| How to add QG gear box to C
model? (Sep 29, 2001) |
SB 9" double banjo (gear box
change over) (Dec 30, 2002) |
| "C" to" A" conversion
(Jan 13, 2002) |
9"
Conversion "C" to "A" (Feb 5, 2003) |
| C-to-A conversion gear info
(Jan 14, 2002) |
3rd
Hole For Gear Box (Feb 14, 2003) |
| Mounting of 9" gearbox
(Jan 23, 2002) |
Conversion SB9 model C to A (Feb 23, 2003) |
| C to A conversion (Feb
25, 2002) |
C to A Conversion Question
(Nov 21, 2003) |
| C to B to A Conversion
(Apr 22, 2002) |
Upgrading 10K from a B to an A?
(Dec 6, 2003) |
| Model C to model A (Aug
4, 2002) |
Converting model C to A using
model C apron? (Dec 30, 2003) |
| 9c upgrade (Sep 1, 2002) |
SB 9" lathe power feed upgrade
(Jan 19, 2004) |
| SB 9" Mod A Leadscrew
(Oct 2, 2002) |
Upgrading model C to A
(Jul 15, 2004) |
| Converting/rebuilding SB
A - Plating (Oct 7, 2002) |
Bert's C to A conversion
(Jul 25, 2004) |
| Some more upgrade questions
(Nov 6, 2002) |
MORE ? about 9" model C to A
(Aug 14, 2004) |
| Any Tips For "C" to "A"
Conversion? (Dec 22, 2002) |
9" Lead screw question
(converting c to a) (Aug 31, 2004) |
| 9c to 9a conversion (Dec
23, 2002) |
Contemplating a conversion from
9C to 9A (Jan 24, 2005) |
| |
| How to add QG gear box to C
model? |
| How much
other Stuff is required to add the QC gearbox to a model C, from
complete C in VG shape, thinking about buying the QC box but don't
know what changes to the gears and leadscrew would be needed. (1646) |
| I did it - really wasn't too bad. You
definitely have to change the leadscrew, it has a whole different
way of attaching. I found a good used one and put it on with the QC
box. Had to drill one new hole to help attach the gearbox (3 holes
in all, use old two and drill one new one.) Lining it all up was a
bit of a chore too, it gets critical when the carriage is all the
way left. A few shims above the gearbox solved that problem. I think
you could machine your old leadscrew to match the gearbox but then
what drives the lathe while you machine it! Leadscrew length is
approximately the same as you old lead screw minus about 8-9 inches
roughly. The interface to the gearbox from the spindle is done with
some of the change gears you already have. But its better to save
these and sell them later! When you find a QC gearbox ask for the
gears that go with it You start with a 20 (or 40) tooth, then an 80
tooth on the Y yoke. This 80 tooth has a double height hub. The 80
drives a 56 tooth on the gearbox input shaft. The shaft is longer
than 1 gear in thickness so you use to 40 tooth gear to take up the
space. For some unusual speeds you swap the 20 and 40 tooth gears as
specified on the speed plate. i.e. the 40 is used in the drive train
and the 20 is used as only a spacer. Check the SBL parts diagrams to
see how this all works out. I took the time to completely
disassemble the gearbox, clean it up, put in new felt wipers and
repainted it to match my lathe. Sounds like a lot of work but it
really went a lot easier then I imagined. Bill (1648) |
| Just been through
this whole fiasco. I'm not sure if this applies to all model C's
('39 appeared to be an odd year in terms of interchangeability) but
I had to replace the gear sector on the head end. The locking screw
boss on the sector that was on my lathe would not clear the gearbox
and prevented engagement of the geartrain. Bummer. I definitely
think the QC box is worth the effort though. Frank
(1650) |
| There are a couple of
things you have to do in order to convert a model "C" lathe over to
a model "A." But first, for the benefit of those who might not know
the difference between the three basic models, a brief description
of their features and differences: 1) The model "A" lathes have the
Quick Change gearbox and power feeds on the apron (via a clutch) for
both longitudinal and cross feeds as well as the half nuts. 2) The
model "B" lathes are Change Gear (or "Pick Gear" lathes as I'm used
to calling them) but do have the longitudinal and cross feed plus
half nuts (like the model "A"). 3) The model "C" lathes are Change
Gear lathes with the basic (simple) apron that has half nuts only
(no clutch on the apron and no power feeds). Now, both "A" and "B"
lathes have a longitudinal keyway cut the length of the leadscrew in
order to power the drive mechanism in their aprons. Model "C" lathes
on the other hand, do not. So, to convert a model "C" to an model
"A" requires mounting a gearbox (and drilling and counter boring the
third mounting screw hole as William mentioned), converting the
leadscrew (if you don't get one with the gearbox), and changing the
apron so that you can have the power feeds (that's why you want to
convert it, right?). Without changing the apron, you will only have
longitudinal feed via the half nuts only. But you don't need the
longitudinal keyway in the leadscrew if you use the simple (model
"C") apron. In that case, all that needs to be done to the leadscrew
is to shorten and adapt it for the gearbox. Webb (1652) |
| "C" to "A"
conversion |
| I scored a
deal on a Model "A" gearbox and leadscrew. It's a two-lever gearbox
with no top lever and apparently no 'sliding gear'. Researching the
SB company website, exploded pix of subassemblies in two different
parts manuals and pix of complete assemblies on eBay, and what else
I can find, only leaves one totally unanswered question of the four
that came up: 1] Since my old Model "C" has the non-detented
tumble-reverse mechanism and two same-size tumbler gears, can I use
this reverser with the new setup? apparently yes; there are pix of
Model "A" headstocks with the non-detented reverser. 2] The late
parts book shows a 20t stud gear, I know I have to obtain this
separately. 3] The gear that SB calles the 'reverse gear', the gear
that goes on the same shaft as the stud gear, the gear that is
driven by the tumbler-gears, has 24 teeth on my lathe but shows in
the newer parts book as p/n PT28NK1 with no tooth count specified.
Do I have to change this to a 28t gear? It would seem unlikely,
manufacturing economies dictate the fewer parts the better. 4] If
the answer to [3] is "yes", then do I have to change the reverser
itself? It would seem so since a larger reverse gear means different
shaft centerlines between the reverse gear and the front tumbler
gear. (2698) |
| I also just scored
a QC gearbox. This one comes with all accoutrements including the
lead screw for a 3 and 1/2 foot lathe. The trouble is my "C" is a 4
footer. Does anyone have the opposite of my problem? I'd like to
trade my 3 and 1/2 foot lead screw for a 4 foot one. Glen
(2706) |
| Can't help you with
the leadscrew, my 9" C is a 42-incher and that's the QC setup I
scored...but I would appreciate knowing how many teeth are on the
driven gear [on the same shaft as the stud gear] on your "A". (2707) |
| I just scored a
Gear box off of a heavy 10 SB. Will this fit a 9? What needs to be
done to the end of the leadscrew that goes into the gear box? What
is the proper gear train the goes on the banjo? Do I need a single
or double banjo? Gerald
(2708) |
| For all I know the
'A' model so-called 'reverse gear' p/n PT28NK1 could very well be a
24t gear just like on a "C" model [and manufacturing economies would
suggest that, else there'd be two different tumbler-reverse
brackets, etc in the system]; PT55NK1 is a tailstock, PT82NK1 is a
knob and PT54NK1 is a spindle, and the series goes all the way up to
at least PT486NK1 so I'm not sure the '28' in the p/n has anything
to do with the # of teeth; I think it's just a sequential p/n. the
20t gear can always be bought from south bend, I would guess about
$40-50, I'll be calling for a quote and I'm going to be looking into
other sources, gear vendors who might not call it a south bend gear
per se, just a __-tooth gear of __ bore size and __ diameter and __
tooth pressure angle...if I can assemble all those specs...difficult
since it's been about 25 years since I had to know what any of them
meant. (2709) |
| I wonder if a
shorter change-gear lead screw could be adapted for use on a longer
QC lead screw machine and vice-versa? Paul R. (2714) |
| C-to-A
conversion gear info |
| p/n PT28NK1, the
'reverse gear' for the "A", is $68 [!!!] from SBL. I still don't
know how many teeth this gear is supposed to have. This is the gear
that goes on the same shaft as the stud gear. As to the 20t stud
gear needed with a QC box, I'm at work as I write this and my lathe
and it's gears are at home, but my preliminary cruising through the
McMaster-Carr catalog looks like the right 20t gear is probably
[don't quote me on this, I have to take some measurements and verify
first] p/n 6325K15, 20t, 16 pitch, 14.5 degree pressure angle, 1/2"
bore, 1.25" pitch diameter or maybe p/n 6325K83, 20t, 20 pitch, 14.5
degree pressure angle, 3/8" bore, 1" pitch diameter These prices are
for plain bore, figure about double that for finished bore with
keyway. It would really help if SOMEONE with a model "A" could
measure the OD and count the teeth on their 'reverse gear' as SBL
calls it, for all of us converting. use on a accoutrements is
problem?
