Cross Feed Reassembly Question

As I am re-assembling the cross feed on my lathe after terardown for cleaning I see that there are a pair of small holes drilled through the bushing (item 20 on form 911J) that threads into the saddle to support/guide the cross feed screw. The holes lines up with the oil hole in the top of the saddle, but only if I back the bushing out about 20 deg after it bottoms out. I see the same holes in the similar bushing on the top compund (item18 on form 948D), but for that bushing, if I line the hole up with the oil hole (at 12:00 position), the zero marker scrribed in the bushing lands at 11:00 instead of 12:00.

My question: are the holes supposed to line up at 12:00 so the oil fed into the oil port drips directly onto the cross feed screw where it sits inside the bushing, or is the oil supposed to roll down the top of the bushing and eventually find the cross hole?


Thanks
Chris

Chris, you should keep the oil holes as close to TDC as you can, but they will still oil, I
believe, if not too far off. Just test it by mounting the bushing only, oiling through the hole
after you have inserted a 3/8 rod in place of the cross feed screw. Pull the rod and see if it oiled. As long as the hole is not close to 90 degrees it should find it's way in. It is not
hard to correct the hole position by facing the bushing where it mounts, although you will
have to remark your 0 witness on the other 180 degree (aprox) side.

Steve Wells

Cross Feed

Thanks Steve,
I left the bushing threaded in so that the oil hole is lined up at the 12:00 position. Its not that far off from fully seated home, so I think I'll just leave it like that.
It seems some one lost the adjusting screw for the gib in the upper portion of the compound and substitited a cap screw and nut.

http://i172.photobucket.com/albums/w26/ChrisK_09/GibLockSscrew.jpg

Of course it's only 50-50 chance that the nut stays put and the gib gets pushed along, so it has been sort of frustrating to get it dialed in. I guess I could just Loctite the nut in place, but I would rarther make a a better/real one. I was plannig to copy the design of the adjusting screw from the lower compond which was still there, but wondered if anyone has a photo of the correct screw or dimensions?

Thanks
Chris

What Model SB

What is the model South Bend Lathe that the compound is off as I have on in Australia that is going on a Hercus (South Bend Clone) and looks identical with the original screw. I can take some measurements for you tonight.

Regards

Sparrow

It's interesting you should ask this (original) question Chris as I have precisely the same situation with mine and wondered how it got that way. When making a replacement bushing you'd generally spot through the oil hole but I wonder now if they were simply drilled off the machine in "about" the right place?

Pete

Compound Questions

Sparrow,
This is a 10L, model 187ZN.

Pete,
I agree, and yet, with all the care SB took in manufacturing all the other parts, it seemed strange that "close enough" would apply to this bushing?
As I'm taking this apart for cleaning/repair, I'm getting the idea some one already went through it once before. There are too many socket head cap screw holding parts together where I think SB would have used slotted cheese/filister head screws. This compound assembly once had a taper attachment that was broken or cut off, so this parts may not be original. So if this bushing is a replacement from another lathe, it would explain why its off a bit.

Chris

Where oil goes thru a threaded bushing like this, some machine manufacturers turn a groove around the bushing, removing the threads in that area. You could also just grind a part of the thread away to ensure a free oil passage. It should be fairly easy to fabricate a thin shim or machine the bushing shoulder to restore the original registration of both the hole and the witness mark.

On my heavy ten, that's what the manufacturer did, I think.

I can't see the hole in the bushing when I remove the oil screw, but
when I fill the hole with oil, it drains down in, and shows up at the
appropriate places.

I think there is that groove that lines up with the holes in that
setup, at least in the 10Ls.