I’m embarking on a project that requires a lot of very fine cuts in plywood and I’m wanting to eliminate chipout of the surface as much as possible. I’ll be using a 2-flute spiral upcut .0625" endmill.
I’ve got a few strategies for this that I’ve come up with (and some tested), but I’m interested what other ideas people have.
I’m going to pre-finish the surface of the material (water-borne poly or lacquer) prior to cutting anyway, I’m thinking/hoping this helps hold the fibers together.
Run two jobs per cut: The first an extremely slow (15IPM) and shallow (.005"), then follow up with full-speed/depth passes for the remainder. Idea being that it will score the material on the first pass, then not chip on the subsiquent ones.
Obviously, this is AN answer. I’ve got a couple in the right size, but I have a lot of linear feet of cuts to do and downcutting is just very hard on the mills. I also worry that this would result in some bit wander and the cuts need to be as precise as possible
Scoring pass with a Downcut endmill
Make the first shallow (.01") pass on every part with the DC endmill, then switch the tool out for the UC mill. My concern here is yanking around the steppers during toolchange and ending up a few thou off in some direction.
Putting a masking material of some kind (tape or film) overtop the surface of the material. I’ll use painters tape on wood when I need to help reduce chip-out, but I’m worried about this gumming up the endmill.
Those are all my bright ideas, mostly untested… eager for feedback…