(2718) |
| The gear on the
same shaft as the 20 tooth stud gear has 24 teeth. The dimensions
are determined by the teeth on the spindle since it meshes with the
two reversing gears which mesh with the spindle. The spindles are
the same therefore the gear in question is the same. I took the
reversing lever off my "A" (detent type) and fitted the reversing
lever from my "C" (locking nut type). Except for some difficulty
getting it past the gear guard on the gear box it would appear to
work. Glen (2722) |
| This
tells me the only modification to the headstock needed is the
addition of a 20t stud gear which Scott may be providing
affordably. (2748) |
| Perhaps someone
could enlighten us newbies as to the difference between a SB model A
versus the model C and what this new gear would do for us. Gary
(2749) |
| The
difference between the A, B and C models are: C model : power feed
on the Z axis (length wise) done by replacing (changing) gears to
achieve feed rates and threading pitch. B model: same as C, but
additionally has a power feed on the cross slide (X axis). You would
need the apron from and A or B lathe to upgrade a C lathe to a B
lathe. Also needed would be the leadscrew from a B or the C's
leadscrew slotted. A model: The A model has a Quick Change gear box,
Just move some levers to change the feedrate or threading pitch.
There are two types on QC boxes. The single lever and daul lever.
The daul lever is much more desirable. The QC boxes generally cost
around $200. This is a ball park figure. As you can see from this
continuing thread, there are a few more parts involved than just the
QC box. The lead screw is different on the one end. The bed has to
be drilled for an extra hole. And there is a different gear
arrangement on the back of the lathe. From all this you get a more
convenient lathe, that is faster to change feeds and threads than
having to change out the gears at the back of the lathe. Tom(2750) |
| Mounting of 9"
gearbox |
| Apparently
converting a Model C to receive a gearbox requires drilling a
mounting hole in the bed. Does this require a special bit due to
material hardness or am I essentially just drilling cast iron?
(2906) |
| I hadn't
thought of that and it's something I need to know before I start
drilling. Cast iron can be pretty damn hard stuff if treated right.
Hopefully someone here knows. (2910) |
| I haven't drilled
any of the South Bend beds as of yet. From what I have been told
most of them are not hardened. I was told that the hardened beds have
an 'X' in the serial number. I might be mistaken on the letter
though. Tom(2912) |
| My largest concern
would be that the hole is partly in the front V way - i.e., you have
to drill into a non-flat surface. It may be the the bore itself is
entirely in the flat and only the counterbore for the head goes into
the V-way. If so, that hints at a method - drill the main bore, then
use it to guide a counterbore which would cut into the side of the V
way. It would be nice if one had a milling machine big enough to put
the bed on. Another option would be too flip it over and drill from
the bottom - but it could be tricky to do that without taking the
headstock off the bed, which is if I understand not something to be
done lightly given the need to realign it precisely. Chris (2913) |
| Well, there's no
letter in my s/n...ain't but one way to find out. Will let everyone
know.
(2914) |
| Actually, the v-way
at that exact spot isn't used for anything, right? It's not like the
hole goes in the part of the bed where the carriage travels. perhaps
a flat-end carbide burr in a die grinder? On a different note, isn't
the headstock supposed to self-aligning on the v-ways? I can't
believe they would have gotten into a situation requiring
hand-scraping and -shimming for alignment in a production
environment. This could indeed get into a whole other realm of all
the various other ways to fasten them together...if the hole is
accessible from inside the gearbox perhaps a stud in the bed and a
nut inside the gearbox [cotter-keyed so it doesn't fall in the
gears, of course]. A v-way clamp [like the one that will no longer
be used to mount the motor controller after the conversion] somehow
supporting the gearbox from the outside? I haven't started my
conversion yet, love to hear from someone who has already done this.
Lurch (2915) |
| Come to think of
it, if this were a hardened bed I doubt it would be as full of crash
marks on the inner ways right under the chuck as it is. (2916) |
| I wouldn't bet on a
hardened ways not being buggered up. Someone always finds a way. I
would think yours is probably not a hardened ways as it is a C model
and also probably an older lathe. From what I was told hardened beds
were rare on the older lathes. If I were to do this job, I would
drill a hole smaller or pilot hole, then drill to size. With
hardened parts, I've had better results by first drilling with some
smaller drills. Next, I'd look at a piloted counter bore. You might
make a rougher and a finish diameter if looks are a concern. I'm
more concerned about the cutting action due to the 'V' way. I doubt
overall it would matter as far as function though. Tom (2918) |
| You could grind a small flat, drill, then counterbore. Headstocks are fitted to the lathe by scraping. If you
find shims under the headstock look out, it tends to mean that
someone has had it off and either didn't know what they were doing,
or that the lathe was such a beater that only shimming could get it
into line. Stan (2921) |
| Gotcha. If I read
you right, when things are right with the lathe, and it's the same
headstock that went with that bed originally, I can remove it and
replace it, and it will index [if that's the right word] on the ways
and end up in the same place, right? (2922) |
| Brian; Right you
are. The headstock will go back onto it's bed and line right up,
just as the carriage will. In all reality, the beds tend to be
ground with such repeatability that the
headstocks/tailstocks/carriages tend to be interchangeable within a
given lathe series. Odds are our model C headstocks could be swapped
and be fine. Any variation tends to be so minor as to fade into the
background noise. On the smaller production lathes I couldn't say if
SB fitted the headstock to the exact lathe, or fitted them to a
master fixture and simply verified that the alignment was within
allowable tolerance after each lathe was assembled. Stan (2923) |
| Any one have an
extra 3 foot bed for a 9 inch SB for sale? I know a lot of people
upgrade to longer beds when they can afford it but I am limited in
space so a 3 foot does me real well. Gerald
(2925) |
| From what I know of
production flow, the latter is more likely...that way they can build
headstocks till they have so many stockpiled, then build
beds. (2926) |
| Gerald, What bed
length do you have now? I have a 3ft. bed on a 9 inch C lathe. It is
in real good shape. Maybe work something out. Tom (2930) |
| Brian, Well, I've
done it and it's not that big a problem. The ways on my '39 are not
hard, so it machines like really nice cast iron. I strapped my bed
down on a Bridgeport, lined everything up, and machined the
counterbore with an end mill. This gave a nice flat surface to drill
from. The only thing I ran into aligning the headstock was that the
gears on the left end must line up with the gearbox and sector arm.
