I'm getting this problem when making pockets.In the corners it's removing too much wood. It's like it over travels. The pictures I added show it really well. I've checked the machine for anything loose and looking for slop and it's fine. I'm at a lose for why it's doing that. Edit Bit is .50 or 1/4 " inch in diameter. The corners are square so Im running the bit into the corner and getting an 1/8th inch radius from the bit. I'm hearing online that one way to stop it might be to use a smaller bit. Another suggestion is to slow down the feed rate into corners.
It's a reminder that no matter how rigid we think something is, there is always a certain amount of flex - even within the tool itself. The cutting forces are pulling the tool into the corner, and then they change abruptly by 90 degrees, leaving a witness mark. Even if you take a light pass, the tool suddenly sees 90 degree engagement at the corner that results in a spike in machining forces, causing a similar problem (and also possibly breaking tools, especially when machining metals). Using a smaller bit (on its own) will not fix this, since the CAM will just drive it further into the corner. Add a radius to the corners of your CAD model that the tool can follow, and use a tool that has a smaller radius than them (or make the radius of the corners larger than the current tool - e.g. 4mm radius corner for a 6mm dia / 3mm radius tool.) In addition, you could try and reduce cutting forces by using a 'roughing and finishing' strategy (machine out the pocket leaving a small amount of material to be removed by a finishing pass) and/or take shallower cuts if there is still a problem, but control the radius first.
