Hi,
I have a strange inaccuracy in the parts I cut. If I cut an outside profile, for example a rectangle, I get the dimensions about 0.06mm larger than programmed. If however, I cut an inside profile, for example a rectangular pocket then the dimensions are about 0.05mm smaller than programmed.
My backlash is less than 0.015mm on both X and Y. If it were a backlash issue then, the axes would move less than the programmed distance. But it is not the case when cutting outside profile - if it were backlash, the dimensions would have been 0.015mm less than the programmed, but instead they are 0.05mm bigger. Also in case of backlash, the pocket dimensions would have been 0.015mm smaller, but they are 0.05mm smaller.
I thought it might be a lack of rigidity on my little Emco, but trying to rerun the program to see if it removes more material, it only improved the dimension by 0.01-0.02mm, i.e. from 0.06mm discrepancy to 0.04mm. Subsequent rerunning the program doesn't seem to remove any material.
I was experimenting with aluminum and not cutting too deep, so really seems unlikely to be a rigidity issue...
Any thoughts are appreciated.
Thanks,
Daniel