Anti-backlash on Taig mill

bjammin@... wrote:
Subject: Anti-backlash on Taig mill

Even if the screw is tensioned, that has no effect on the lash at the nut,
none!

[The tensioning Steve refers to will tighten up the screws. If they are too
loose, there will be an error introduced, because of the screw flopping
around, but this isn't the same as backlash, which is the error caused by
the difference between bearing on one side of a thread and then changing
directions and bearing on the other. The screws are adjusted at the factory,
and there should be no necessity of tightening them further. If you make
them too tight, you will impair the function of the machine.]


At 10:51 AM 5/13/02 -0700, you wrote:

>Steve Blackmore writes:
>>The ends of the screws have a ballrace which is tensioned by the
>>endnut - this removes the backlash - isn't this good enough for you?
>
>I have a Taig mill, it has 1/2-20 leadscrews and a brass(?) nut. The

screw

>is supported at the motor end, not at the end opposite the motor.

[It is possible to eliminate some backlash (down to .001 or so) by adjusting
the setscrews in the split bronze nut, which is supplied with the CNC and
CNC-ready mills.]

>
>Where are the tensioning screws you mention and the ballrace?
>
>Elliot Burke

Steve Blackmore <steve@...>
Subject: Re: Anti-backlash on Taig mill

On Mon, 13 May 2002 16:07:51, you wrote:

>Even if the screw is tensioned, that has no effect on the lash at the nut,
>none!

Not a screw - it's a nut????

It preloads the thread against the nut - I admit it's not "true
anti-backlash" but loosen it off and see what happens ;)



Steve Blackmore

[Again, it's possible to make the screw too loose (by cranking the nyloc
nut) and cause errors, but you aren't really preloading the bronze nut when
you tighten it, since it is essentially floating on the leadscrew. If you
really want to get rid of all the backlash, try hanging weights off the x
and y axes, so you're pulling the threads against one side or another.]

Andrew Werby
www.computersculpture.com