Help with drill-Mill conversion

**Ross77** · 28-06-2009

How about using a Delrin nut instead of the brass(?) one (or a second nut made of delrin to remove backlash)

Cheers. The originals are cast iron, will the delrin be strong enough on their own if I replace them?

Wheres the best place to get ready made ones? as the thread is imperial (1/10 inch) Or is it still cheaper to buy a tap and make them my self?

**BillTodd** · 28-06-2009

I'd guess they'd be strong enough, although wear rate might be high.

I think one of the guys on the forum has been making and selling them (I don't know whether he has the correct tap for your threads)

What diameter are the lead-screws?

Are the nuts cast in place or are they removable?

Pictures would be good.

**Ross77** · 29-06-2009

Ok you'll have to excuse the photos and the state of my workshop. For some reason if i dont use the flash then there not in focus..:cry:

The screws are 16mm dia. (15.65 on the calipers) and have a 2.54mm lead (imperial 0.1") Cleaned and polished the screw so thats looking better but just noticed the nut has cracked where I have been tighting the pinch bolt, so definetly need a new one, ups.

The nut on the x axis is removable and the y axis is fixed.

Ive had a quick look on tinternet and found lots of different ideas but I'd like to know If any one has a tried and tested method, I've fitted bearings to the screw which was a major improvement, so just need to sort out the backlash in the nut..

Hopefully when its finished it should be a good MILL.....

**John S** · 29-06-2009

Screws are 5/8" x 10 tpi not metric,
Unfortunately 5/8" usually comes in 8 tpi.

Is it definitely an Acme screw or square thread, acme has tapered sides at 29 degrees ?

Then are they both RH, LH or one of each.

**Ross77** · 29-06-2009

Screws are 5/8" x 10 tpi not metric,
Unfortunately 5/8" usually comes in 8 tpi.

Is it definitely an Acme screw or square thread, acme has tapered sides at 29 degrees ?

Then are they both RH, LH or one of each.

Bugger.. I thouht Acme was square, and trapazoidal had the taper?

Anyway they are square and both RH, y axis moves correct but the x is opposite to the lathe (clockwise rotation moves it towards you)

**John S** · 30-06-2009

Square is square.
Acme is 29 degrees and usually imperial [ not always ]
Trapezoidal is 30 degrees and always metric

Let me have a look tomorrow to see what taps I have, definitely got 5/8" x 8 LH Acme but not sure on the rest.
.