My new 1943 South Bend 9c lathe

Ryan313 said:
I was hoping you were a teacher honestly, although that is still very interesting. I went to vocational school for welding, and I reference the textbooks occasionally. I was hoping that you could recommend some machining textbooks.
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I'll look around and see what I can find to recommend, I think most of the old Army and Navy texts are free online, and after spending 16 years in the Army, I can tell you they assume you know NOTHING!

You might think about drilling and tapping a hole for a belt clip from a cheap tape measure. On the facing, it looks like chatter. You may need to adjust the gibs on the cross slide and compound. Or possibly play around with how fast you feed it across. Too slow can be as bad as too fast!
 
SupplySergeant said:
I'll look around and see what I can find to recommend, I think most of the old Army and Navy texts are free online, and after spending 16 years in the Army, I can tell you they assume you know NOTHING!

You might think about drilling and tapping a hole for a belt clip from a cheap tape measure. On the facing, it looks like chatter. You may need to adjust the gibs on the cross slide and compound.
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I like that idea! The issue is that working on a barge, dropping a tool often means it is lost to the river. Sometimes you can get lucky with a magnet, but it’s better to have things mounted as securely as possible without it being a hassle.
 
Thanks for the reference, I will check it out.

I adjusted the gib screws according to THIS book I ordered when I first got the lathe. The book says to tighten the screw until drag is felt, and back off 1/12 turn, or maybe it was 1/8 turn. I do not recall as I did this several weeks ago. I will try different feed speeds. I will also post some pictures of the tool bits I ground, maybe that is my issue.
 
The part I made for my wrench is a bit short to fit on a belt; when I made it I did not measure, I just started making chips. In an effort to get better results I thought a boring bar would leave a better finish than a drill on the inside. You can see the set screw is too long, but that’s what I had at the moment. I am not very happy with the finish that I got, but I suppose it would work. Just as well either way.
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I used a broken drill for the tool bit, and it worked decent. I tried it out on the first wrench holder, and saw something I could not see before. I am not sure if it is because the bit is pushed the other way, but the cross slide is moving all over. Part of the movement seems to be backlash, so I held the dial the best I could, to see if it stopped. Holding it in place seems to help, but I can still see a bit of movement. I would guess it is coming from the T shaped nut on the underside flexing. The cross slide does not appear to have a lock, which I think would fix that problem. I think I really need to start taking it apart and see the condition of the parts before I try to make anything else.
 
There may be heavy wear in the part of the crosslide that got the most use. This can make it difficult to adjust the gibs, since they'll be too tight at the ends of the travel, and too loose in the middle. You wind up either rescraping the ways, or finding a middle ground you can live with.
 
SupplySergeant said:
There may be heavy wear in the part of the crosslide that got the most use. This can make it difficult to adjust the gibs, since they'll be too tight at the ends of the travel, and too loose in the middle. You wind up either rescraping the ways, or finding a middle ground you can live with.
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How can I tell if they are worn?
 
Move the carriage up near the chuck. Snug down the gib screws until they are just snug enough that you can feel resistance when moving the carriage. Now move the carriage from one end of the ways to the other. Are there tight or loose spots during the travel? If there are slight changes in resistance then you are OK. If the resistance gets hard or goes away then you have wear.
 
Cvans said:
Move the carriage up near the chuck. Snug down the gib screws until they are just snug enough that you can feel resistance when moving the carriage. Now move the carriage from one end of the ways to the other. Are there tight or loose spots during the travel? If there are slight changes in resistance then you are OK. If the resistance gets hard or goes away then you have wear.
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I don’t know if my carriage has any adjustment, I am fairly certain it does not.

chieffan said:
One thing I did that helped mine a lot was replaced the gibs with brass stock.
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How did you cut the bevels? What does the brass do differently?
 
I tried to measure the dovetail (is that the name?) for the cross slide. The largest dimension I got was 1.819” and the smallest was 1.817” which I would say is good, but I am not sure. I measured the only way I could think of, I am not sure if it tells me much by doing it that way. The micrometer is not on the corner, it is as far into the groove as it would go.
 

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You measure dovetails by putting a hardened steel dowel pin on both sides, making sure it touches the bottom and the taper, then measure over the pins. That keeps you on the relevant wear areas.

The procedure Cvans posted will work well to let you know if its worn and where the wear is.
 
Ryan313 said:
I don’t know if my carriage has any adjustment, I am fairly certain it does not.



How did you cut the bevels? What does the brass do differently?
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Mine were only 4" long with one edge beveled. I did that with a file. The brass slides easier than the steel does. Especially with a little graphite on it.
 
I think this is likely my issue. I used a feeler gauge and the gap is 0.021” Would you guys just get some shimstock and make a spacer? Or isn’t there a better way to go about it?
 

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That's a pretty seriously worn leadscrew. You may be able to work around it by adjusting the endplay, either with an official adjustment from your refurbishment manual or the shim you mentioned. But the best way is to replace the leadscrew and nut. You should be able to find a replacement kit on eBay fairly reasonably.

If you do try the spacer, do all your cutting by moving the cros slide in only one direction, it helps to take up the backlash.
 
I have just looked thru this post reading about the finish and see that no one has mentioned tool stick out or keeping every thing close and tight. Best practice is to keep the tool as short as possible. Keep the cross slide and compound slide as close to center of travel as possible and tight. When doing a critical face cut I often tighten the gibs on the carriage and compound to lock them in place before doing the cut with the cross slide. Of coarse then I have to readjust those gibs after the cut is done. You quickly learn that there are no set and forget adjustments on a lathe. Don
 
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