the compound Monday. Did I miss this
information? Dave (24256) |
| Somebody stated they
had a tap for $30 so I did not post The only link I can find may not
be the one I was thinking of. Its a new catalog without prices. I
remember prices in the old one. That being so and noting DO NOT TRY
THIS ON A DIAL-UP. Its a BIG file.
http://www.e-taps.com
Click on the new
catalog link not the metric tap link If you have dial-up.
1-321-720-9242 The 3/8-10 RH is GARGP0375X10E The 7/16-10 LH is
GLARGP0438X10F Jim B. (24261) |
| That was the
correct link. Their prices are: 7/16-10 LH $73.00 3/8-10 $51.00
George 24266) |
| 7/16-10 LH $73.003/8-10 $51.00 At those prices, you might be better off
buying new nuts from Miller Machine and Fabrication. Prices listed
are: Cross feed nut $50.00 Compound nut $28.50
http://www.millermachineandfabrication.com/
No connection. Webb (24271) |
| Newbie
question: cross and compound play |
| The cross and
compound handles rotate quite a bit before movement occurs. What is
the best way to address this? We have a 9 inch and 13 inch SBL.
Mark
(24372) |
| Some slack is
normal. If it weren't there the screw would bind. Generally, rotate
the handle back past the point at which you are to begin measuring
for the cut. In other words if you want to set a cut by turning the
handle clockwise, first rotate it counterclockwise far enough to
take up the slop. Then rotate clockwise until the slop is taken up
in that direction. Set your bit to what you consider the beginning
point and then set the micrometer dial to zero. Measure from there.
By doing this you take up the slack. Now, is that as clear as mud?
The other option is to call or e-mail Plaza Machinery and get a new
screw and nut. Keep in mind though that even with a new screw and
nut there will be some slack. Greg (24374) |
| I have the same
question; I recently acquired a 9" Model A with quite a bit of
"slop" in the cross and compound slides. Is there any adjustment, or
is the culprit a worn nut? Jimmy (24392) |
| I just put a new
nut on my cross side and it is like new. Today I order a compound
nut from Joe at Plaza. Will wait and see if he has it. Dave (24394) |
| Who is Joe at Plaza? Jimmy (24396) |
|
www.plazamachinery.com Bob (24397) |
| I repaired my cross
slide on 10K with a new nut about 4 years ago and with $45 for the
nut. I got around to the compound when my parting tool dug into the
cold rolled and bent the 1/8 wide parting blade. This due to slop in
the compound nut was my summary. Now don't barf over this but here
is what I did. (what have I to lose?) I took the compound off-left
the nut in place and the threaded rod in the nut. Put the brass nut
placed vertically in my hydraulic press and gave the nut a squeeze
to make it shorter and the threaded hole smaller. It worked it is
80% better (about .008 slop on dial) but I won't bet any money on
how long it lasts. It sure feels nice now! Darrell (24399) |
| There are two
sources of play on both the compound and the cross feed one is the
nut, of course the other is the play in the screw, WRT the manner in
which the screw is held in the cross feed or the the compound.
Depending on how this play is found, machining a shoulder or inserting
a shim will minimize it. It cannot be made zero but it can be
reduced to 0.001" or a bit less. You need to measure whether its in
the nut or the screw mounting or both. I see no problem with
"squeezing" the nut except its a temporary repair. This will
result
in excessive ware on a small portion of the nut over time but will
reduce backlash in the short term. Remember that if the nut is worn ,
the screw is also worn, It will not be worn evenly over its length.
Squeezing the nut to reduce backlash in the middle will result in
excessive nut wear at the ends of the travel. Both nut wear and
screw wear should be addressed as a long term solution. Further
there is the issue of how much play is excessive. a few thousands or
even a few tenths of thousands can be managed, as has been
mentioned, by always insuring that the lash is removed by always
backing out and coming back in the same direction. I was taught this
at a very early age and just today I am a 71 year old PITA,
non-the-less removing backlash is SOP. If you, on the other hand,
decide to mill on your lathe and you need to climb mill the backlash
will hurt. Still look at both sources before you replace the nut and
remember to remove the lash and you may not need to change nuts and
screws. Jim B. (24401) |
| Compound Screw
Fix |
| There have been a
lot of threads in the past on the subject of worn compound and
cross-slide screws and nuts. I thought I'd share my work of the
weekend with you: I've got an old semi-worn-out 13" from 1946. When I
bought it last year I cleaned stripped, painted and fixed the worst
of the broken bits but I did not do anything about the worn screws.
The cross slide and the compound were very worn with the compound
the worst. No ACME form was showing except for 1/2" at the tip.
There was about 1/16" of compound movement when the gib was loose.
Shimmed up the dials to reduce backlash but it was still terrible
because the gib had to be so tight. So after a few months
occasionally thinking about it, I pulled out the old compound screw,
measured everything (it's a 1/2-10 RH with a 5/16-24 handle nut
thread) and here's the work I did. BTW, all work below was done on
the same 13" lathe. 1) Remade the entire shaft complete from 5/8"
W-1 drill rod. Took great care in the tool grinding, set up and
single-pointing of the ACME thread. Cuts were all 2 or 3 thou for
threading. Work was between centers and it never left the setup
until all shaft steps were turned to final size. It came out perfect
with exactly 0.050" tooth height and 0.010" tooth clearance. 2) The
bronze nut threads looked good to the eye so I thought I'd see how
it did with the new screw. 3) The hole in the threaded mounted
bushing (this is the one with the "0" index stamped on it) was very
loose on the shaft so I rebored/reamed it to 0.500". Made the new
shaft 0.499". 4) The mating faces of the threaded bushing and the
calibrated dial were grooved so I minimally refaced each about 20
thou, being careful to keep the face perpendicular to the bore. 5)
Adjusted the new shaft shoulders so that there is exactly 2 thou
between the handle and the calibrated dial when the handle nut is
pulled up tight. 6) Made new rounded, slotted handle nut to match SB
originals and a good solid tool for it (done on mill with 5C spin
index). Then I fitted it all up, and somebody's looking out for
small children and fools - it worked perfectly. The backlash is now
exactly 2 thou, the handle turns smoothly and evenly, the dial turns
smoothly without slop, and with the gib loose you cannot rock the
compound back and forth one iota. Not quite new but awfully close. I
got lucky that I still had a good nut but I wanted to relate that
this is a job that can be done in a weekend and the improvements can
range from good to great. This lathe will not hold 3 thou over 6
inches near the chuck but you can do good work if you know where
your machine's problems are. Another point: I think the bronze nut
and compound screw are the originals. The screw was completely worn
out but the nut was like new. Is this like lapping-where a softer
metal is the lap but the lap with grinding compound cuts the harder
work piece? If so, your nut may be better than you think. I'm not
ready to tackle the cross-slide yet because it's a telescoper for
the taper attachment and that's going to take considerably more
effort and time. Next up is a thread dial 'cause I'm getting tired
of waiting for the carriage to s-l-o-w-l-y traverse back. Ed
(25201) |
