PVC Carving

Did a test carving on PVC/Sintra today. Used a work piece that served as a waste piece when I did some airbrushing to see how it would come out. I have a few questions before I carve the real thing.
Material: White PVC 0.25" thick
Project size: 18.25 x 10.75

Large area clearance: 0.25 EM Upcut, 4 Flute
Clear pocket: Offset, conventional
Pass depth: 0.06
Number of passes: 1
Stepover: 25%
Spindle speed: 11,000
Feed rate: 120 inches/min
Plunge: 20

Second Tool: 1/16" EM Upcut, 2 Flute
Pass depth: 0.06
Number of passes: 1
Stepover: 10%
Spindle speed: 11,000
Feed rate: 50 inches/min
Plunge: 10

As you can see, the cuts are not at the same depths on the large area clearing, and the detail cut is not 100% even to the clearance cut. Also got some fraying. What am I doing wrong? Granted, I am not using the highest quality bits, but I wouldn’t expect the cuts being so uneven. Something off on the machine alignment? Wrong bits used? Too much stepover? Thanks for sharing your insight!

This is how I ran my last PVC (see below), total depth of cut .05. I ran the detail pass before the roughing pass. I am using inventable 2 flute carbide straight bit and the amana 45. I always do the roughing so it runs two passes.

Be sure to use the probe and zero out in the same location. I have done a lot of these search forum “Steve’s Projects”


Thanks Steve,

I design in VCarve and then import. Perhaps I should just do it in Easel like you did. What’s the diameter of the bits you used? Keep in mind, the workpiece is rather large. Still to get the corners tight I had to go with a 1/16 on the Detail. And what is the offset, or does Easel set it?

Super interesting on running the detail bit first and then two roughing passes.

And I am going to need to bite the bullet and buy that pricey but, aren’t I? Use only on pvc and should last a long time.

roughing was 1/8" bit, detail 45

I did it before with the Whiteside 60 as well, I have been been using my Amana 45 on wood and PVC. The Amana is crazy sharp.