New to me South Bend 9"

I just purchased a South Bend 9" and from what I have learned on line it could be a Model C.
The longitudinal feed is powered but the cross feed is not.
The jack shaft is not adjustable with a break over center device to set the flat belt tension.
The motor appears to be a 1/4 horse and seems to be on the weak side.
The lathe came with 10 extra gears which I assume are screw gears to change the speed of the tool apron.

I have several questions about this lathe that I am sure this forum can help me with.

1. I want to make the jack shaft adjustable with a quick adjust break over mechanism to set the flat belt tension.
I could bolt the existing jack shaft stand and motor onto a hinged plate and fabricate an adjustable turnbuckle break over device.
The only place I can see on the lathe to attach the turnbuckle device is using the bolts that hold the the spindle bearing caps.

2. What horse power motor should I consider using, to upgrade the current possibly tired or underpowered motor?

3. The lathe came with one idler gear that has both a large and small diameter gear as a single piece.
The stud gear drives the large diameter gear and the small diameter gear drives a large diameter screw gear.
I would like to speed up the feed speed but none of the extra gears are big enough in diameter to reach and mesh with the the small gear on the 2 gear idler gear.
Under the nut on the feed screw is first the large diameter screw gear and then an approx. 5/8 th's thick bushing.
If I reverse the bushing and the screw gear on the feed screw, this would allow the screw gear to fit further onto the feed screw and be inline with the big gear on the idler gear.
Then I could by pass the small gear on the idler gear which would allow me to use the extra gears that came with the lathe and will definitely speed up the feed speed.
I am concerned that this will end up with too fast of a feed speed even with the largest diameter screw gear.
The problem is that the extra gears appear to have an interference fit on the feed screw and would need to be driven further onto the feed screw which leads me to believe this is not where they were intended to go.
From photos online it appears these lathes are used with 2 idler gears where as mine came with only one and that may be the problem.
So my hope is that someone can enlighten me on how to use these extra gears to slightly speed up the feed speed or am I missing an idler gear to make this happen?
I am not interested in turning threads at this point.

4. I found a South Bend phone number and called hoping to get some answers.
Turns out they do not offer technical advice and can only sell you parts if you have a part number.

5. Where do I source a hand wheel for the tailstock?

I will appreciate you consideration on helping me understand the use of this lathe and where parts are available.

Thanks
Herman Pahls
Coquille, Oregon

Hi Herman, i don't have any advice on your belt drive, but I know that hand wheels show up on ebay all the time. As to the change gears, I found that, the South Bend book 'How to run a Lathe' was invaluable. It has gear charts for all the different speeds, and how to arrange them.
Also looking at my model C which is a 1938, it has a mount for the pivot assembly cast into the headstock. maybe a pic of your lathe would help.
Additionally, a 1/2 horse power motor is usual to these, I run a 1/3 horse on mine.

It sounds like you have the non-adjustable horizontal (bench mount) motor drive, in which case, your headstock wouldn't have a place to attach the tensioner rod. The internet abounds with pictures of the adjustable countershaft configuration.

Change gears varied over the years, but my 1938 9c utilizes three idlers; two compound, which include a 54/18 and a 72/18, and an 80 tooth.

Paul

You need this or a better copy

http://campkahler.com/files/How_to_Run_a_Lathe_SB_1of2.pdf
http://campkahler.com/files/How_to_Run_a_Lathe_SB_2of2.pdf

a 1/2 HP or a 1/3 HP motor will work much better on your 9 inch lathe. a 1/4 HP like you said is weak..

If you want to change the feed speed, you don't flip over the compound gear. Instead, you remove the spacer from under the leadscrew gear, and put it on the outside instead. However, I think you will find that any feeding you do without the compound gear in use will be too fast. You should have an 80 tooth gear which will reach to the small gear on the compound.

allan

Here's what that 80 tooth idler looks like: Excellent Original South Bend 9" 10K Lathe 80 Tooth 80T Idler Gear Part 33N1 | eBay

If you watch and wait, you can probably get one a lot cheaper.

1/4 on a 9" might be a tad light, but doable. Old motors have more uumph than new ones of the same ratings. I have a 1/4 HP motor on an small 6" bench lathe, much more power it needs.

