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View Full Version : Removing the backgear from the headstock of a 9" Southbend Model C lathe???



atomicjoe23
09-16-2011, 12:18 AM
I would like to remove the backgear and shaft from the headstock of the 9" Southbend Model C Workshop lathe that I recently aquired so that I can clean everything up and get this thing back up and running. . .

. . .only problem is I can't seem to figure out how it's supposed to come out.

The restoration manual that came with the lathe (a pretty decent one at that. . .at least it has been up until this point, but there seem to be a lot of variations in manufacture over the years for lathes) says that there should be a taper pin in the back gear lever and in the eccentric bushing, but I don't see any. . .

. . .was there a variation that didn't use taper pins to retain these items?

I just don't want to break anything on this thing trying to get it apart for cleaning. . .I could just clean it with the back gear in place, but I'd like to do a little more thourough job than that.

Thanks for the help!

RussZHC
09-16-2011, 02:48 AM
Don't own a South Bend and I am not being sarcastic BUT...take another careful look (if it seems to indicate that is what they are supposed to have)...those taper pins, esp ones on older machinery, can be very, very tough to spot and if you find it and its in a difficult to reach/see place, look again to be sure which end is actually smaller...sometimes it takes a swipe or two with some sandpaper and then a greasy finger smear to reveal where the edges of those pins are...

flathead4
09-16-2011, 07:25 AM
Here is a picture of the backgear on my Model A which should be the same as your Model C. You have to remove the taper pin from the eccentric bushing to remove the backgear. It may be hard to find the pin if it was ground flush. I would not remove the taper pin from the lever unless it is damaged and you need to replace the lever. My machine is fairly new (1966) and I don't know if earlier Model A,B,C's were different. I do know that the Model 405 (1934) did not have a taper pin. The shaft was held in by a split bushing. You had to loosen the bolt in the head stock and tap the shaft out.

Tom

http://home.comcast.net/~boergertt/sb9a/sb9a-5.jpg

jclem40c
09-16-2011, 09:09 AM
my moneys on the taper pin. look again closer you'll find it.
I got 3 South Bend 9s and they all have taper pins

John

atomicjoe23
09-16-2011, 09:22 AM
I will look again for the taper pin, but the Model 405 with the split bushing makes me begine to think. . .

. . .the serial number (52691) on the lathe bed indicates a 1933 as the year of manufacture (according to the SN listing on wswells.com), but the banjo lever looks like a 405 banjo lever not a 9" banjo lever, also there are definitely split bushings on both ends of the back gear shaft housing and there were bolts which I already removed. This is why I was asking. . .

. . .it is entirely possible that I either have an early 405 or I just have some mismatched parts (i.e. a 405 headstock and a 9" bed).

Does anyone have a pic of the 405 headstock housing around the backgear so I can compare mine???

flathead4
09-16-2011, 09:54 AM
Here is a picture of a 405 I used to own. Notice the split bushing. I might have a pictuer taken from the back. Also notice that the 405 headstock has the spindle oilers on top.

The serial number on my 405 was 55927. Sounds like you have a 405.

Tom

http://home.comcast.net/~boergertt/sb405/405-2.jpg

atomicjoe23
09-16-2011, 12:28 PM
That is exactly what my headstock looks like. . .same split bushings and top oilers. . .

. . .someone on another forum suggested that I might have a Toolmaker lathe. . .thoughts on this.

Where can I get more info on the 405 and how much of the parts are interchangeable with the 9"? Seems like quite a few from what I have already purchased for this lathe (parts for the apron mainly).

flathead4
09-16-2011, 02:42 PM
I don't believe the apron or saddle will exchange between a 9C and a 405. For one thing the leadscrew on the 405 has left-hand threads. If your 405 is pretty much complete and in fair shape, I would just use it. That's what I did. I did strip mine to bare metal and repainted it but made few other changes. I have read accounts where people have replaced the headstock with one from a Model C. The bed on the two is pretty much the same so that will work. In my opinion, the 405 is about as good as the Model C. I think the compound is a little beefier on the C. The other issue with the 405 is that the spindle has a 1-3/8 X 10 thread instead of the more standard 1-1/2 X 8. This makes it difficult to find chucks, etc. that will screw onto the 405 spindle. The solution of course, since you have a lathe, is to make your own. Below is a picture of my 405 after the repaint.

Tom

http://home.comcast.net/~boergertt/sb405/405-20.jpg

atomicjoe23
09-16-2011, 04:30 PM
That looks like what I have. . .

atomicjoe23
09-16-2011, 05:02 PM
I'll post pic's up tonight. . .in it's dis-assembled state that is, I still have to repaint and re-assemble it.

atomicjoe23
09-17-2011, 01:10 AM
Pic's are in this thread. . .

http://bbs.homeshopmachinist.net/showthread.php?t=49945

So, if I have the split bushings it is safe to tap the back gear out after the bolts are loosened/removed.