(Sorry, no picture of me standing there at 4AM thinking my headstock
was suddenly too short G You may also find, as I did, that the
sector arm locking bolt will not clear the gearbox. I swiped the one
off my dad's A model and sure enough the lug sits about 25 deg
higher on the casting. (2969) |
| I'm glad I got a
new sector arm with the gearbox then. I take it you had to readjust
your headstock a little farther away from the tailstock during the
conversion? I guess I need to disassemble it completely and take the
bed to someone with a Bridgeport. No big hassle; I've had it apart
and back together enough that the two bolts under the headstock
aren't much more work chuckle (2982) |
| C to A
conversion |
| Does any body have
a lead screw for a 9" x 4 foot "A" lying around? I am about to start
milling a groove in my old "C" lead screw but if someone had an
extra it would simplify things. I have a 3 and 1/2 foot "A" lead
screw to trade. Glen (3370) |
| I have a model A
leadscrew that is from end to end 38.5 inches long. Is that the
correct one for your lathe? It came with a 4ft cabinet 9 inch lathe
I took it in the shorts on. Gerald (3378) |
| Gerald, No, the
lead screw I have from a 3 1/2' lathe is about 38 1/2" long. I need
one about 44 1/2" long. You had me all excited 'till I ran
downstairs with the tape measure. Glen
(3379) |
| Glen. Sorry I cant
help you then. I guess I will use it in my conversion I am going to
do. I went to southern Iowa Sunday and pick up a 3.5 model C and I
will use it on that conversion to a model A. I am gonna sell off the
extra parts on Ebay from the 3 SB 9's that I have. That will leave
me with a complete 3 foot model C with all the change gears and a
3.5 Model A. I got a real surprise with the 3.5 I just got. It was
very ugly and covered with thick rust when I got it but a little
elbow grease and a brass chore girl pad and all the rust ended up
being on top of the very nice and just slightly worn ways of the
bed. I tore the headstock apart tonight and was so happy to find a
unscarred spindle. I still need to figure out a way to mount my
heavy 10 gearbox on a 9. Might use the bed from the cabinet 9 I
bought to do some preliminary measuring and milling to see if it
will fit. Gerald (3381) |
| Did you know
that you cannot just convert a model C carriage to a model A by
sliding in a model A leadscrew. I just found that out tonight and I
guess I will go into work tomorrow and see if I can find a .700
reamer to open up the holes in the casting where the power feed gear
is at. Hopefully tomorrow the headstock and the bed will be going
ingot the hot tank to get a good bathing and to wash the accumulated
Sherwin Williams off it. I did order a new gasket for the backside
of the compound and two new spring loaded felt oilers for the
headstock today from SB. I think the oilers are gold plated at $11
each but the ones that were in it had a indefinable substance in
them and I wasn't going to take any chances. Any one have a extra
set of guts for a thread indicator? Some how, the one I got is
nothing but the cast iron. Are there anymore little surprises in
store for me during this conversion? Does anybody know the distance
between the bolt holes on the gear box? I know I can just measure
them but it is out in the garage. Gerald (3462) |
| C to B to A
Conversion |
| I am
half way through the conversion process. I milled a keyway in the
leadscrew for my 9" x 4' C and changed out the apron to a clutch
type with power cross feed that I got on E-bay. I had the leadscrew
here at work for several weeks waiting for our machinist to help me
but he could never get around to it. I finally took matters into my
own hands. I made a milling attachment from a Taig headstock, a DC
motor from a treadmill and a dimmer switch with a full wave
rectifier bridge. The Taig headstock is just the right height to
match the center of the SB when mounted on the cross slide. Not
having a steady rest, I made one out of a 2 x 4 mounted on the base
for the tailstock. I drilled for a tight fit with a bit mounted in
the lathe chuck. I cross drilled the 2 x 4 for a setscrew to keep
the leadscrew from turning when I had to rechuck it to take another
pass with the mill. The chuck was clamped to the lathe bed by
propping a piece of scrap steel under one of the lathe jaws. I took
the precaution of unplugging the lathe motor. It is just too much of
a conditioned response to grab the F/R switch when you want to start
cutting. The next step is to cut down the length of the leadscrew,
thread it and cut the keyway for the drive gear. Does anyone know
how the sleeve is affixed to the leadscrew? The documentation from
SB says there should be a pin, but I can't find one.
(4026) |
| It's taper pinned
on there, it's just a b***h to find. Apparently they drive in the
pin and then file it flush. A good light and a magnifying glass
helps. Frank (4028) |
| Frank, I
spent about a half hour looking for the pin under a 40 power stereo
microscope with a fiber optic light source and I still couldn't find
it. I tried magnetizing the shaft and dipping it into a pile of
filings to look for anomalies in the flux lines. I tried soaking it
in vinegar to see if the pin would etch differently than the collar.
I think that the pin healed itself into the collar. I ended up
making a new collar and a new pin. The good news is that I finished
the conversion. I now have a 9" x 4 foot A as well as my original 9"
x 3 1/2 foot A. I also have a some leftover C parts (apron,
leadscrew,
etc.) that are available to whoever might have a need. Glen (4082) |
| Would you
have an extra pair of half nuts? I could use a pair so I don't have
to repair mine. Gerald
(4083) |
| Gerald, The
model "A" apron I bought on eBay had excellent half nuts, so the
ones I refurbished are not needed. I spent about 6 to 8 hours
building the holding fixture described in the HSM article and
learning how to braze cast iron. I found that furnace patching
cement is useful in building a dam to keep the brass from running
out of the area to be repaired. If you send me your old half nuts I
will send you a "renewed" set for $25.00 S H included. I tried them
out on my lathe while still in the "B" configuration and the only
play I could detect was due to the leadscrew shifting in its
bracket. There is a difference between model "C" halfnuts and those
for B or A lathes. The interlock mechanism that prevents the clutch
drive from being engaged when the half nuts are engaged and vise
versa depends on an adjustment (filing or grinding) of a perjoggin
on the side of the bottom half nut. These "C" half nuts would need
to be fitted to your "A" or "B" lathe. Cheers! Glen (4085) |
| Yep I
found that out when I did my conversion form C to A. I will see if I
can find the wore out set. Gerald (4087) |
| Model C to
model A |
| What all do I
need to convert a Model C to a Model A? Gear box, and what else?
Clint (5579) |
| Clint,
Congratulations. I see you got that gearbox I had on my watch list.
See if you can get the lead screw from the same vendor if he has it
and if the lathe it came from is the same length or longer than your
lathe. You can modify your old leadscrew but it means cutting a
keyway the whole length of the screw. I did it but it was a pain in
the butt. I still have the lead screw that I got with my gear box.
It was for a 42 inch bed. If it will help you it's available for a
very reasonable price. E-mail me off list. You will need an apron
from an "A" that has a clutch and a lever to switch between cross
feed drive and lengthwise drive. You may need a cross slide lead
screw that has a gear to be driven by the worm gear in the new apron
you will acquire. And you may need to mill out an opening in the
bottom of the saddle for access to the new cross slide lead screw.
Neither of these were necessary on my "C" but I think that mine was
a "Frankenlathe" with parts from several different donor lathes. You
will also have to drill one more hole in the bed to mount your new
gearbox. Mine already had the third hole which is another reason I
think I have a hybrid. Glen (5584) |
| Glen Sounds like it
may be a big job? Do you think it is worth it? You have me a little
confused on the cross feed drive and length drive. Are you saying
that if I do that it will have a power cross feed. Do you know of a
site, etc that I can look at that shows what all is involved in
converting? I may need to take you up on the lead screw, I suppose
it can be cut down to work on the shorter bed? I also am looking at
a 48 in bed. Any help on this will be appreciated. Clint (5585) |
| Clint, The 9"/10K
Parts Manual in pdf Format that you can download shows the parts
differences between the A, B, and C SB Lathes with enough detail to
see the Apron Parts Glen mentioned in his prior post.
Jim (5587) |
| Jim, I
downloaded that last night, I have not even looked at it. To be
honest, I did not eve think to look in it for the differences.
