First CAM Critique. This is SO hard!

[robpage]

Hi, I wonder if one of you CAM folks could take a look at this, my first CAM project on my new CNC.  I've watched scads of tutorials and I'm getting close but after three plywood tests of this little dice box I'm making for my son, I'm still getting incorrect depths and a bunch of random movements "cutting air" that wastes a bunch of time.  

I attached a jpg showing some of the problems I haven't been able to figure out + the F360 file.  

At first I thought the problem for the cuts being too deep was setting the "top height" to "model top."  So I tried it again setting to "stock top" and it was shallower than test two but still too deep.  Any ideas?

Thanks a mil

[jhackney1972]

As far as the depth of cut, the simulated model measures 1" deep in the main area.  This is taken from the after simulated model export.  I would suspect the error is caused by the Tool definition, in the manufacturing setup, and the actual tool position in the collet.  The program is assuming the tool protrudes out of the collet a certain distance and your tool protrudes approximately 1/8" more.  The same would be true on the smaller pocket since it is a different tool.  

[robpage]

Thanks.  I kinda understand...but actually I guess I don't.  After I change the bit I'm probing z-depth so the system knows where the top is.  Why would the tool placement in the collet matter?

But actually, I think I may have stumbled onto another possible idea what I'm doing wrong...

When I set the z-depth for the first toolpath - a facing operation, I'm zeroing at the top of the stock.  But after the facing operation I'm then zeroing z-depth to the top of the model...which is about an 1/8" lower than where the stock top was.  Could that be the issue?  And if it is, how do you z-probe subsequent toolpaths with the top of the stock removed?

EDIT: I think I just figured it out.  Do the facing operation in it's own setup then subsequent toolpaths are in a second setup with the WCS at the new model-top point.  Is that correct?

[jhackney1972]

That would do it.  This would remove the 1/8" extra depth.

[robpage]

Yeah that got it—creating a second setup and zero-ing from the new stock top.  Seems so obvious in hind sight!