Milling PVC Foam with an Aluminum Laminate Face

Selecting the right tool and cutting in two passes are the keys to success. October 15, 2009

Question
I am CNC routing foamed PVC 12mm with aluminum laminate. I’m doing this in two passes but am having problems keeping the aluminum edge clean. The aluminum is face down on spoilboard so we can insert holes for mounting purpose. We are currently using 1/4" super O cutter from Onsrud but can’t seem to resolve the problem. Does anyone have any suggestions?

Forum Responses
(CNC Forum)
From contributor M:
The best suggestion is to view the two materials as separate operations and cut the foamed PVC away with the spiral O, then do the aluminum laminate with tool, feeds and speeds more appropriate for it without the foam.

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From contributor G:
There are a couple of designs for the O flute. The feed speeds vs. rpm's on your tool maybe incorrect.

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From the original questioner:
Thanks guys things are going well now. I’m using 1/4" upcut end mill at 4200mm X 18000 rpm cutting away 11.5 mm of foam first. The aluminum edge looks good.