Clint (5588) |
| Clint, I think it
was worth the effort. How long is your lathe bed? Mine is 48 inches
which is why I had to rework my old lead screw. There were lots of
model A lead screws around for 42 inch lathes but I couldn't find
one for the longer bed. The cross feed drive is the difference
between the C model and the B model. Look at the manual to see the
parts difference. Basically the lead screw has a keyway to run a
worm gear in the apron that turns the cross slide lead screw to move
the tool in a facing operation. The difference between a B and an A
is the gear box. There are a couple of other critical parts for the
A conversion that I forgot to mention. You need the output gear that
fastens to the lead screw head end which should be included with the
gearbox. I don't have an extra one of these, so make sure you get it
from the gear box seller. You need a 20 tooth gear for the stud gear
to make the thread pitches stamped on the gearbox work out right. I
was lucky and got both of those with the gearbox I bought, but
several others on the list have not been so lucky. I'll send you my
home phone number (offlist of course) if you need talking through
all of this you can call me at home this evening. One more thing. I
saw that grumpytool had an apron casting listed and as a separate
item apron parts. The price was cheap last I looked, but not all of
the parts are there. Bid on this for spare parts if you want but
don't pay a big price for it because you will have to buy another
one anyway. Cheers! Glen (5590) |
| Clint, Another
thought for you: I have a 9" model C with 3 ft. bed. I was doing a
lot of threading so I purchased a used quick change gear box. It
came with the 20 tooth gear and necessitated shortening my existing
lead screw, turning the gear box end of the lead screw to accept the
20 tooth gear, cutting a keyway for the gear and drilling and
tapping the end of the shaft to insert a socket head cap screw and
washer to hold the 20 tooth gear on. The mounting holes for the gear
box were already existing in my machine so mounting was a snap. I
now have power longitudinal feed and quick change gear cutting
capability but I do not have power cross fee which I have no real
use for anyway. I'm happy as a lark and I didn't have to find a new
lead screw or cut a keyway in mine and I didn't have to replace or
mess with my apron. I suppose if one were doing a lot of large
diameter work maybe power cross feed would be nice but for the shaft
work and small turnings I do longitudinal feed is fantastic and
power cross feed would very seldom be used. Of course I was very use
to hand feeding in both directions prior to the Q.C. gear box and
what I now have is such an improvement that the lack of power cross
feed is insignificant. Neil B. (5599) |
| G'Day Clint, I know
of a good site! It's called Southbendlathe on Yahoo groups. Try:
http://groups.yahoo.com/group/southbendlathe/files/9%22%20Conversion/
There is a wealth of knowledge in our very own 'Files' area. Bill
(5640) |
| 9c upgrade |
| Upgrading my 4 1/2
ft bed 9c to a b. only lacking is my 4 1/2 ft leadscrew is it
possible/feasible/cost effective to have my very good leadscrew
machined 42 in with the proper slot/ keyway. rick
(6115) |
| Are there really other lathe forums? Can you list them
please? I need ALL the help I can get. Philip (6138) |
| Here's a
way to cut a keyway in a leadscrew in a lathe. If you have a steady
rest you can probably skip this step. Make an L shaped bracket from
two pieces of 2x4 lumber screwed and glued together. Chisel out a
hole to fit over the centering "bump" on the tailstock base casting.
Cut a groove in the bottom of the 2x4 L bracket to fit over the
slide feature in the tailstock base casting. Cross drill the L
bracket to accept centering screws like the tailstock has. Drill a
hole through the bottom 2x4 to accept the tailstock mounting bolt.
Mount a 3/4" drill bit in the headstock and drill through the
upright 2x4. Cross drill the upright 2x4 for a "set screw" to keep
the leadscrew from turning. Mount a Taig headstock and motor
assembly on the cross slide. Taig gave me a short piece of the
aluminum dovetail when I bought the headstock. I turned a spud to
fit the cross slide opening and bolted the dovetail to it. The Taig
spindle center height came out right at the South Bend spindle
center height. Use a collet to mount an end mill. Remove the collar
from the leadscrew so that the leadscrew will pass through the
spindle. The collar is pinned to the leadscrew with a taper pin. If
you are also going to add a QC gear box you can cut the leadscrew
off right behind the collar. Unplug the AC to the lathe. The
temptation to turn on the power is too great in the following steps.
Chuck the leadscrew in the lathe and stop the spindle rotation by
putting a prop between the chuck jaws and the ways. Use your home
made steady to support the other end. Mill the keyway. You will have
to alternately loosen the chuck and the wooden steady set screw to
move the leadscrew through the spindle because there isn't enough
travel to do the whole thing at once. This worked for me. It
occurred
to me later that my Sherline milling column would have worked, too.
I made a Sherline mounting adapter to fit the cross slide. This is
actually more flexible to use because you have the z axis from the
milling column in addition to the lathe x and y. Those of you who
are lucky enough to have tool post grinders will not need to make
your own lathe mills. Glen (6160) |
| Glen I have a
Homier mini mill, how would be the best way on it? I am going to cut
a key way on a Mod C screw so I can mount a power cross feed, and
leave the change gears the way that they are. Clint (6169) |
| Clint, I don't
know how your Homier mill mounts the column to the rest of the mill.
The thing you have to accomplish is to copy the mounting feature on
the bottom of a compound slide. Turn a piece of steel with a taper
to be grasped by the two set screws on the cross slide. Measure your
compound base for dimensions. If you can figure out how to do that
and pick up the tapped hole in the top of the cross slide for
additional rigidity, all the better. Then duplicate the mounting
feature that the milling column needs. Measure the mill base for
dimensions. I'll try to post a picture of the Sherline adapter and
my Taig "tool post mill". Glen (6175) |
| Clint, The main
problem I would see doing it on the Homier is table travel of around
9 inches. If the table length was longer than the lead screw, such
as a Bridgeport, then I'd lay the lead screw in the T-slot and clamp
down with some bar clamps. This is pretty standard setup stuff on a
Bridgeport, but you don't have one. What I would try is get some
dowel pins that will fit snug in the T-slots. You will need at least
two, more(4) would be better. You will need at least two V-blocks,
more(4) would be better, of the same size. You will need to keep the
orientation of the slot constant. Here it goes: Put or wedge the 2
or more dowel pins in the T-slots (it should be a snug fit). You will
leave these in place for keeping the center of the slot. You can
move them if necessary to contact the V-blocks. Next Space the
V-block the same distance as the dowel pins. Slide them up to one
side of the dowel pin (same side all the V-blocks). Lay the lead
screw into the V-blocks. Place some piece of copper stock( a penny
will do) between whatever clap the V-block has and the lead screw,
to protect its finish and help in clamping. Tighten the clamps of
the V-blocks on the leadscrew, never undo all the clamps to the
v-blocks, this is what is keeping the slot aligned. Make sure the
V-block are tight up against the dowel pins. Clamp the V-blocks and
lead screw to the table with bar strap clamps to the table, use a
piece of copper again. I would use at least 4 V-blocks. Next center
the spindle in the middle of the lead screw. I would get an endmill
that is at least .010 to .020 undersized. Mill out a slot down to
depth with this endmill, maybe leaving .005 to finish the bottom.
Usually, the endmill will pull to one side, so that is why you will
need to go through with one that is undersized. You have the option
of roughing out the slot the entire length or finishing it along
each length. IE you will be doing the slot in 8 or 9 inches at a
time. As you cut along you will need to unclamp and reclamp the
V-blocks and Strap clamps. Actually you might want two strap clamps
per V-Blocks. Keep one undone till your close to the clampe one,
then clamp the other on and undo the other. As you get done on one
section of 8 inches, then you will need to move the V-block down to
the next section. Remember keep at least one of the V-blocks clamped
, by its clamp and not the strap clamp) to keep the alignment. Keep
repeating this cycle, till the length is done. This isn't easy, so
go slow and take light cuts, so .020 depth per pass. You can do the
sections at a time between each V-block for the roughing. I'd
probably do the roughing first, since a small amount of
misalignment can be corrected. I am not sure how much clearance
there should be between the key and the slot. I would say .002-.005,
but maybe someone else knows for sure. I would practice this on a
piece of round stock. You will probably notice that the cutter pulls
into the stock. You might have to compensate for this with a bit of
not feeding the table in that direction all the way. Also be aware
that the cutter with cut differently between climp milling and
conventional. Tom
(6176) |
| Clint, I know this
doesn't help but it's a shame I don't have my 16" shaper running
yet. Cutting keyways is shafting is something this particular shaper
was designed for, it has a 4" bore right thru the center of the
machine to accept any length of shaft, your leadscrew would be an
easy one. Unfortunately I don't expect to run it until springtime
when I've has the winter to clean it out and reoil everything that's
gummed up in the 50 or so years since it was last used G upgrade if
I ever run across someone *else* upgrading a SB. Dave (6177) |
| Clint, Steve Brown
was nice enough to convert my Sherline adapter photo and post it in
the Photo section under Glen's Accessories. Glen (6239) |
| SB 9" Mod A
Leadscrew |
| I am going the
upgrade one of my SB mod C to an A 3'Bed I have been waiting a month
for a mod A lead screw and it finally came in today. The seller sold
me the screw for a 3' Bed and it seems to be aprox. 4-5" to long, I
am assuming that this screw must have come off a 3 1/2'Bed. I
contacted the guy and he said that that is the only one he had and
no claims that I never specified the length, even though I save my
email correspondence between him and I and my mail requesting the 3'
is correct and his listed pricing per item listed the 3'leadscrew.
