1931 Lathe HELP

Hello all,
I am newer to machiening and decided to get/learn turning. I couldn't pass up the opportuinty to purchase a lathe for scrap pricing. I purchased a sad 13 by 6 South Bend. Following is the informaton given to me by SB.
1. Serial Number: 50323
2. Catalog Number: 166-C
3. 13-1/4"X6'
4. Ship Date: October 7, 1931
5. Original Customer: A. O. Smith Corporation in Milwaukee, WI.
I have no other info, So i basically have some questions and need of help locating parts and parts suppliers. I am at witts ends trying to figure out what is supposed to be where and what i dont even have.
On the revering assy there is the spur gear. The one that came with the machine is a 32T about 2 3/4 dia. I have a single tumbler QC GB. I need to repair or replace this gear being it is missing 3 teeth, IS this the proper gear? Where can i get one(someone beat this in and bent teeth also)?
I have installed the gear and setup the gb for 12 tpi and rotated the spindle 12 times and the carrage does travel an inch.
2. Attached is a pic of the left side of the headstock. I have 2 holes on top of the spindle bushings. Are these for oilers? Where do i get these?
On the last gear to drive the QC GB there is a hole on top of the mouting braket(a screw is on the bottom); What is this for, a oiler or a screw?
my motor mounting plate is a fadricated 1/4 inch plate not setup for tension adjustment. I was going to drill a hole to let the bolt pass through but does anyone have a original theyd sell? and know how to change it. A previous owner allredy cut a hole on either side of the shaft that mounts it. They also lost the left and right cover for the leg.
What kind of lubricants should i use?
I apoligise , this is alot but my searches so far have not been too helpfull. I really want to get this back up and running. I refused to run ith with a motor with a bent shaft and bouncing all over the place.
Thanks
FortyTwo

The 2 pics

Attached


IMAGE(http://factorydaily.com/fdattachs/fdattachs3/112114114566574.jpg)


IMAGE(http://factorydaily.com/fdattachs/fdattachs3/112114114666577.jpg)

Correction the spur gear is a 36 tooth.

166-C is a Series N (!)
If you look on Steve Wells web site, he has a scan of Bulletin No. 100 from April 14, 1931, that has info about your lathe
John

I've done the same as you, only a bit smaller machine - 11 x 4'. The gear train looks the same. I'm in the process of making new back gears for it, and the half-nuts will be next. Your photo is kinda small; blurry when enlarged. I'm not clear on which of your gears is broken, but it's probably the proper gear.
Use 20 wt turbine oil - something for machinery. The paraffin based automotive oils will plug it up. Try an air compressor dealer for oil.

Thank you for the infor so far.
Johnoder - that bulliton helps alot, i now know how the machine is supposed to operqate, spindle thread, and other specs. From what i can tell from my experiment and rough parts diag on s wells site the 36 tooth gear must be right. The later 13 inch lathes must have all used a smaller gear but this one used a bigger one.
lodsb- i apoligise the gear is actually on the table in front iof me and not in the pic. It is the spur gear on the lower part of the reversing assy. Approximat;e 5/8ths thick 36 teeth and just less than 2 3/4 in diameter. I got a lube specs from south bend but i would like to find lubricants locally i can use. I will check out compressor shops.
2 big questions i have left.
Where / how can i get a replacement gear and or get this one repaired.
On the top of the banjo bracket that is between the QC gearbix and the drive gear in the pic there is a hole in the bracket. Is this for a oiler or a bolt. McMaster carr has the oilers i need for the headstock BTW.
Thanks for the info
ForytTwo

You could always just make a new gear for this machine:
Seneca Falls gears...
Before:
IMAGE(http://www.metalworking.com/dropbox/SF_gear01.jpg)
During:
IMAGE(http://www.metalworking.com/dropbox/SF_gear15.jpg)
After:
IMAGE(http://www.metalworking.com/dropbox/SF_gear16.jpg)
This was for a seneca falls machine.
Jim

Where to buy a new gear for a 75 year old machine.. I'm not positive, but I think they used a stub form - the usual $50 cutter isn't right. Someone please correct me on this. You could do as Jim has shown in his "before" picture, drill and tap for small studs, then file to shape. Or glop on some braze, filing to shape. I used a CAD program and some math to design a single point cutter but it goes real slow, taking about 30 minutes per tooth with my current setup on the larger back gears. I need to go back to the drawing board, but I replaced all the teeth with a ring of steel - heat shrunk to fit the old hub. I used the single point method on a smaller gear for my Logan QC and got it done in an afternoon. 40 teeth, 2" dia, 3/8 thick.
The real method involves hobbing. Maybe someone here will point the way to getting one bought/made.

THat seneca falls lathe was definitely over 75 years
old and it used standard pressure angle tooth forms.
This was confirmed with a trip to a profile projector
which is one of the better ways to check this.
And yes the cutter was pretty inexpensive.
BTW the repair was done by a former owner, not me. I'm not
entirely sure I could have done such a nice job, which
is one reason I wanted to save the original, repaired
gear rather than mill the repairs out, silver solder in
some steel biscuits, and re-cut only those teeth.
Plus, I wanted to try my hand at cutting spur gears.
Jim

You can also have a wire EDM cut the gear. All the dimensions are available in machinery's handbook, or can be calculated with software. Make a blank, take to a machine shop with EDM. They will create a model and write a tool path. The EDM can cut very accurately, no need to worry about gear hobs, etc., cost should be about the same. You can also take a class at the jr college and use ProE or Solidworks to make your own model to give the machine shop if you want ot reduce costs.
Of course, you can also cut your own gear at home using methods shown right here on this BB.

