Question about an op please.

[boyd.sofield]

I have attached a file of a part that is simple but I dont understand. Operation #5 is a contour run with a slotter.

My question is about heights. I have set the bottom height which is correct. But the top height, in order to get the correct slot, I have to set an offset to 3mm below the top of the slot. The slotter itself, is has a flute height length of 5mm. I thought, the correct height for the top of the contour would be the top edge, minus the flute 5mm. But that does not work, in order for this part to machine correctly I need to offset the top height to 3mm.

I dont understand. Have I done something wrong? I can carry on offsetting the top of this 5mm high cutter to -3mm but that is silly aye?

[seth.madore · Accepted solution]

It comes down to math between the "Multiple Depths", flute length and Top Height. Toolpath is calculated from the bottom edge, but then it also factors in the aforementioned settings. It's a bit confusing, and certainly in need of some improvement.

[boyd.sofield]

Hi Seth. Ok so in a nutshell, there is nothing much I need to worry about? I did try to set the top height, off the bottom of the contour, but (plus) 5mm to account for the length of the flute. it wouldn't accept that. 

Ok so I wont try to understand why I put a 3mm offset into a 5mm flute but I will do it anyway ha.