It does not look like I will get any further with the guy. Now, I
suppose it is possible to just cut this one down to the correct link
by turning the right side end down to size at the correct length and
then cutting off the excess, Is this the correct way to look at it?
Does any one know where I could get the dimensions of the overall
length, etc. of doing this I also bought an extra Mod C leadscrew (
in case I screw up! ) an want to cut a key way to convert my other
Mod C to a power cross feed. Does any one know where I can get the
info. for dimensions on where the key way runs, length, etc.? Any
help will be helpful. Remember I am new to machining so be easy on
me. I think both of these little projects will be a good learning
experience for me, and should be some good machining experience My
mod C is functional now and I also have the Speedway Mini Mill to
machine with. Clint (6530) |
| My model A is
missing the whole drive train. As a make do, I'm looking at putting
in an electric driven lead screw. Can you tell me the source and
price for your leadscrew? From a literature search I think it is
3/4" x 8, right hand thread. Is this correct and is it a standard
ACME thread? McMaster Carr has both leadscrew and threaded rod in
this spec. Does anyone have an opinion on using threaded rod vs
"leadscrew" material? John (6534) |
| I paid 50.00 for
the leadscrew, but it was used and I do not know if I want to
recommend him now. If you still want to try him, I will send you his
email. What size bed do you have, if you have the 3 1/2' and you
find a 3" I will trade. Clint(6536) |
| Clint, I have a 3'
Model C leadscrew (does not have the keyway) which measures 39 3/8"
actual length. Included with it would be the left end mounting
bracket (headstock end) if you need it. It may have a slight bend
near the right end which should not present a problem and/or could
probably be taken out easily. I'll let you have it for $50 including
shipping. Neil (6542) |
| Neil I have 3 of
the model C screws, it is the 3' Mod A screw that I need. They sent
me a 3 1/2' Mod A screw instead. Clint (6547) |
| Have my 9" S/B 36"
bed apart for gearbox repairs. The leadscrew with the keyway is 32
3/8" over all length. For reference the lathe S/N is 27619 NAR 9. If
further particulars are needed, just holler. Before I put some new
teeth on one of those gears, does anyone out there have any spare
gears? The one in question HAD 32 teeth, is 2 1/8" dia, 1/4" thick,
7/8" bore ( comes with a smaller press fitted re-useable gear 16
teeth, 7/16 wide and a final 5/8" bore through both pieces.) Chester
(6564) |
| Chester, I
do not have any extra gears for the gear box, look on ebay do a
search for South Bend in metal working look for a seller Ford9in.
Clint (6570) |
| Clint, I had the
same problem and cut it back with no problem. final length is not
critical, as the gear box holds the Left hand side in position. A
little too long is fine, but a little too short (in overall length)
is a problem. need, They dent me a 3 1/2' Mod A screw instead
measures 39 3/8" actual length. Included with it would be the left
end mounting bracket (headstock end) if you need it. It may have a
slight bend near the right end which should not present a problem
and/or could probably be taken out easily. I'll let you have it for
$50 including shipping. (6685) |
| Clint et.al. It is
very easy to cut down a leadscrew. The 3/4" screw will pass through
the spindle of your lathe, so all you have to do is chuck it in the
lathe and turn down the end that gets supported by the babbit
bearing. Take the bearing off and use it to check the fit. I have an
extra leadscrew for a 3 and 1/2 foot model A. I think I already
offered it to you a couple of months ago, but you weren't ready to
try cutting it down, yet. Glen (6686) |
|
Come to think
of it, I saw a project somewhere to add a handwheel to the end of a
leadscrew. It would be a neat feature to have for threading, etc.
Don't cut off all of the extra length. Save enough to mount a
handwheel. Glen (6687) |
| Be aware that you
need to support the end that sicks out of the headstock on the left
side. If its to long of a piece, it can bend or whip around. Best
result is a damaged part, worst I've seen is a broken hand.
Tom (6690) |
| I cut my 3 1/2'
leadscrew down to fit the 3' bed, no problem in doing so, looks
factory. This is the first precision cut I have done and very happy
with the results. The next challenge is cutting a keyway in a mod C
screw to convert to power cross feed. I am almost done with my Mod A
conversion and getting ready to restore and convert my other 9" to a
Mod B I will post some pictures this week. Clint (6692) |
| Glen That is an
excellent ideal, but to late on this screw . I might try this on the
other lathe I will be doing next. Clint (6693) |
| Converting/rebuilding SB A - Plating |
| Converting and
rebuilding SB mod A I have been working on one of my SB lathes, the
one I am converting to an A Man! To do a real paint and full
cleaning is a big job, so far I have spent 4 afternoons, and I still
have the headstock and QC box to clean up and paint. I have the bed,
tailstock, carriage, apron, compound, and wrenches cleaned up and
painted. I plated some handle this afternoon, which I am attaching a
picture of them. I did not have time to get the wheel handles
plated, as it was 1:30 tonight before I got through with these, I
have them soaking in a cleaning solution with lye, TSP, and some
other cleaners, this will insure all the oils from the pores is
removed, metal will not take a plate where any type of oils are
present, even your finger prints will not plate. Anyway, I plan to
finish up the other handle tomorrow if I can, I will have to go in
to the Day Surgery tomorrow and let them put me to sleep, and inject
crap into my spine areas. If I feel like it I will finish this up
afterwards, if not I will do it Tuesday. Dang Doctors, interfering
with my progress, I guess I could bring with me a couple of rough
parts and sand paper, Work on that while they get me ready? There is
a lot more work to doing a full restore on a lathe than what it
looks like. I sure dug out a part of history from the model A
carriage when I dismantled it, it is clean and painted now. Ii
thought about plating one of my 3 jaw chucks, should I do it? Clint
(6577) |
| Didn't get the
picture. I am curious about the possibility of do it your self
plating. Just you practice / cost effective is it to do plating your
self? I see the stuff to do it for sale and I have wondered just
what it takes to do a real good plating job on your own. You
obviously have the skills so what is involved? Yasmiin (6579) |
| Yasmiin Yes, I do
the plating myself, I have a small hobby plating shop. The cost can
be quiet expensive to set, depending how large a setup you want. To
get things plated can really be expensive. There are a lot of
variables to plating, it takes a little study work, but is not that
complicated if you can pay attention to detail and have patience. I
am a moderator of the yahoo electroplating group. Join up and you
can learn a great deal there. Stay away from the kits and suppliers
for plating chems. most of them are big rip off artists. There is no
such thing as buy a kit and start plating. This is a big lie. If you
get into it you will soon see what I am talking about. I buy my own
chems. and mix my own baths. But like I said there is more to it
than having a copper plating bath, so many variables. I look forward
to you over there, just give me a shout once their.
http://www.groups.yahoo.com/group/electroplating.
