3D contour - compensation

[thingmaker]

Hello,

I have a 3D contour op(2 planes connected with a curve)where I am (finishing the vertical corners) running along the border contour in 2D for a bit and then climbing up on the Z+ hyperbolic curve meeting and blending into the next plane.

The cutter left comp is working in my backplot, but when I Front view it, the spherical tip appears to overcut into my curve on the way up on one side and on the way down on the other side. I tried tip/center comp...no difference or noticeable improvement.

I am surface machining the curved section only and wanted to blend the bottom corners of both pockets (at 2 levels) by simply letting a sperical cutter run along the contour boundaries.

Isn't this a 3D contour operation (my preference? If so, how can I prevent my sperical endmill from overcutting when it moves in Z+/-? Or, should I just surface both planes(pockets)and choose an appropriate finishing surface machining routine?

I appreciate any thoughts on using 3D contour option sucessfully. I am home Sunday trying to prepare this for Monday. Thanks people.

(Xmr2)

[terry5357]

I ran into the same problem. I was told by Bryan Johnson (MLC) that your curve needs to be projected onto a surfaceso that the tool will check behind as well as in front. I had to create a couple of surfaces and then project the contour on to the surface and then cut the projected contour as a 3d contour. worked perfectly. I want to say that I was using Ver. 9 at the time so MCX may have a shorter way to get to where you want to be

HTH

[JDowe]

If you xform offset the contour in the +z direction by the amount of the cutter radius

and program to the center of a ball endmill

I think you will get the result you need

[thingmaker]

Excellent JD...that makes sense and it works! Terry, I projected the Z-/+ curve onto a Y surface plane, still overcutting is visible in my verification.

Thank you both.

[Bryan Johnson]

instead of projecting the curve and then using 3D contour. Try Surface Finish Project, and project the 2d contour operation.

[Mcam Nut]

Thingmaker, JD's sugestion will work in alot of situations, but project toolpath imo is the better method, because you are actully folowing the surface rather then just lifting to tool off the surface. however I personally dont use a 3d contour for a projected toolpath, I usually will project the 3d geometry into 2d, and do a 2d contour, then project that toolpath to the surface.