[Bearcat]

I'm running into a major problem with final cut depth in both madCAM v4.3 (in Rhino 4/5) or the latest v5 beta in Rhino 5. The Render.jpg and Render Step.jpg images show this error where the Z level finish tool, a long 0.25" diameter ball mill does not reach the flats. I originally found this while using a 15 degree taper ball mill on the same model.

Profile.jpg shows all the toolpaths and the Z Finish Depth.jpg shows the toolpath above 0.125" (tool radius). Grid spacing is 0.125". I've attached the sample 3dm (from Rhino 5).

The Roughing toolpath also shows a problem (0.25" diameter flat, and stock to leave set to 0) as it does not reach the flat on the lower right side.

I've experimented with Z finish Step Down /Angle Limit / Link Method / Toolpath Corners, Region Curves to bound the Z finish, Pencil Tracing and Re-Machining, bit diameter 0.001" smaller, model with no corner radii, etc. with no change. I've even tested the model in an older version of RhinoCAM - is OK.

Any thoughts as to how to solve this depth error?

Thanks, Ed

[JOM]

You can use planar finishing with contouring and set the angle limit to 89 degrees. This automatically makes that only the flats will be processed. This can also be used as a complement to the roughing.

/Joakim

Attachment 186086

[Bearcat]

Joakim,

Thanks for the quick response. Trying Planar as you described does reduce the anomaly, but there is still some material left in the radius - image attached. The Z finish depth in this example is 0.137" above the flat (0.012" high) and Planer is 0.017" off the part radius center (with a 0.25" diameter ball mill)

Currently changing the Z finish Step Down size changes the final depth i.e. larger step - greater distance from flat. This doesn't make sense. Is there a way to drive the Z finish to the flat?

What could I be missing?

Ed

[JOM]

Have you tried to use pencil tracing or contour re-machining? This works in most cases and also if the bottom surfaces are curved.
Attachment 186160

Another method is to control the depth by using clipping planes and that will work on your model, since the bottom surfaces are planar.

/Joakim