3 out of 4 fillets have a different radius?! I can't understand why. Does anyone know?

Hi there Avid community,

As of recently inner corners come out very odd on my avid cnc. I am not sure where to problem lies. This goes for pockets as well for outer profiles. For instance when I have drawn a cad file, a lot of corners randomly get a radius way larger than needs to be. This happens in pockets as well, where 3 out of 4 pockets get a different radius than I have drawn in Cad.
I can’t wrap my head around why this is.

I have tried reinstalling mach4 twice(thought it might be corrupted)but to no avail
I have tried making the cad file in rhino and in VcarvePro. Both with same results.
I have tried test pieces with different bit sizes; if I am using a bit way smaller than needs to be I can get it to make a correct corner but any bit closer to the actual size the fillet needs to be and the corner becomes way large. I have added a picture of the Vcarve file; what the test piece should look like and a photo how it comes out. Does anyone per chance have seen this type of issue before or know what direction I should be looking? Any help is greatly appreciated.

Cheers from Amsterdam,


I have to add; dogbones and T-bones come out ok, just the normal fillets that form a problem. Also in this test piece the outside profile came out ok, but that is not always the case

That looks like you have path blending mode turned on, with way too high a value. This is G64 but I don’t know how mach3 supports that (I use linuxcnc, where G64 takes a parameter).

If the one corner that is tight is the one that it started the pocket on, then I would guess your CV mode settings are messed up. I am able to create that with VERY slow acceleration settings and really loose tolerance settings for CV in mach4. You would have had to run one of the CV wizards to change those though since the default values that come with the AVID build are good.

I can’t think of a setting in Vcarve that woudld do that, and even if there was, it should simulate it anyway.

On the other hand, if it were CV problems, then it really should show up in those two side pockets as well.

Have you tried someone else’s proven file?

Thanks for the replies guys, I am going to deep dive into each of your answers and get back to you