Damaged Sheldon compound

WesPete66

WesPete66

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Looking for helpful responses for what I've found on my Sheldon EXL lathe.
I found the end of the compound is bent downward, from previous crash/es into the chuck. Discovered when a new t-nut would not fit the slot. Disassembly made it obvious!
The bend begins by the pen in 3rd pic. But after cleaning l found a crack on both sides, even with the front surface of the T slot (just forward of that pen).
I expect the top of the compound cannot be flat.
So... Do l remedy it, or use it? Flatten by pressing? Mill a skim cut to flatten the 'ways' and the top surface?
Thanks!20241103_180918.jpg20241103_180946.jpg20241103_181019.jpg
 
The compound is cast iron and trying to straighten the bend would more than likely extend the cracks or completely break it in two. If you were to remachine the way surfaces, you will also have to include the dovetails. For the top surface, you would need to machine the T slot as well. After all that, you would probably end up having the cracks grow. A first step would be to have the cracks repaired, either by brazing or TIG welding. Then a full resurfacing to true everything up. Alternatively, you could be on the lookout for a used compound,
 
Another approach would be to make a new compound. It would be a fun project. If I were making it, I would lose the curved surfaces but if one was dedicated to restore the original appearance, they could be added,.
 
I actually have a similar issue on my Sheldon. As far as I can tell my dovetails aren’t damaged. I rough scraped the rotating part of the compound in to make sure it fits well with the cross slide. My cross slide was broken where the coming bolts and previously repaired. It was all out of whack and I was able to skim the top level in the mill. I didn’t worry about the round tee slot height on it. I still have .015” out of level on the top of the compound. It’s in my compound tool post tee slot. I’m going to mill it level. I will see about milling the inside of the tee slot to match but I don’t think I will have to. I think .015” of mismatch will be fine when tightened.
 
It’s been said before, but “ditch the compound and install a solid tool post.” Maybe this is a message from the gods to do so.

Since you didn’t discover this until adding a new T-Nut, the compound should be serviceable enough to use on the few times you need to turn a taper, and an 11” Sheldon is certainly rigid enough to cut threads straight in rather than at 29-1/2 degrees.
 
ChazzC said:
It’s been said before, but “ditch the compound and install a solid tool post.” Maybe this is a message from the gods to do so.

Since you didn’t discover this until adding a new T-Nut, the compound should be serviceable enough to use on the few times you need to turn a taper, and an 11” Sheldon is certainly rigid enough to cut threads straight in rather than at 29-1/2 degrees.
Click to expand...
Fyi I’m not the OP. I’ve thought about doing this on my sheldon. I keep my compound set at 29.5*. One if the reasons I haven’t wanted to do it is if I wanted to put the compound parallel to the ways to have accurate depth in Z axis without a DRO.

That being said I haven’t had to do that. Everything I’ve made is either accurate enough going off a scribe line or using the micrometer depth stop.

I do think I might make one though.
 
D.sebens said:
Fyi I’m not the OP. I’ve thought about doing this on my sheldon. I keep my compound set at 29.5*. One if the reasons I haven’t wanted to do it is if I wanted to put the compound parallel to the ways to have accurate depth in Z axis without a DRO.

That being said I haven’t had to do that. Everything I’ve made is either accurate enough going off a scribe line or using the micrometer depth stop.

I do think I might make one though.
Click to expand...
Check out Quinn’s & Joe Pie’s videos showing how they use a dial indicator for accurate Z travel.

Adding a scale to the carriage is relatively easy, even if you don’t go full DRO.
 
I wouldn't try to straighten it. I would just trim your T-nut slightly to fit, and not take any more material from the compound itself.
Then keep an eye out for a replacement on Ebay, or plan on making one sometime.
 
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