Need Help!- 3D Contouring issues in flatter regions

[slideleft]

Hi All,
I'm trying to get REALLY fine detail on a small part I'm machining. I'm using 3D Contouring and the "Shallow" and/or "Flats" function to get good paths in the flatter areas. If you look CLOSELY at the comparison of my generated paths (blue lines over purple part) with my Verification paths (in yellow), you can see the problem I am getting- the regular step down contour eats into the flatter detail areas (am I making any sense?). I've tried several different parameters with the Shallow and Flats functions, but same problem. Anyone have ideas?

Thanks,
Jeff

MasterCamX

[ObrienDave]

This is normal when using a contour cut and the surfaces become close to parallel with the XY axis.
Think of a sphere that is sliced evenly.
As you approach the top of the ball the slices get chunky.
Shallow will help some if you really play with the settings.
It is not foolproof.
Using flats really only helps if you are using a bull nosed endmill with the detect flat areas turned on.
What you will probably have to do is run a parallel cut after the contour to clean up the chunky areas.
What I suggest is running the parallel cut perpendicular to the shallowest area.
Looks to me like a setting of 90 degrees would work for your situation.

[thebowman]

Originally Posted by ObrienDave This is normal when using a contour cut and the surfaces become close to parallel with the XY axis. Think of a sphere that is sliced evenly. As you approach the top of the ball the slices get chunky. Shallow will help some if you really play with the settings. It is not foolproof. Using flats really only helps if you are using a bull nosed endmill with the detect flat areas turned on. What you will probably have to do is run a parallel cut after the contour to clean up the chunky areas. What I suggest is running the parallel cut perpendicular to the shallowest area. Looks to me like a setting of 90 degrees would work for your situation.

Would the new Surface High Speed Finishing Horizontal Area toolpath work here?

[Matt Berube]

Originally Posted by thebowman Would the new Surface High Speed Finishing Horizontal Area toolpath work here?

Nope.

Horizontal area is for flat surfaces which are located on the X-Y plane. From what I see in the pics we are trying to machine shallow curved faces.

The best strategy for this would be to use 2 separate toolpaths. Surface Finish Contour with shallow cuts removed then finish up with Surface Finish Shallow.

The Surface Finish Shallow will give the nice even stepover that you desire in the shallow areas.

[slideleft]

Thanks everyone.
I imployed the 2 cuts strategy- Finish Contour, then Surface Finish Shallow. Works great! I forgot the Finish Shallow command existed, I'd never used it before.
And... this I'm sure has been discussed before, but, what are the practical differences between Rough Contour and Finish Contour? They seem to have the same functionality?

Merry Christmas.

Jeff