Cutting letters

Hi! I’m new to CNC and having a hard time cutting letters. I’m using a 1/8 compression bit and sand my letters very good. Everything looks good until I go to paint and glue them. Then it looks like on of the layers of plywood I’m using become frayed and make my design very sloppy. Not sure if I’m using the wrong wood or what? Any help would be appreciated!?

In addition to the sanding I find running a fine file over the cut edges to imperceptibly chamfer them addresses such issues — spraying with a transparent fixative to make such fibers stiffer helps as well — when you do that you can make an all but vertical pass to clean them up.

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I use this technique when I make cutting boards: I go over the wood with a lightly dampened cloth to raise fibers prior to the final sanding pass and coating. This kind of simulates that first “wet” cycle. You may want to try this with your projects.

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A compression bit is designed to cut full depth on one pass. The upcut at bottom would make bottom not have fuzzies. The top of bit down cuts making fuzzies not appear on top. The center part is cutting the center out. However on cnc you are not making full cuts on 3/4 material a compression bit is designed for. So the top is being cut with upcut raising fuzzies up and since your letter looks thin you are most likely cutting all upcut.

Try another bit and see how the outcome is. There is no bit that makes your work ready for finish without some hand sanding.

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