I ran into this issue today where I was cutting a stepped pocket for a battery compartment. After the job was done I noticed that the corners were not square as I designed them in CC Pro V7. At first glance I was OK with it as it is a compartment on the bottom of a wood base and will not be seen. BUT then I noticed that one of the corners WAS actually square. WTH!?!?
At this point I had to try and fix it as it did not look good. After some manual work I was able to square up the other corners to match.
This is concerning to me because at times I am working on projects that I cannot afford to screw up. Is this a known issue?
A pocket on the inside will always have rounded corners. All inside cuts will have the radius of the bit for a corner. Outside corners will cut square if designed square. There is an option for rest machining if you have the pro version. The rest machining works like this. You cut a pocket with a 1/4" bit. And you have 1/8" radius corners in the pocket. Then you create a second tool path and pick rest machining and tell it the previous 1/4" bit and bit a smaller bit and just the corners will be removed and not the whole tool path. You still get rounded corners but they get smaller with each smaller bit you pick.
Thanks for the info. I am completely aware of the bit radius. I am not talking about that. When using a 1/8" bit I would end up with like a 1/4-3/8" radius. This has to do with having my speed settings too high (for my machine) in LinuxCNC. I am planning on testing the G61 and G64 setting in my G-code. Hoping that will fix the problem.
I have used the rest machining but I have found that it does not always do a great job. It seems to start and stop the cuts in the wrong places. It appears to start and stop the cutting too close to the corner leaving a small bump on each intersecting edge. After cutting the the corners using rest machining I have then had to run the smaller bit around the entire perimeter to remove the bumps that were left. Is there a way to have the rest machining start and stop just a little further from the corners?
