Letters getting busted out

1/8 endmill.
10000 rpm
Looks fine in create

Vcarve looked like it was gonna be messed uo ans this looked good. But this seems to be happwning even with big block letters.

Feeds.and speeds set my carbide motion

Anything im doing wrong

Your picture looks like plywood. So plywood is a thin veneer of good looking wood on top with layers below that are not as good at the top and bottom layers. When cutting on plywood the only thing holding on the top veneer is some glue. So if you cut a thin cut into the top veneer it is easy to get tear out. If you look at your “N” you can see the bottom and bottom parts of t he N are missing. Since the cutter is cutting along the grain and then turns to 90 degrees I would suspect the parts of the N were ripped off when cutting cross grain.

Make sure you are cutting with sharp tools. Make sure you are cutting through full levels of the plywood so you get the added stability of at least two layers of plywood. Just remember plywood is not the best material for a CNC due to the inconsistencies of the layers and the difference of quality in construction of different plywood sources.

A downcut bit might be OK, but plywood is always hard to get fine details in. If that’s a 1/8" kerf, then the details you want to get are likely just too small for plywood to hold.

To reduce tearout in plywood, you can try a downcut bit like others have recommended, or use a smaller bit to cut an inside profile of all of the letters and then go back with the larger bit and pocket the rest of the letter without any tearout because the fibers have been cut already.

You could probably use these 0.0625" downcut bits to safely cut out those letters. You can buy them individually, but I usually buy them 10 at a time.

A method I’ve found to work well is to take a nice sharp 20 degree V-bit, engrave the outline of the letters to a depth of about 5-9 thou. and then carve the letters out. This seems to eliminate chipout very effectively. Attached is a picture of a simple coaster I did with this method.

The material is plywood.


This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.