Clint (6592) |
| Some more
upgrade questions |
| When installing a
qc gearbox, what better time to restore/clean/strip and paint
it. After removing my headstock and comparing it to the parts
breakdown illustrations. I discovered i was missing #s 16,17,22 and
23. shims,2 solid and 2 laminated. I ordered from LeBlond along with
capillary oilers and thrust bearing. my question. do both sets of
shims go on the front side of the bed, front and rear of the
headstock. that is my take of the parts break down. when I receive
the thrust bearing ($31.00 from LeBlond) will take it to the local
bearing place and cross reference part #. will post my
findings. rick (7033) |
| You may find if you
have their laminated shims, after peeling them to the right thickness
you may not need the solid shims at all. Or maybe the idea is use
the laminated shim as a sort of feeler gauge then surface-grind the
solid ones to the same thickness? I'm going through the same deal
right now...I have the solid shims, the laminated ones are on their
way, and the homemade ones I pulled out of there are in the dumpster
where they belong. I don't know how one could put a shim on teh
backside of a non-separate-cap headstock--no slot for it. (7034) |
| Any Tips For
"C" to "A" Conversion? |
| I finally obtained
all the items need to convert my "Workshop Precision" to an "A."
I've read the info in the files section, however, since I'm just
learning metalworking, I'm concerned that I might mess up on
drilling the third hole for mounting the gearbox to the bed. My plan
is to remove the head stock, mount the bed on my RF31, then drill
from the bottom through to the top. Is there a better or easier
method? John
(8208) |
| What if you used an
end mill to make a flat on top where the hole has to go first? That
way you wouldn't need to be concerned with the drill wanting to walk
at break-through. (8209) |
| Good
point. I hadn't considered that, but will do it. Having milled a
flat on top, will it matter whether I drill from the top or bottom? John (8214) |
| I don't see why it
should but you may want to throw this question past someone more
experienced than me. (8223) |
| 9c to 9a
conversion |
| John I made a
template to locate the third hole along the v-way and carefully
measured its location. when I was satisfied it was correct I used a
counterbore with pilot as this will correctly center the final
drilled hole. be sure and go slow and use plenty of fluid. rick (8241) |
| If I
understand it, you used the template to locate the hole, drilled a
pilot hole from the top down, then counter- bored. If that's it, it
makes sense. Just real scary for one who lacks skill, ability, and
experience. It does, however, seem fairly straight-forward, so we'll
give it a go. I don't expect the gear box to arrive for about a week
or so, but I'll let you guys know how it turns out.
John (8243) |
| Look at it this
way--if the flat you create is a little oversize, it can't hurt
anything--nothing indexes there, unless you run the saddle up by the
headstock and then the saddle is supported it's entire length
anyway. Me, I'm a perfectionist anyway, but it's nice to know I have
margin for error. If it were my bed, I'd set it up on the mill [if I
had a mill], indicate it in so I knew it was parallel to the x-axis,
put a pin in the quill that barely squeeze into an existing hole,
drop it in that hole, zero everything, crank the x-axis over the
appropriate amount [determined by measuring the center-to-center on
two bolts installed in the gearbox], and lock everything down. Then
I'd run a center-cutting mill down until the witness mark appeared
on the [previously-installed] glob of layout blue on the flat next
to the hole location. That's probably over-anal but hey,
I AM on vacation. (8247) |
| Its going
to be an excellent learning project. I know drilling a hole
shouldn't be a big deal, but it has to be right, A concept that
seems largely over-looked these days. I took up home machining both
as a form of stress relief and to satisfy a desire to do quality
work. I will learn. John (8251) |
| SB 9" double
banjo (gear box change over) |
| I am still
putting together the pieces to change my 9" SB manual gear change
over to gearbox. I have the correct leadscrew coming. I've got my
gearbox lever fixed (thanks to Randy), I've receive a 20t gear
(thanks to lurch). What I need to know is where each gear goes. I
have a few Southbend books, but none tells me this. Here's the gears
that I have; (16,20 32,40,44,46,48,52,54,56,60,64,72,80, 116 on the
leadscrew, 108/13 compound gear,32 on the double gear setup, 32 on
the gear above the double gear. I also need to know what gear goes
on the input of the gear box what gear goes on the output (on the
leadscrew) Next question; Mine has a single banjo, do I need a
double banjo ? Also, from what I have listed, is there anything else
that I am missing, that I will need ? Mike
(8375) |
| 20 tooth stud gear
for most threads, 40 for a few very coarse threads, 56 tooth on the
gearbox input for all threads but one, 80-tooth idler. 42-tooth on
the gearbox input ONLY for 27tpi as in 1/8-27 pipe thread. The
leadscrew-drive gear inside the gearbox is a different face width
and I think a different bore and pitch too. With a QC box I don't
think you need the double-arm banjo unless you're using metric
conversion gears--some metric threads on a QC 9 require the use of
TWO compound gears in the train. I do know my Workshop "C" came with
a single-arm banjo and my parts book shows a double-arm banjo and
two idlers for the 10-K "B" and "C"-- certain combinations require
both arms with compound gears. Anyone got a regular 10K B/C
threading chart they care to scan and put up? The ones I put up a
while back are much older [from pre-Workshop, pre-10K Series "S"
lathes, out of a reprint of a 1942 copy of How To Run A Lathe]. Your
loose change gears are semi-surplus now...but you can certainly hit
some weird combinations with them--for example with that 116 on the
gearbox input, and the 108/13 compound on the banjo, and a 16-tooth
stud gear, and the box set to it's finest power feed of .0023/turn,
you can get power feeds all the way down to: [16/20] x [56/116] x
[13/108] x [.0023] which works out to .000106 per turn. That might
be so slow a feed the tool can't bite and just slides over the
surface...dunno. That question needs someone with more experience
than me. Myself, I can't see much use for that fine a feed except
maybe for bragging and wearing out the gearbox...speaking of which,
remember the oilers on the gearbox top only oil the bushings for
some perverse reason--they don't oil the gear teeth. For that I use
[very clingy] Harley Transmission Lube, clings good--both Harley
transmissions and SBL QC boxes are full of straight-cut spur gears.
I apply it with a turkey baster and some small tubing through the
open bottom of the box. Anyone with Excel and way too much free
time, interested in calculating all the threads and feeds possible
with a full set of change gears AND a QC box? I'd like to do it
someday but time is limited in my life. Lurch (8377) |
| 9" Conversion
"C" to "A" |
| Regarding a
proposed conversion of a C to an A Is the C apron compatible with
the A qc gearbox ? Obviously the C apron will not power cross feed
but will it feed in the normal manner (towards and away from the
chuck) ? Are any other parts necessary other than the qc box and the
appropriate length lead screw? (9088) |
| I converted my C to
an A (or B) by adding a QC gearbox. Naturally I have no cross feed
but I don't really need that. I do now have QC selected power
longitudinal feed and QC selected screw cutting capability.
Direction is changed by the reverse lever on the headstock. Some
have suggested that I'm going to wear out my half-nuts by using them
for power feed. I'll worry about when I wear them out. I have an
extra half-nut anyway so I'm covered. It was an easy change, I did
have to cut off and machine the left end of me feed screw to fit the
QC box but that was quite straight forward. I'm glad I made the
change and it was worth the cost of the used QC box. Neil (9091) |
| Re-reading your
question Robert I see that I did not answer completely. When I added
my QC box, that was all I needed. I purchased the QC box from Barry
Aronson (He advertises in Home Shop Machinist, 516-798-6330). Barry
included the 20T gear that attaches to the end of the re-machined
feed screw. My machine even had the three mounting holes in the bed
such that the QC box bolted right on after removing the Front
Bracket (holds left end of the C lead screw). South Bend sent me a
copy of the lead screw drawing (you only need the left end of the
dwg,) indicating the length to cut off and the machining necessary
to convert my C lead screw to an A lead screw. That was it. The
critical thing is to make sure you have the 20T gear for the end of
the lead screw. Neil (9092) |
| I have read
original SB literature that suggests using the half nuts to power
longitudinal feed on the C so one can (possibly, hopefully etc.)
assume it is non injurious (9093) |
| On a 'C' the half
nuts are the ONLY way to move the carriage ( other than the
handwheel ). Adding the gearbox does not change that at all.
