South Bend Heavy 10 Compound Slide

I've been lurking on this forum for a long time. Over the last couple of years I have picked up a Bridgeport knee mill, and now a South Bend heavy 10 lathe. I just got the lathe powered up using a VFD, and I have run into some issues. The biggest one right now is that is looks like the screw mechanism on the compound slide is stuck, and it's missing the dial. When I turn the handle, the slide moves but at the same time the screw comes out.

From what I can see, the handle should turn independently of the threaded portion, but they are stuck together. I can't tell if there is a set screw holding them together; the hole is too deep to see in and no allen wrench fits. Any advice is appreciated.

Thanks
Ken

Somebody else with a Heavy 10 will be able to confirm, but I recently disassembled the compound on my 9A and it looks like they have a similar design. The screw should turn independently of the collar. The holes on the outside of the collar are for a spanner wrench, and the collar gets tightened against the compound. In my case, the hole in the compound above the collar had a set screw in it. If the hole is tapped on your compound, you're probably missing a setscrew. Other designs may be different though since the rebuild manual I have for mine doesn't mention a setscrew in that hole, and I messed up a good chuck of the threads on my collar trying to remove it with the set screw tightened. After it wasn't releasing I stopped and investigated, and found the setscrew. The manual is pretty good at all the other details, so I thought the hole was for oiling the compound screw where it passes through the collar. Since your threads aren't messed up, I doubt there's a set screw in there. If it isn't threaded, maybe it is for oiling since there appears to be a hole in the collar that matches up with the hole in the compound. In that case, I would suggest trying to hold the collar with a spanner while you turn the hand crank and see if it breaks free. You just need to be careful to not over torque it if it doesn't.

yeah you're missing the dial as well. The bushing should unscrew from the compound after you remove the crank handle, then the screw will come out of the compound. They should not be stuck together. Probably just dirt, rust, and petrified oil if I had to guess. Hole on the larger ring is for a holding spanner, hole in the threaded area is to let oil get in there once the set screw above it is removed. The set screw isn't really so much to retain it, though it will help with that. I'd use a brass tipped one just so it doesn't mash the threads on the bushing over.

The bushing should stay in the compound on it's own. Normally you just spin it in there by hand and very lightly snug it to keep it still. The screw just passes through it and it serves as a bearing. The missing number dial does act like a thrust bearing though, so without it you've got some 1/2" of slop in that screw before the handle hits the bushing. Need to get one, or at least make up a spacer for the time being. Its nothing special, just a disc of metal really. The only "magic" is the numbering which you can do yourself if you're patient enough and have some means of indexing 100 lines accurately. I've seen it done using a saw blade as the indexing mechanism but I hear that huffing spray paint is a cheaper way of driving yourself insane.

sound to me like the handle shaft is bent and is bound up in the bushing.

You'll just have to take the whole thing out of the casting,take it apart and see what's going on.

Thanks guys. I found some spanner wrenches on eBay and will use those to try and get it apart. I bought the lathe at auction, and it wasn't the most well taken care piece of equipment. It was being used for wood turning. There is a lot of caked on wood particles everywhere. In the meantime, I will continue to apply some oil and see if it loosens up. There seem to be plenty of used parts online, so I will also replace the dial.

Ken

BB69 said:

Thanks guys. I found some spanner wrenches on eBay and will use those to try and get it apart. I bought the lathe at auction, and it wasn't the most well taken care piece of equipment. It was being used for wood turning. There is a lot of caked on wood particles everywhere. In the meantime, I will continue to apply some oil and see if it loosens up. There seem to be plenty of used parts online, so I will also replace the dial.

Ken

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I got the screw freed up by simply clamping it in my mill vice with smooth jaws and turning the large collar. There was a little bit of rust on the shaft that some oil and a wire brush took care of. It works well now. There is a lot of backlash, so I will probably look for a new nut. Otherwise, I will pick up a new dial and it should be good to go.

Thanks for the help.

Ken