Thanks to all those that responded to my questions.
1. I have come to the conclusion that my only compound gear is larger in diameter than what most South Bend owners have.
Paulmo said he has 54/18 and 72/18 compound gears.
My only compound gear is around 100 teeth and that is why the only gear that reaches the small gear is a 102 tooth screw gear.
Kitmo 455 said a 80 tooth screw gear should reach and in my case it doe not come close.
If I had a 72/18 compound than the 80 tooth might reach.

2. I have found as Kitno 455 said that without using a compound gear the feed speed will be too fast.
This lathe came with 12 extra change gears (18 thru 80 teeth count, all have keyways) so I am trying to figure out where and when I would use them since none of them will reach the small gear of the compound gear I currently have.
It appears that I need to get a 72/18 compound so at least the 80 tooth screw gear will reach, which will speed up the feed speed but that leaves 11 gears.
If I get a 54/18 compound gear than more of the screw gears will reach but the feed speed will probably be too fast.
So I assume the faster feed speeds are for cutting threads.

3. Do the keyed gears only get used on the lead screw even though they will fit on the idler gear bushing?

4. The stud gear on this lathe is very small in diameter and I am guessing only 12-14 teeth.
The stud gear has I believe 9/16" I.D. and all the others are 5/8" I.D. so it appears the extra gears were not intended to be used as stud gears.

Any further advice regarding what compound gears I should purchase and when I would use the stack of 12 extra gears would be appreciated.
Thanks again
Herman

We need a picture of this lathe, and the end gearing, and tell us the serial number off the upper right end of the bed. The 9" workshop gears fit the stud and the leadscrew, but should not fit on the idler bushing, it is too big. I think you might have a different lathe than we think...

allan

agreed.
if you can`t do pics, some fishing around on this site might help,or go to the links section here and check out the "SBLworkshop" website.

Page Title (this is just one page of many to look at there)

as a shot in the dark-the 5/8" bore gears make me think of a 405??, does it look like this?
http://www.wswells.com/photos/1934_405_tom_boergertt/slides/405-13.html

I would like to post photos if someone would tell me how from an I Phone.
I will also get serial # now that I know where to look.
Thanks
Herman

herman pahls said:

I would like to post photos if someone would tell me how from an I Phone.
I will also get serial # now that I know where to look.
Thanks
Herman

Click to expand...

Take the photo, go to your camera roll (sunflower icon), view the photo, then there is a box with an arrow icon in the lower navigation bar. Click that and hit "email photo'' Then email it to yourself. Then check your email on your PC, download them and upload to the advanced reply form.

Or you can plug it in to your computer and download the photos directly, just like a camera.

If you use the cloud, sign in to your iTunes account and view/download them from your PC. (no cords)

Many ways to do it.

Does your lathe look like this one:

Page Title

allan

Sounds like to post photos, it is best that they get transferred to a PC.
I was hoping there was an easy way to post photos directly from an I Phone.

The photos that kitno455 posted will save me having to try posting my own since that is the same basic lathe with some minor differences.

1. That lathe has a break over flat belt tensioning device whereas my jack shaft stand needs to be adjusted with elongated holes and then the motor needs to be adjusted also since they are both mounted to the table separately. I would like to find the jack shaft mechanism as pictured instead of building my own.

2. The only other differences besides the on/off switch is the gear set up that drives the feed screw.
My lathe came with a stud gear reversing mechanism.
The pictured lathe has 2 compound gears that drive directly off the spindle gear.
My lathe came with only one compound gear and and it looks identical in size as the larger one pictured.
My biggest diameter screw gear also appears to be identical (approx. 100 teeth).
The difference is that my one compound gear is reversed (the little gear faces the left side of the lathe) , so the my screw gear is first under the nut on the feed screw and then the spacer bushing.
If I had a similar 2nd compound gear I would need to set up the gears as pictured to get them to line up with my stud gear which is only one gear in width versus the wide spindle gear as pictured.

I appreciate these photos since it helps explain why with my current set up the additional keyed screw gears will not reach the small gear on the compound gear since the largest is 80 teeth.

I hope that my explanation makes it clear as to what I currently have and help you advise me as to what parts I need to order to make the lathe more versatile.
Thanks again
Herman

Interesting- most 9C workshop machines (with the reverse tumbler) came with the 54/18 and 72/18 compound gears. The older 9 Jr came with 81/18. Sounds like you have the 108/18 which came with the intervening Model 5. You need a slightly smaller compound, or a slightly larger leadscrew gear.