(9095) |
| I'm in the
process of converting my "Workshop Precision," (sn42908,) to the "A"
configuration. I obtained the "A" apron hoping to simply bolt it
onto the saddle in place of the original. Unfortunately, I
discovered that the apron mounting holes on my saddle were separated
by 7 inches while those on the apron were by 8 inches. So, I had to
purchase a different saddle. Removing the head in order to drill the
3rd mounting hole for the gear box was also a problem. All attempts
to loosen the rearmost bolt securing the head resulted in spreading
my 9/16" open end wrench. The solution was to grind the box end of a
"cheapo," (K-Mart,) combination wrench until it would pass under the
bolt head. At this moment I'm waiting for delivery of a counter bore
to make the 3rd. hole. Should you need one, they are available from
"Enco" and "KBC." I'd be willing to lend mine to you, but the
shipping cost like would be prohibitive. "Enco" did not charge me
shipping. Hope this is helpful. John T. (9101) |
| 3rd Hole For
Gear Box |
| For anybody
converting to an "A" - this is how I made the third hole. First, I
took everything including the feet off the bed. A great opportunity
for a long overdue cleaning and painting. (Wish I'd done it in its
original green instead of Rustoleum grey.) I found that the 3rd hole
is 4 1/4" from the first. Next I bolted the bed, face up, with some
1/4" scrap Al between the bed and the table of my RF31. Because the
42" bed is much longer than the mill's table, I ran the table a good
distance to the right so as to balance the bed which hung well over
the left. Aligned everything and clamped the bed to the table -
rechecked alignment, it was ok. Centered the quill over the first
gear box hole then moved it over 4 1/4 inches. I'd determined the
gear box holes to be 5/16 with a 7/16 counterbore and bought a 7/16
counterbore with a 3/16 pilot from Enco. I drilled the 3/16 pilot,
then hit it with the counter bore, and finally took the 3/16 pilot
hole out to 5/16. Somehow the gear box fit like a glove and the hole
looks factory! John (9293) |
| Conversion SB9
model C to A |
In files there is a
doc about converting Model C to A in the Document there is a link
http://people.ne.mediaone.net/wasser/SBLathe it
will not work here is
there a fault in this link ? so i, am busy to convert a model C to
Model A finding a lot off troubles. the bed I have here Model C
isn't Compatible with a model A. The Series is nr 87223. imported from USA
by Landre Glinderman Amsterdam. The two feet under the bed are to
low 7 cm instead of 9 cm. the two levers off the QC Gearbox Reaching
the bench if you want to change position. i put some plywood between
the feet and the bench. The bed model C is 11,3 cm wide at the
bottom the model A 8,7 cm wide. The Gears at the backside off the
apron reaching the bed. I grinding off 10 mm off the bed at one
side. Because off wider bed the back off gearbox will not fit
correctly. the leadscrew isn't in line with the the bearing at the right
end off the bed. I have to file off a few mm off the casting off
the gearbox to. everything is working except off the Autom crossfeed
know and I a nice color Dark Green Hammerhite. The srewtreat to
hold the handle is broken. trying to drill a hole in it to cut treat
I it and attach the handle with a bolt that isn't possible it is hard
like glass. I did send some pictures to Anthony and Glen maybe
they can make a good document from this conversion better readable
the my English PS do some one know the production date off this Lathe
? Serie nr 87223 Grtz Bert
(9466) |
| I have installed an
A qc box on my postwar C without the clearance problems noted
(9469) |
| L.G.M, I just
completed conversion of my 9" Workshop Precision, ser. no. 907.
Concerning the gearbox levers, I also had to use plywood spacers
between the bottoms of the feet and the top of the table. I found no
measurable misalignment of the lead screw. Check that the lead
screw end support is not rotated 180 degrees. I believe it is
"Murphy proof," but check anyway. I was not able to use the correct
20/40 tooth gears on the rear of the gearbox due to interference of
the banjo bracket tightening screw with the gearbox housing. For the
moment I'm using a 56 tooth gear. I'm waiting on the delivery of a
double arm banjo bracket which I hope will resolve the problem and
allow me to use the correct gears. One arm of the double bracket
appears to be offset sufficiently to permit screw clearance with the
gearbox housing. I had no issues with the back gear cover. The apron
mounting holes in my saddle were 1 inch closer than those on the
model "A" apron requiring me to locate another saddle. The double
arm banjo bracket should arrive within a few days and I will advise
you whether or not is solves the clearance problem. If you have not
yet done any grinding, you might want to wait for my results. At the
moment my machine is fully operational though the screw speeds and
threads per inch do not match the chart. John
(9470) |
| Len, Maybe
that SB making later the bed smaller or that i have a special one
model C ? between gear rail and bed On the model A is a space from
about 4 mm On the model C here there is no space The gear on the
apron reaching the bed i grind the bed of a little about 1 mm to let
it turn free. Bert (9477) |
| C to A
Conversion Question |
| I
am converting my 9" Model C to a Model A...or at least trying to... I
have successfully drilled the third gear box mounting hole, and I've
attached the gear box. I've cleaned and mounted the A type apron and
crossfeed screw. The slotted lead screw is installed. I have the 56
tooth gear mounted on the gearbox shaft, an 80 tooth idler on the Y
shaped bracket. I have a beautiful 20 tooth stud gear (made by listee
Glen Reeser - GREAT work!) mounted on the headstock output shaft.
Here's the problem: The Y shaped bracket has a bulge where the mounting
bolt goes through. Approaching the position where all gears fully mesh,
this bulge fouls the gearbox casting. I did run the lathe this morning
with the 80 tooth engaging the 56 only about 70%. I can't push the
bracket on further without messing up the geometry. The powerfeeds
worked great - very smooth. But I want the gears to fully engage...It
doesn't seem right that they shouldn't align 100%. I turned the Y
bracket around, and everything lines up and runs nicely...but the slot
for the bolt head is on the gear side, and that seems flat out wrong.
Here's a picture: http://f1.pg.photos.yahoo.com/blescohier in the My
Photos folder. This is the "correct" orientation, under which the bolt
bulge fouls the gearbox (look for the red arrows) and the gears won't
line up fully. Obviously, I am either doing something wrong (likely),
or one (or more) parts are the wrong type. I am re-using the Y bracket
from the C, as I thought they were interchangeable. Bill (15128) |
| I clicked the
link and it said the album is empty I would like to see a pic before
any comment Clint (15130) |
| I ran into this
also. Despite what the parts books may or may not say, the C and A
""Y"'s are different. As I had an extra A I just used mine and did
not modify my C, however. (15137) |
| Don't have an
answer to your problem, but this ebay auction has a nice hi-res
photo of a y-bracket supposedly from a model A that might help:
2574005460 - John (15144) |
| John, and
thanks Doc and Clint too. Looks as though on a 'C' model bracket the
clamping slot lines up with the longer bracket arm, whereas on the
'A' model the slot aligns with the shorter arm. This from comparing
the picture cited by John with my bracket. They are identical
looking on page 12 of the parts list, probably to save drawing
effort....just re-use the drawing. I'll get one of the A brackets
rather than alter mine. Bill (15145) |
| Upgrading 10K
from a B to an A? |
| I have
recently acquired a quick change gear box for my old faithful B model
10K but no lead screw or extra lead screw gear. I have a couple of
questions. First, can I cut off and turn down my existing 4' B model
screw to fit the gear box to right hand support length? Second, what
gear setup do I need to get to the input side of the gear box to set
the ratios correctly? Third, what size gear do I need to put on the
lead screw?
