Cutters for Clean Edges on Maple Plywood

Advice on tooling and CNC settings for sharp cuts in plywood. October 15, 2009

We just ran our first nested sheet on a Komo VR 510 router, and I'm not pleased with the edge quality on prefinished maple plywood. We ran at 850 ipm and 18,000 rpm with an Onsrud 3/8 compression bit. I'm not sure of the exact item number as it's not my router. Can anyone who is running prefinished maple plywood and is happy with their edge quality chime with the necessary information to get us going in the right direction? Cutter type, feed speed, rpm, cutter direction, etc are well welcome.

Forum Responses
(CNC Forum)
From contributor K:
I use the Onsrud 60-123mw 3/8" comp on 3/4" prefinished maple all the time, 600ipm/15500rpm and get an excellent quality edge, especially when the bit is new. I'll go as much as 100 sheets with some loss in the quality of the edge but still acceptable for edge banding.

From contributor M:
Contributor K is right on. You can also increase the RPM as long as you increase the IPM proportionally. There are two other issues at play here - first and foremost, sharpness. Fuzzy edges, and especially "ridging" caused by compressing one layer and pulling at the other while cutting is a classic with any VC material. I can guarantee that if you look at the issues you are having with the edges, they will be on one layer on a cut in the X direction and the opposite layer cut in Y. This is because the grain direction in the plys rotates by 90 degrees.

The other is the species of the core of the VC sheet. Any core should cut fine with correct feeds and speeds and sharp tools, but some materials are more forgiving than others. I find that in general, more plys cause less problems (mostly because they are thinner and the ridges are therefore smaller), and that fir cores cause less issues than poplar or aspen cores (I guess fir compresses less because it is harder). If I have a choice I will get a 9 or 13 ply fir core sheet before a 5 ply poplar core sheet.

From contributor G:
I suggest using a 3+3 with serrations. We have hundreds of firms using this type of tool, with a perfect edge finish.