[cromag27]

very frustrating issue. some of my cuts are not the exact measurements i need them to be. for example - if i cut several pieces that are 8x10, some are 1/32-1/16 longer than what's in the file. i ran several tests and i *believe* i have narrowed down the issues, the cuts going horizontal to the machine are a little longer than when traveling vertical. not sure what's up here! any help would be appreciated, thanks!

next wave shark hd3 ext
cut2d pro
i cut mainly acrylic but this issue happens on different thickness with different size bits, so i don't believe those are factors.

[awerby]

That could be due to backlash. Backlash is the error you get when a screw changes direction. Since there's a little gap between where the screw threads bear on one side of the nut's threads and the other, the motor will turn a little before the threads engage. Expensive machines have ball screws using double or preloaded nuts that have little or no backlash; cheaper machines have to deal with it. CNC control programs have ways to compensate for it, but you need to measure it accurately first, before telling the program to add a certain number of steps when the screws change direction.

It could also be that your steps-per-unit settings are a little off - that would be the first thing to check, before dealing with backlash.

[cromag27]

That could be due to backlash. Backlash is the error you get when a screw changes direction. Since there's a little gap between where the screw threads bear on one side of the nut's threads and the other, the motor will turn a little before the threads engage. Expensive machines have ball screws using double or preloaded nuts that have little or no backlash; cheaper machines have to deal with it. CNC control programs have ways to compensate for it, but you need to measure it accurately first, before telling the program to add a certain number of steps when the screws change direction.

It could also be that your steps-per-unit settings are a little off - that would be the first thing to check, before dealing with backlash.

thanks for the info. i researched backlash and that led to me checking all the bolts. some where loose. although i’m not quite sure where the t-nuts are. i’ll also look into that setting. thanks!