[dlaery]

I am using a 1/32 ball end mill on alum, using the Equidistant offset with a step over of .004" and in the allowance -.002", does that mean it is cutting .006"?
I am trying to understand stepover, is stepover down and over .004?

[BurrMan]

Stepover is the space between the equal distance passes. The allowance is to leave stock after doing an initial material removal, to run a second pass with a smaller stepover, to get a better finish.

There is no "down" or depth option. It is a surface based toolpath that gets its depth from the driving surface.

I don't think the "allowance" being set as a negative number is an intent. It WOULD be interesting if it was offsetting the surface in more, though, but I wouldn't be surprised with erroneous results...

[dlaery]

ok thanks, that helps. I have given you explanation a lot of thought and I understand why it is stepover only. I thought it had to go down also but I can see that now.
I attached a pic of what I cut.
This is a fishing lure mold to pour lead in and sometimes it does not weigh enough and that is why I use the negative allowance to make it slightly bigger and this works.

[jrmach]

I think it would be better to "lie" about the size of your end mill

[Beansdiesel]

The thing you have to watch with a Surface base TP and using a negative allowance is it will throw off your radius's and diameters or your 3d part. But it should work for what you are trying to do just fine.

Another toolpath you an try on it is Project Curves and select the Offset setting and set a number of offsets along with a step over distance. Depending on the part I like using it better then Equidistant on most stuff and it computes way quicker as well.

[dlaery]

thanks, I think negative allowance sounds better than lying:nono: sorry I couldn't resist.

another toolpath you an try on it is Project Curves and select the Offset setting and set a number of offsets along with a step over distance

I found Project curves but not as a toolpath. I have version 25 - 3 axis Pro, maybe it is in a newer version