First, we need to verify the DP of your gears. Take one of your larger gears, and measure the outer diameter in inches and count the teeth. Then: ( Teeth + 2 ) / diameter = DP. This should be close to an even number, most likely 18, but possibly 20. Also measure the bore (likely 9/16) and the thickness (face width) (likely 3/8)

allan

Hello Kitno455
I have gathered the lathe info you said would be helpful.
The name and data plates are so warn that I needed to magnify to attempt to read them.
The swing is 9" and the bed is 3-1/2
The Catalog no. was not clearly visible but appears to be 420-Y and the Y was not a for sure.
The stud gear is 16 teeth which is part of the reversing device.
My only compound gear is an 81/18 which you said the older 9 Jr came with.
The only screw gear that will reach the 18 tooth gear on the compound gear has 92 teeth.
The 92 tooth gear is 5.223" in diameter. So (92+2)/5.223 = 17.98 = DP

Are screw gears and change gears the same?

The 81/18 compound gear is 5/8's I.D.
The 92 tooth screw gear and the spares (80, 72, 64, 60, 56, 52, 48, 46, 42, 40, 32 teeth) all have 5/8's ID and key ways plus they have 8-32 stamped on most of them.
The gears measured .393" wide so essentially 3/8's.

I hope this information will help you advise me what I have and what gears or parts I will need to make the lathe more versatile.
Are there times I should remove the reversing gears and drive the compound and screw gear off the main shaft gear as I have seen pictured?

Thanks again
Herman

Here are some captured shots from the second link I posted in post #4 that may be of some use.

One shows the set up with double compounds. Another is the B and C gear charts, also showing double compounds, at least in the right hand C chart.

With out double compounds your finest feed rate will be .0048 IPR

The 420 is shown in the 1934 catalog 94

herman pahls said:

Hello Kitno455
I have gathered the lathe info you said would be helpful.
The name and data plates are so warn that I needed to magnify to attempt to read them.
The swing is 9" and the bed is 3-1/2
The Catalog no. was not clearly visible but appears to be 420-Y and the Y was not a for sure.
The stud gear is 16 teeth which is part of the reversing device.
My only compound gear is an 81/18 which you said the older 9 Jr came with.
The only screw gear that will reach the 18 tooth gear on the compound gear has 92 teeth.
The 92 tooth gear is 5.223" in diameter. So (92+2)/5.223 = 17.98 = DP

Are screw gears and change gears the same?

The 81/18 compound gear is 5/8's I.D.
The 92 tooth screw gear and the spares (80, 72, 64, 60, 56, 52, 48, 46, 42, 40, 32 teeth) all have 5/8's ID and key ways plus they have 8-32 stamped on most of them.
The gears measured .393" wide so essentially 3/8's.

I hope this information will help you advise me what I have and what gears or parts I will need to make the lathe more versatile.
Are there times I should remove the reversing gears and drive the compound and screw gear off the main shaft gear as I have seen pictured?

Thanks again
Herman

Click to expand...

herman pahls said:

Hello Kitno455
I have gathered the lathe info you said would be helpful.
The name and data plates are so warn that I needed to magnify to attempt to read them.
The swing is 9" and the bed is 3-1/2
The Catalog no. was not clearly visible but appears to be 420-Y and the Y was not a for sure.
The stud gear is 16 teeth which is part of the reversing device.
My only compound gear is an 81/18 which you said the older 9 Jr came with.
The only screw gear that will reach the 18 tooth gear on the compound gear has 92 teeth.
The 92 tooth gear is 5.223" in diameter. So (92+2)/5.223 = 17.98 = DP

Are screw gears and change gears the same?

The 81/18 compound gear is 5/8's I.D.
The 92 tooth screw gear and the spares (80, 72, 64, 60, 56, 52, 48, 46, 42, 40, 32 teeth) all have 5/8's ID and key ways plus they have 8-32 stamped on most of them.
The gears measured .393" wide so essentially 3/8's.

I hope this information will help you advise me what I have and what gears or parts I will need to make the lathe more versatile.
Are there times I should remove the reversing gears and drive the compound and screw gear off the main shaft gear as I have seen pictured?

Thanks again
Herman

Click to expand...

Oh my. I'm glad we asked. That is a Toolmaker 20. This lathe is the first of the narrow bed 9" southbend lathes. You can think of it as the grandfather of the now ubiquitous 9" Workshop. This lathe was only made in 1934 or so. Here is a catalog: 1933_Circular_No.9-G The 16 tooth stud gear should come off. If you measure it's shaft, and that of the leadscrew, you might find that they are not the same size...

allan