Cuts too wide - help with settings

[sshwarts]

I'm hoping someone can help me diagnose a problem I'm having with consistent cuts. This is a piece I'm cutting out of acrylic.

All of the notches are of the same width on the drawing and appear to be the same in LaserCad. However when the piece gets cut, the notches at lower right and upper left are wider. You might also see that there's some rounding of the corners at those two. The cut order (if it matters) is counter-clockwise starting at lower left.

Anyone have any ideas on what settings could effect this?

Thanks,
Scott

[Tech_Marco]

Scott:

What speed did you use? Did you calibrate the 'um'?
Do a few tests:
1) Draw a square with 20mm x 20mm and cut it and check the result. Do it in four corner
2) Draw a perfect circle like a 20mm in diameter and check the result. Do it in four corner

Then tell me what you got


Marco

[sshwarts]

Marco:
It appeared to be two things. One was that, yes my steps were slightly out but also our good old friend, backlash. I made some changes to the part that supports the belt pulley end to stiffen it up and helped a lot. Thanks for your help.

Scott