Cutting letters from 3mm Sintra (pvc)

[mklafehn]

I am trying to cut some 3-4 inch letters out of 3mm PVC and I am getting alot of scallops/ridges on the letters. I tried different speeds 2 and 4 ips and am using a 1/8" bit from Onsrud made for PVC. Any suggestions on getting a nice clean edge?

[Brady Watson]

Slow your move speed down (but not too low...you want nice big chips), use a straight cutter (no spiral), use arcs_inch post processor if using PW or ArtCAM. Check to make sure that your gantry & Z-axis is tight.

You aren't going to get away from the ridges in plastic...are you using a PRT or Alpha?

-Brady

[mklafehn]

I reduced the speed to 1 ips and it all but eliminated the "scalloping'.

I am using an Alpha. The letters look very clean now.

Thanks for the help.