My lathe has a 1.5" x 8 TPI thread spindle nose, the bed is 6" wide (I read different lathes had different way widths), a single arm banjo lever, and a RH thread lead screw, but the headstock and apron look just like the above 405. . .the serial number indicates a 1933 model.

flathead4
09-17-2011, 09:38 AM
That does not look like 405 to me. It looks more like a 415 which I believe overlapped the 405 production. It's possible you have a 405 bed but the rest I'm pretty sure is 415. The 405 headstock does not have the reovable bearing caps, has a longer banjo, doesn't have a reversing lever (uses a seperate stud gear) and the apron is completely different. Hae you tried the South Bend Lathe forum at practicalmachinist.com or the South Bend Yahoo group? Both forums have folks knowledgable in these lathes, too.

Tom

atomicjoe23
09-17-2011, 09:56 AM
That does not look like 405 to me. It looks more like a 415 which I believe overlapped the 405 production. It's possible you have a 405 bed but the rest I'm pretty sure is 415. The 405 headstock does not have the reovable bearing caps, has a longer banjo, doesn't have a reversing lever (uses a seperate stud gear) and the apron is completely different. Hae you tried the South Bend Lathe forum at practicalmachinist.com or the South Bend Yahoo group? Both forums have folks knowledgable in these lathes, too.

Tom

Aaaaaagggghhh. . .and another model possibility, that makes 4 different models this thing has been suggested to be! Sold to me as a 9" Workshop Model C, suggested to be a 405, 415, or Toolmaker lathe.

I have posted on practicalmachinist.com, but I haven't been on the SB Yahoo group. . .I'll try there as well. . .I'm beginning to think I have a hybrid (and if I didn't before, well, I do now, because I have bought one or two parts that were "missing" that are 9C parts (spindle thrust bearing, as well as the headstock and tailstock mounting clamp feet, but they all seem to fit just fine). I'm gonna give SB a call on Monday and see if they can tell me what the serial number on the bed (52691) goes to. . .but that doesn't help with the headstock or apron areas. . .

. . .does the 415 have LH threads like the 405? My lead screw has RH threads, the spindle nose threads are 1.5" x 8 TPI.

Time to go do some more research I guess.

atomicjoe23
09-17-2011, 10:14 AM
I just got of wswells.com and I was looking at the 1933 Toolmaker lathe catalog and it looks very similar to that. . .a 9" lathe with backgear, the half-nut lever looks the same (which has been one of the parts that haven't matched the 9C or the 405 so far), it has top oil gits and split spindle bushing housings, has a 1.5" x 8 TPI threaded spindle nose, the cross-slide dial is graduated, and the compound is graduated (not on the dial, the angular adjustment). . .all of which are listed as charachteristics of the Toolmaker lathe in the catalog. Some of the model numbers are very similar to mine. . .the catalog # that is on the brass plaque on one of the gear covers that came with my lathe is 420-ZB. There is a 20-ZB and a 420-Z, but I didn't see a 420-ZB on there.

Two gears (I'm not sure if they are change gears or not yet) came with the lathe one is stamped 81T and the other 92. . .I will post pictures after my camera is done charging.

atomicjoe23
09-17-2011, 10:17 AM
Just had a potential epiphany. . .so Catalog # 420-Z is for the 9" #20 Toolmaker lathe with the 3 1/2' bed without the bench, could the additional "B" in my catalog number mean that mine was one sold with a bench originally???

I have the 3 1/2' bed as well. . .

The threading label plate looks identical to the one in the illustration for the Toolmaker lathe as well, but I'm guessing most of the threading plates were used on all the lathes they applied to and were not unique to each individual model.

atomicjoe23
09-17-2011, 11:39 AM
Got the back gear shaft removed. . .once I figured out that I had split bushings and I knew there weren't taper pins it tapped right out.

Thanks for the help. . .and I'm pretty darn sure I have a 1933 Toolmaker lathe now.

atomicjoe23
09-18-2011, 07:29 PM
Here are the pic's of the gears. . .maybe you guys can tell me if they are change gears or not. . .

92 tooth gear
http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/313426_289599814390192_100000205277807_1381221_144 9161612_n.jpg

81 tooth gear. . .has 8-36J stamped on one side of it. . .
http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/318775_289599741056866_100000205277807_1381219_200 4238790_n.jpg

atomicjoe23
09-18-2011, 07:34 PM
Both gears are 3/8" thick with a 5/8" bore. . .

. . .the 92 tooth gear is 0.377" thick with a 0.625" keyed bore while the 81 tooth gear is 0.367" thick with a 0.625" smooth bore with a reducing bushing in it taking the bore down to 7/16". . .don't know why though???