backlash compensation

[ychap]

thanks,
its not a backlash issue the technician came down and checked and changed all the transmissions, even not having the machine under load, just putting down a ruler and running a basic calibration test it we were able to get accurate to any specific number whether it was 12 inches or 30 inches, the problem was if you then tried to send it to a different number there was no consistency and we were getting up to .026 off, the technician then told me we're probably not going to be able to get it better than that its just how these cheaper ($25000)machines are made, i explained how that doesnt make sense , and he said maybe theyll work on a solution in the factory to get it better, and this was the solution they got back to me with, to map out the table in .5 inch increments and use the backlash compensation software, I was just reaching out because i thought despite what they were telling me, cnc should be able to do better than that without the software fix, and i wanted to hear other opinions if i should keep fighting for a real fix or a refund or allow them to just use this software to compensate for what i believe is a faulty machine.
thanks again to everyone!

[avp]

That's not the fix. Backlash compensation does not work like that. Sounds like they're just trying to push the problem on someone else. Not a very good tech in my opinion.

[ShawnM]

OP didn't mention backlash. He stated an accuracy problem that could be caused by wrong turns/inch, steps/turn, or even lost steps since this an open-loop stepper system. Without seeing a report, and actually testing backlash, and fine tuning calibration, everyone is just guessing.

He did mention backlash, the title of his topic is “backlash compensation” so maybe that’s where the confusion comes in.

If his over all turns ratio is off then he needs to go back and run the DRO Fine Tune procedure to dial it in.

[Nigelo]

To avoid everyone chasing their tails, Can the OP PLEASE post a current REPORT.ZIP If you don't know how to do this then please ask

Backlash compensation is NOT was is being described by the Agent. Checking each 0.5" of travel refers to Screw Compensation NOT backlash comp and might be appropriate in fault finding with a rack.

[ychap]

hi thanks yes sorry I must've caused some confusion by calling the subject "backlash compensation",
appreciate all the replies, I wasnt looking to diagnose the problem through the forum (although I really appreciate everyone's suggestions!)
I was just looking for educated opinions if I should allow them to use this compensation software to fix the machine, and also to get opinions if its ok to have a cnc come with that sort if discrepancy's.( which the company keeps telling me is normal) because when i looked into the software it seemed to be for ball screw compensation and not to help fix a problem created by a faulty rack and pinion set up

[cnckeith]

hi thanks yes sorry I must've caused some confusion by calling the subject "backlash compensation",
appreciate all the replies, I wasnt looking to diagnose the problem through the forum (although I really appreciate everyone's suggestions!)
I was just looking for educated opinions if I should allow them to use this compensation software to fix the machine, and also to get opinions if its ok to have a cnc come with that sort if discrepancy's.( which the company keeps telling me is normal) because when i looked into the software it seemed to be for ball screw compensation and not to help fix a problem created by a faulty rack and pinion set up

if you post a fresh report.zip we can help you mo better.