(15399) |
| The gear that fits
on the lead screw is a 20 T gear, I believe 16 DP. On the gear box
input, it is a 56 T gear. A 80T idler gear is fitted in between the
stud gear and the 56T gear mounted on the gear box. You need a 20T
gear on the stud. To cut large threads, you need to fit a 40T gear
there. The 40T gear is usually stored as a spacer on the gear box
input. To the question about the conversion of the lead screw, it
can be done according to what I have seen on my lead screw. You will
need to manufacture a thrust collar that will need to be mounted
permanently on the lead screw. (I guess silver soldering would be
perfect. You must not put excessive heat on the lead screw in order
to avoid heat distortion Another solution is a taper pin.) Then,
some modifications will be required to the lead screw. You will
definitely need a second lathe to do this operation as threading is
required. Guy (15409) |
| So I need two 20T
gears? One for the lead screw and another for the stud? Think I will
have to start looking for a leadscrew. I forgot about that threaded
end and I am the designated neighborhood machine shop around here. (15413) |
| You need the
following gears 18 DP: 56, 40, 20 and a idler gear 80T. If I recall
the inside bore is 9/16. (with your standard change gear, you
probably have already some of them) You need a 20T 16 DP gear. The
actual measurement on mine is: 1.367 in outside diameter and 0.624
in bore. I will take a picture of the end of the lead screw for you
when I go to my car. (digital camera in the trunk) It is easy for me
to take measurements as my lathe is all in pieces. Guy (15414) |
| Converting model C to A using model C apron? |
| I have both a
model C and Model A. I was going to put both into use but have found
the half nuts and the bed a bit worn on the model A. I was thinking
of just putting the quick change on my Model C and not using the
auto cross feed. Is that ok? I don't have much use for the auto
cross feed. I will need to get a lead screw to fit, the current
model A has a 36" bed and my model C has a 42" bed. I would then
just sell the remaining parts. Space in my shop is always to small
so 1 lathe might just be better than 2. (16089) |
| If you
want the fine feed with the half nut, the model C's came with an
extra compound change gear that the model b's did not have. Now I
have no idea if that is not even a concern with the quick change
gearbox since you will not have a lateral gear feed. (16090) |
| I am looking
for a few of the gears from a Model C. 24 Tooth 36 Tooth 80 Tooth
Idler gear. Do you have any other parts from the C or A you wish to
sell? If you wish to sell these, please contact me off list.
Ray (16091) |
| SB 9" lathe
power feed upgrade |
| I have a 9" SB
lathe and would like to know if it is possible to upgrade it with
the gear box power feed. The gear change is a big hassle. Gary
(16645) |
| You can
upgrade your lathe to both QC box and power feed on the cross slide.
This is known as a 'C' to 'A' conversions. I am guessing you have a
model C. If you have a model B, then you would already have power
cross feed. Besides the QC box, you will need (to): get a or machine
your existing lead screw to a model A type. Get a 20T gear to
modify the gear train (some members might have them for sale), The
rest of the gears you should have, if you have a full set. The 'Y"
yoke or what ever it is called on the back of the lathe might have
to be modified. Drill and counter sink a hole in the bed (by the
headstock) for the extra screw the QC box needs. If you have a 'C'
and want power cross feed, you will need an 'A' or 'B' apron (same
part). Might have to modify the saddle for clearance of the gear(s)
between the crossfeed lead screw and the gear in the apron, a cross
slide lead screw (assembly) for an 'A' or 'B' lathe. I think there
might be a section in the files section about the conversion. I
haven't really priced these parts of late, but hears what I would
expect: QC box $125-200 Lead screw $50-75 Apron $75-125 20T gear (sarce
item) $20-$30 Cross slide lead screw assembly $75-$100 You might get
them cheaper or pay more if bidding on E-Bay. I would think dealers
would get at least the upper end, probably more. You could check the
Meridian website. Tom(16653) |
| Gary, I did this
modification on one of my lathes. The hardest part for me was
milling the groove in the leadscrew for the power crossfeed. I
couldn't find a leadscrew for a 4 foot lathe. I ended up making a
tool post milling head from a Taig headstock and milling the groove
on the lathe. I bought cutters to make the 20 T stud gear and I made
a dozen or so. I still have a few I'll sell for $20 postage included
in the US. Contact me off list if you want one. Glen (16656) |
| Go for it - the
conversion is a cakewalk and parts are still available. You won't
regret it. I did a "C" to "A" conversion last summer and kick myself
for not having done it sooner. Sure, it was tough spending half the
cost of my lathe on the upgrade but I'd do it again without thinking
twice. I used to dread, even fear cutting threads (I'm not a
machinist) but now, with the help of a $10.00 center gage, I cut
them with ease. John T. (16670) |
| Upgrading
model C to A |
| My concern is the
leadscrew. What is different, besides the keyway, can I shorten
original screw to fit lathe with qc box? (20057) |
| If you can mill the
keyway you will have no problem. Shortening the leadscrew, adding a
collar and threading the end should be no problem if you have
another lathe to do it on. I did it. Glen (20069) |
| Bert's C to A
conversion |
| My friend
Bert from the Netherlands is converting a C to an A and has come
across a problem that I don't quite understand. The bed on the C is
wider than on his A and there also appears to be some differences in
the shape of the casting at the bottom. This results in an
interference where the gearbox mounts and keeps the leadscrew from
lining up with the apron. I think the gearbox is laterally out of
alignment rather than too low or too high. He sent me some pictures
which I'll figure out how to post if it's necessary. Can anyone
help? Bert, Does this describe your problem? It might help us if you
could post the serial number stamped into the lathe bed at the
tailstock end on the flat near the V. Glen (20198) |
| Glen, The
serial nr,s are 87223 and the other 92866 both are SB9 models C. The
first one has a bed length off 3,5 ft and the second 3 feet. I have
the same problems twice. 1 That the clutch cover plate comes to the
bottom of the bed. I have grinded the bottom off the bed smaller
about 6 mm. 2 the gearbox will not fit without a small modification.
3 The tumbler off the gearbox come to the bench I put the lathe up
40mm under the feet that solves that problem. I sent some
pictures to Glen in the hope we could help others who's planning the
same conversion Gtz (20199) |
| More ? about
9" model C to A |
| I
also will need the cross slide screw from a model a in order to have
power feed across is this correct? I have the apron from a model A
already and I am still looking for gear box. I think I could
just make my own crossfeed screw since I have the capabilities.
(20524) |
| Your
cross slide screw needs to look like the one in this listing. (dead
link) The spline gear engages the worm gear in the apron. The large
dial and ball thrust bearings are nice but not necessary. The third
photo shows the critical part. When I did my conversion the cross slide
screw was from an "A" or "B" even though the lathe was a "C". Check out
what you have before you buy a different one. Glen (20528) |
| Yes you need a
different crossfeed screw, the A or B model screw has splines for
the power crossfeed (20539) |
| 9" Lead screw
question (converting c to a) |
| I am converting a c
to a model a I need to cut the lead screw from my c to fit the a I
need to know what size the keyway along the lead screw is. (20723) |
| BOB WRIGHT responded: Mine is .187
wide and .100 deep. This may turn out to be 1/8" deep. The problem
is that, when measuring the depth starting from the side of the
screw adjacent to the keyway, your base point is lower than the
original uncut surface. To illustrate, draw a circle, draw a keyway
cut into the circle, join the top edges of the keyway, you will see
that there is an arc extending outside the cut surface which
represents the original diameter of the leadscrew *without a
keyway*. The way to measure this correctly to get the depth of cut
for the keyway is to measure the diameter of the leadscrew across a
section without the keyway, then measure from the bottom of the
keyway to the far side of the leadscrew, then subtract the second
value from the uncut diameter. This will give a value for how deep
to cut from the uncut circumference. Bob, which method did you use?
Anthony (20735) |
| Anthony, I measured
the cut keyway across the cut to the bottom on the first post. Then
I thought about it. Deleted the first post and reposted a second
response, I measured the far left side from the top of the uncut rod
to the bottom of the slot. Bob
(20736) |
| Contemplating
a conversion from 9C to 9A |
| I have two
lathes. the 9A is well used, ugly and worn. I would like to put the
QC leadscrew on the Workshop (9C) and the saddle. I know it will be
some work to clean up the saddle, but it seems like the fastest and
simplest way to get one better lathe. Has anyone done this and if so
do you have recommendations on the best approach ? Selling the two
and buying a third is an option. Dave (24218) |
| There used to be
stuff in the files section on this conversion. It is now empty. I
checked the sister group and did not find it. Perhaps Denis can
help? Jim B.(24222) |
| The file is now in
the southbendpixgroup. Depending on the vintage of your 9C, there is
considerably more than is stated in this file if it is early. The
early model does upgrade well, as I have done on my '37. Harve
(24224) |
