cmfalco wrote:Bob.Murphy wrote: In any case, the only way you'll know if you succeeded is after you've made the nut and disassembled the lathe to test its fit on the shaft. Given this, something to think about is buying a tap that would give the tightest fit (i.e. having the class of fit giving the smallest ID), making the nut, disassembling the lathe, and testing it. If it gives an acceptable fit, great. However, if the nut you just made is too tight it now is a no-go gauge, and if too loose you can use it to judge how much smaller it needed to be. Then reassemble the lathe and make the next nut with an indexable threading bar using the information obtained from the first nut.
Fortunately I don't need to keep assembling the lathe in order to make the parts:
Having two lathes is a bit of a luxury but on the Denford I can 'dial-up' 48 imperial threads (4 TPI to 224 TPI ) whereas on the Warco I have to spend an hour assembling some rather ropey Change Wheels. It can do both Metric and Imperial which is a boon.
If I can make an adjustable tool holder for internal boring I'll be "Sneaking up" on the size - trying it as I go.
The idea of an ' adjustable split nut' is a good one. I'll seriously consider that.