The Home Machinist!

Has anyone drilled and tapped their lathe spindle? Is the steel particularly hard or difficult to work with? I'd like to do it in place - i.e. not remove the spindle from the lathe.

In this case it would be four holes on the outboard end to act as a spider. The lathe is a 15" Clausing-Colchester 8513 model.

Thanks,

Dave M.

You may find your spindle is hardened only where required. (the spindle nose and bearing seats). That's not unusual when hardening is accomplished by induction.

If so, the end of your spindle may not be hard at all. Give it a test with a file. If the file skips over the material easily, without cutting deeply, it is likely hardened. If not, you likely can drill and tap it with no effort.

Harold

I have done this on my Logan and it was not hardened.

An adapter that is a snug fit to the spindle and held with set screws, would be better, you can make the wall thicker to help the screws from canting and it will not be a permanent modification to the machine.

Thanks, guys. I had already done the file test but was looking for some anecdotal evidence that this had been done successfully and it is hoped, easily. The spindle has quite a bit of meat with the wall thickness being .340" at that end. That should enable the use of 1/2" X 20 TPI holes that will not wallow out in the short run.

Thanks again,

I like Deltaenterprizes idea, that way any timing issues between chuck and spider can be adjusted, if there are flats on the barstock (barrel).

As delta and olddog said haveing the timing, the spider bolts line up with the chuck jaws, will save you a lot of headace's when seting up/dailing in.

In regard to tapping the end of the spindle for a spider, why not machine a sleeve that fits over the bearing retaining nut (like a skf nut) and tap the end of the add on sleeve. Seems easier this way. gofer