[mhackney]

I went back and re-did the part in BobCAD as I suspected it might have something to do with inexperience since this was one of the first parts I experimented with but never actually cut. This time it seems to work, I haven't cut yet but I ran in a local simulation copy of Mach and it didn't balk. Unfortunately, I don't have the old version so I think I'll just move on and call it "experience".

I did run into an odd thing though - the 1/2" hole on the left edge of the part is roughed as a pocket with a finish profile pass. I used the Spiral option for material entry with the default .25" radius. Even with simulation I did not notice that the roughing was actually cutting a much larger pocket offset from the center. So I ended up with a much larger hole that is offset. I would have expected BobCAM to report that the cut was going outside the boundary. Now I know to pay close attention to these things.

I use this hole as my datum and probe to find its center. I have a couple of options to fix this. I'm leaning towards milling a larger .9" hole offset so the incorrect hole is completely removed. The only reason I need to do this is because the finish pass took a little crescent out of the right side of the pocket so it is not perfectly round along X. In practice this should not cause a problem since I could still probe the middle and all of the hold down locations will be bored after probing. But I'm a bit of a perfectionist so I think I'll overbore the hole and adjust my part offset by .1" (which is what I determined by measuring) and go from there.

[The Engine Guy]

I went back and re-did the part in BobCAD as I suspected it might have something to do with inexperience since this was one of the first parts I experimented with but never actually cut. This time it seems to work, I haven't cut yet but I ran in a local simulation copy of Mach and it didn't balk. Unfortunately, I don't have the old version so I think I'll just move on and call it "experience".

I did run into an odd thing though - the 1/2" hole on the left edge of the part is roughed as a pocket with a finish profile pass. I used the Spiral option for material entry with the default .25" radius. Even with simulation I did not notice that the roughing was actually cutting a much larger pocket offset from the center. So I ended up with a much larger hole that is offset. I would have expected BobCAM to report that the cut was going outside the boundary. Now I know to pay close attention to these things.

I use this hole as my datum and probe to find its center. I have a couple of options to fix this. I'm leaning towards milling a larger .9" hole offset so the incorrect hole is completely removed. The only reason I need to do this is because the finish pass took a little crescent out of the right side of the pocket so it is not perfectly round along X. In practice this should not cause a problem since I could still probe the middle and all of the hold down locations will be bored after probing. But I'm a bit of a perfectionist so I think I'll overbore the hole and adjust my part offset by .1" (which is what I determined by measuring) and go from there.

Hmmm, as you haven`t uploaded a file or images no idea really what you are talking about

Usually if you are going outside a hole with a spiral entry the spiral radius is too large

Only think I can think of with the drilling cycle is that on the machine you will have set a Part Zero, if that isn`t set to Z0.00 then you could have a problem I assume testing on your desktop you haven`t set that ? ?