Well, I have a 1961 10L, dbl tumbler gearbox that came equipped w/ a 1-7/8 x 8 spindle. I had to look at a few beaters, but I eventually found a 2-1/4x8 spindle that was a direct drop in. I dropped the spindle in with the bearings it came with. Had to do a couple iterations of headstock bearing/shim adjustment (per the SB manual). But I ended up with 5C capability and the machine is so much more flexible now. I wouldn't go back.
In hindsight, I should have undertaken some sort of study w/ regard to eccentricity and repeatability using collets for the small spindle. just for my own knowledge. As collet repeatabilty is not perfect w/ the new spindle. Was the old spindle better? Don't know. my collets are all used too. Who knows.
What I mean is, I turn a piece in a collet, release and remove, then replace. And *sometimes* I'll get runout 1" out from collet in the .001-.002 range. Yet the majority of times it is less than .001.
My machine is a former school machine. The replacement spindle was not the best. But it has been adequete. And overall a great improvement.
If you plan on doing this swap I would plan on inspecting a couple spindles. I mean buy a few. Mic them in the bearing areas w/ a .0001 mic. Characterize the wear. After doing a couple you'll see some have lots of wear, some have almost none. Examine the collet taper region for abuse. Compare them to what you have.
I think their is an LOO spindle on ebay now. the ones you don't use will always sell on ebay. They are out there. I bought mine from Dave Sobel.
If I had it to do over, I'd hunt down a d1-4. But I have other projects and not enough time. Read a garage renovation, a shaper, and 10EE that want attention. If I run across a nice D1-4 headstock, I'll probably grab it for later on.
For now, the machine works. In its new place in the garage it turns very accurately (a few .0001's over 6" in a chuck) and its my primary lathe.
The conversion was worth it. Was relatively easy to do. The only special tools you'll need is some gear pullers to get the cone pulley and the end gear off. plus your usual selection of hand tools. And a selection of shims for spindle adjustment. I cut out all new ones as I had plenty of shim stock available to me.
its a great lathe. Probably won't sell it anytime soon. I've got just about all the tooling for it I'll ever need. Its currently setup now to modify chanters for bagpipes. Here's a pic...
Mark
