Backlash compensation: config option

[leaveme]

Hey guy's:

I have some backlash in my X and Z axis.
For one inch move, dial indicator shows 1.004" in X and 0.997" in Z axis. So the backlash is 0.004" in X and -0.003" in Z.
How do I configure it Mach3? Appreciate if someone can shed some light on this.

regards

[RICH]

in Mach:
Config>Backlash... put the backlash values  in for the axis, suggest 50% value for speed, click enabled and Ok, and then restart Mach.

RICH

[Overloaded]

Are you sure you are checking for the backlash properly ?
Looks like you may just be verifying the "steps per".
The indicator shouldn't read MORE than the commanded move in either case.
http://www.machsupport.com/forum/index.php/topic,12513.0.html

Russ

[RICH]

Hey Russ, thanks for the clarification.
Had the selective reading glasses on.....

RICH

[Jeff_Birt]

You cannot check backlash over a distance like 1" or more, if you try you'll start measuring pitch error in the leadscrew which is a whole different animal. To check backlash you run the axis a good distance (say 0.1") one direction to take out any backlash and preload your indicator. Then move in 0.001" steps the opposite direction. As soon as the needle move on the indicator - STOP - . The difference between the number of steps you made, lets say 5 - 0.001" steps, and how far the indicator moved, let's say 0.0005" is the backlash. You should repeat the measurement several times and be able to get the same result. If you can't get a reputable result then you have other mechanical issues that need to be resolved (something loose, flexing, etc.)

[leaveme]

You cannot check backlash over a distance like 1" or more...

Thanx Jeff. My understanding was something different
Your information really helps me. I'll try your advised way...

[Jeff_Birt]

When I first started out I tried a lot of things the wrong/hard way too.  It's all part of the learning process.