Wire EDM was my second choice if I could not figure out
how to do it with a form cutter. But that would have
involved begging, wheedling, whining, and bribing the
wire guy at work....
I try not to ask for favors very often.
Jim

Just a thought, I'd look at Boston Gear in the MSC catalogue, or buy a stick of 36t "stuff" from Green Bay Mfg. and bore it. You'll need to know the pressure angle, I'd bet it's 14 1/2 degrees. There's charts/calculations on the boston gear web page that will help you figure it out, along with Jim Rozen's method.
Yes, I've made gears. 27t gears are hard to find. A 36t is not. If I can buy a ready-made (or close), it saves me time to fix other things, or, heaven forbid, actually make something besides parts for my machines.
I just bought 5/8" x 10 bronze Acme sleeve nut from Green Bay, 24.10 plus shipping, REALLY nice folks, 20 buck minimum order. Alternatively, I could have bought some bronze and a duplex tap - prob. more than 24 bux, or some bronze, an acme thread guage, etc. and tried my hand at cutting internal acme threads.
With the purchased part, I can repair the X feed on my mill in less than a day for less money.
But that's just me.

Hello all,
I have installed the gear and setup the gb for 12 tpi and rotated the spindle 12 times and the carrage does travel an inch.
FortyTwo

From this I understand that the carrage moved less than 1".
I would guess that you might have the horizontal feed engaged and not the half nuts.
The cluch should be disengaged, the selector lever in the middle and the half nut lever up.
Also there is always a fair amount of play in the system so give the spindle a few turns befor starting to count.
Jim B.

WOW! alot of ideas.
I have not contacted green bay gear or boston yet. mainly because Ii have no idea of the tooth specifics. I am kinda new to machineing so i dont want to tackle machineing it myself- yet. I was going to take a hobbiest class at the local tech in the fall semester but dont relly want to wait all summer for the parts. They do have cnc's ?
or if i knew what the specs on the teeth were i could buy a gear tooth cutter. On ebay there are some all the time. I would need to make a cutter holder and prolly get a driver plate, a set of dead centers, and the special 1 inch headstock to morse taper 3 adapter that was supposed to come with the lathe.
What about welding in the teeth and then machining the teeth out? this would be a smaller task than making a new gear?

From this I understand that the carrage moved less than 1".
I would guess that you might have the horizontal feed engaged and not the half nuts.
The cluch should be disengaged, the selector lever in the middle and the half nut lever up.
Also there is always a fair amount of play in the system so give the spindle a few turns befor starting to count.
Jim B.

Jim i do apoligise for my poor writing style. The carrige DID move an inch, verifying that the 36 tooth gear is correct. I did it with the half nuts engaged and i think the selector plunger out. (no lever on this baby) I figured if it was supposed to be a 18 tooth it would have moved twice as far (approximately).
FortyTwo

36 teeth and just less than 2 3/4 in diameter

Sounds like 14DP
It will for a fact be full depth (not stub) tooth form and 14 1/2° pressure angle
The reason for different gears later was the single tumbler QC changed from a max of 2 TPI to a max of 4 TPI.
John

Should be: The cutters I have that ARE 20° PA say so, while those that are 14 1/2° PA DO NOT say anything about pressure angle.
John

"I wuz blind and could not see, and now I can shoot my mouth off!"
Does not look like either Boston or Green Bay have anything that will work.

Yea i found out the some thing today, i checked out the boston catolog and found nothing for the tooth and depth needed. The clerk at imotion ind was quite rude about it claiming i was wrong because it was not in the book.
I have a local machine shop checking into getting a blank for me but i fear the price. I have had them do work for me before and they are quite resonable, and extremely skilled.
I just got my drum switch wired and installed today, and got the motor assy all put together. All i have to do to turn it on is run the wiring to the outlet and then i am off the oils and belts.
I did not purchase the cutter because i relize i need a mill, a indexing head and some skills, a bit above my current level.
thanks
FortyTwo
P.S. maby i might even work on my other project from south bend indiana, my studebaker this summer!

THat seneca falls lathe was definitely over 75 years
old and it used standard pressure angle tooth forms.
This was confirmed with a trip to a profile projector
which is one of the better ways to check this.
And yes the cutter was pretty inexpensive.
BTW the repair was done by a former owner, not me. I'm not
entirely sure I could have done such a nice job, which
is one reason I wanted to save the original, repaired
gear rather than mill the repairs out, silver solder in
some steel biscuits, and re-cut only those teeth.
Plus, I wanted to try my hand at cutting spur gears.
Jim

Jim,
I checked out the thred you had n making your gear and WOW nice work. I would have thrown something if i would have missed on the last tooth. But the final product looks real nice.
FortyTwo

Add new comment

Images
More information
  • Files must be less than 2 MB.
  • Allowed file types: png gif jpg jpeg.
Documents
More information
  • Files must be less than 2 MB.
  • Allowed file types: zip rar.