Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: JTW on March 18, 2015, 06:47:55 PM

Title: Weird backlash issue
Post by: JTW on March 18, 2015, 06:47:55 PM

I had to set the backlash of an axis on our lathe to 0.5mm! There is actually almost no backlash at all, it's a ballscrew. After some messing about I found that the servo just doesn't react quickly. If I turn the handwheel for the axis I can go 45 degrees in either direction before the servo fights back. The weird thing is that axis does actually move in this time. This is consistent and the machine is accurate with the 0.5mm correction but clearly something is wrong here. Perhaps a software setting on the servo driver? I use CNCdrive from Hungary and the motors are SEM with Heidenhein encoders. Can anyone offer some insight please?

Title: Re: Weird backlash issue
Post by: Hood on March 22, 2015, 05:05:46 AM

Sounds like you need to stiffen up your motor tuning in the servo drive.

Hood

Title: Re: Weird backlash issue
Post by: JTW on March 26, 2015, 03:56:23 PM

Confirmed. Balasz from CNCdrive was very helpful and we solved the problem by tuning the PID settings. :)