Help to stop backlash

Glenn here's your finished lead screw

When I received the parts it was quickly obvious that the nut wasn't worn that badly but looking at the screw that was badly worn at the length that gets all the action...the flat top of the acme thread had worn to a nice rounded top.

If the nut was moved to the unworn extremities there is hardly any backlash. I can only imagine that the nut is newer than the screw

The nut is a simple 1" diameter bronze threaded 10tpi 3/4 LH pressed into the holding block and a oil/grease hole through to the thread

When the table leadscrew nut stripped on my Dore Westbury mill , i obtained a 1/2 inch x10 tpi second tap and proceeded to tap a scrap bit of bronze to try it out , i found that it took so much force to make it cut even a few mm i was afraid the tap would break , but looking on a forum i saw a guy had used a hot moulding technique using polyacetal plastic to make a new crosslide nut for his lathe with good results and i had a bit of that plastic to hand albeit in bar form , it was easy to tap 35 mm of thread and completed and fitted to the mill works just fine , should cause less wear to the leadscrew as well ,

i found that it took so much force to make it cut even a few mm i was afraid the tap would break

With some jobs most of the threadcutting work is done on the lathe, and the final profile with the tap

I have just ordered from Automotion Components a one metre length of 16mm x 4 mm pitch left hand thread lead screw. Cost less than £14 plus vat two matching bronze nuts at around the same cost. With a bit of machining I will have new cross slide lead screw and nuts in the lathe for just over £50 Imperial sizes are available.

Do Automotion Components do imperial sizes? I dont seem to be able to find them online

Glenn wanted to keep his lathe imperial so his dials were as intended

Ian

Comes up straight away.

http://www.automotioncomponents.co.uk/en

Sorry, you meant imperial. Given that they are almost certainly made in China, probably not.

Edited By Muzzer on 30/12/2015 19:55:57

I'm sorry I must be dim where are they?

Had a similar problem a few years back on a friend's ML7, the thread on the lead screw on the top slide was so worn the top of the thread came to a sharp point. I found an old new lead screw and nut at the retail store that used to be the Myford agents in Christchurch (NZ), I paid the marked price (had to convert to $ & C) $NZ10, had been 5 pound. The old nut looked perfect, but I suspect it had abrasive embedded in it and it was working as a lap.

With the main lead screw, a way of doing a repair is to take it out, and turn it end for end, the tail stock end gets much less wear than the chuck end.

Ian S C

Or you could try this outfit, who list imperial **LINK**

Automotion are in Cranliegh Surrey. The parts are made in the UK . Make sure to put Automotion in the search not Automation. Good list of stocked imperial sizes and specials to order.