Vintage Windmill and Wind Generator Forum

Kenneth, I've found your posts and have read them over to the point where I about have it committed to memory. I think I'm good to go but will probably have more questions once I get into it.
Thanks again

-RP

Windy , you really are needed !

I enjoy helping. Thanks.

I got most of the rust off of the upper turntable race and as you can see, there's a lot of divots from the balls. What would cause this on just one side? Tower wasn't level or something causing the gearbox to be out of balance - or just the nature of the beast?

Anyway, I'm going to fixture it on a faceplate on the lathe and see if I can true it up so that it'll turn smoothly.

-RP

If those are anything like Dempster turntables, they are hardened cast. Very difficult to machine.

Be careful turning turning down that bearing plate if you go to far the two plates might rub together. Just my thought !!

Prevailing wind might cause more wear on one side…that is my theory.

I'll know in a few minutes. I can turn the lips down a little as well to make sure that the only metal to metal contact is ball on race. If worse comes to worse, I'll get a new one but I figured it may be worth a try to save this one.

Thanks all
-RP

It is very common for Dempster turntables to drag. The bottom cup can be trimmed 1/8 or 3/16 to relieve the problem. If you decide to trim the lower part, if it's a cup, don't forget the inside circle also.

Well, it seemed to turn ok. The ball seat shaved off pretty easy. I pecked away at it with a button insert until most of the divots were gone and I had a good fit with a radius gage. I did shave some off from the inner lip but man oh man it was some hard stuff. I was using a carbide button insert and it was producing purple shavings and a few sparks but I managed to shave about about a sixteenth off. It left a mirror finish on cast, so it was pretty hard. When I put it together with the ball bearings I've got about an eighth inch clearance on the inner edges and a little less on the outer edge and it turns nice and smooth now. If I put some downward pressure on the outer edge of the upper race, I can get it to wobble a little bit, but I imagine that's what the centering spider/storm stay is supposed to prevent.

-RP