Dealing with backlash

[cyclestart]

Recently bought a X2 mini mill with plans to convert to cnc. A Xylotex kit seems the simple control solution. The confusing part is the mechanical bits. Cncfusion offers a rolled ballscrew kit which sounds like a simple fit. Not sure if it will be accurate enough for interpolated paths? From the information available it seems the accuracy of the screws provided can be a bit "luck of the draw" .

This post from the emc mailing lists is a bit worrying
http://sourceforge.net/mailarchive/m...st.localdomain

Is backlash in Mach3 taken up more gradually? Some Mach3 users appear to be getting away with backlash well in excess of a thou or two..

One solution that comes to mind is going with the cncfusion kit and replacing the cheap ballscrews with better ones when available. Ground ones from ebay with a little luck.

Anyway, anyone here doing ok with larger backlash using emc ? My background with cnc is in a commercial enviroment so not use to thinking about backlash much.

[Al_The_Man]

You could keep an eye out for these to come up again, I suspect there will be more.
http://cnczone.com/forums/showthread...ighlight=hiwin
I have tried nook rolled and was not very impressed with the quality of the one's I got.
The one's this guy is selling is the next best thing to precision ground in my opinion, which usually cost a fortune.
Watch out for rolled that do not have a pre-loaded ballnut.
Al.

[kiwichris]

My current setup has .34mm (13.3 thou) backlash on the Y, and as it's relatively stiff it works fine... I'm just cutting wood and plastic on a router though, not metal.

If I climb cut across the 'Y' it will move a bit due to the backlash, but if I conventional cut it holds fine against the backlash, or at least seems to.. It's definately 10x worse if I remove the backlash settings from EMC..

You can set the rate the backlash step is taken up, although I've just left mine at the default that was in stepper_mm.ini.

Cheers, Me.