I bought 1/8" and 1/4" compression bits for hopefully clean top and bottom cutouts in Baltic Birch plywood. The upcut portion of each bit is 1/8" and 1/4" respectively. This means I would have to go full thickness to take advantage of the compression design. What speed (RPM) and feed (ipm) could I use on cutting the plywoods? Carbide Create library has much shallower depth of cuts of 0.03" and 0.04" for these bits.
For 1/8" ply/endmill I have used these settings successfully.
For 1/4" ply/endmill you may not been able to cut full depth, but you can still leverage a compression endmill for the finishing pass (to clean-up both the top and bottom edges at the same time). I’ll assume you want to do an external profile cut:
- in CC create offset geometry around the piece, say 0.02" outwards.
- create an external contour toolpath selecting that offset shape, and using a regular endmill (or the compression endmill if you want to avoid a tool change), at small depth per pass like CC recommends.
- create another external contour toolpath, this time selecting the original shape and full depth cut
The first toolpath will act as a roughing pass and remove material at the usual/safe/conservative depth per pass. The second toolpath will act as a finishing pass, it can run easily at full depth since most of the material has already been removed, and it will only shave off the remaining 0.02". And since you run full depth, you benefit from the compression endmill geometry, leaving you with clean edges
Thank you very helpful for a beginner. Great forum!
I use the cheap ones Julien put a link to. I run the 1/8"dia in 1/2" baltic birch
0.168" depth of cut
that way it only does 3 passes.
when cutting through I set my Z zero on the bottom.