Problem with 3D contour

[SRT Mike]

I have a part that I cut a long slot in with a ball end mill, then (to avoid another setup and operation), I cut a slot along the curve of that surface with a 1/4" ball end mill. I've attached a couple of pictures to show what I am talking about... one is the part and one is the toolpath.

Now, I know that my part has a square slot and a ball mill will give me a rounded slot - that's fine (it's just easier to reference the geometry in Mastercam with the edges).

There is 2 problems with the toolpath. First, the slot is "deeper" into the metal at the rim than it is at the bottom... I don't want that, I want it to be equal depth all the way up. I thought tip vs. center compensation would fix this but it doesn't.

The second problem is that it's sort of 'waterlining' on the toolpath... so it is only cutting at the very end of the toolpath on the first few cuts, and on the last one or two, the majority of the material gets removed. I would rather have it just follow the contour and go deeper each time.

If I turn off depth cuts, it will do just one pass following the contour, but it does it in a single cut, I would like to take 3 or 4 cuts to get to the final depth.

Any suggestions? Is a 3D contour the wrong toolpath for this operation?

Thanks

[mxer]

Sounds like you may want to use Surface Rough Parallel using the depth of cut you want to take.
May also want to look at Multi passes. I havent used 3D Contour like that but it may be what you are looking for too.

[Toonz]

Rough Flowline would work too. Just set the maximum stepdown that you want and how much you want to leave on the drive surface for the finish pass(es) and you should be good to go.