Need Help!- Machining Roto Molds

[lkenney]

I am making my first of what I hope will be many facemask molds. The product is a plastic air filled cushion/ I am cutting the mold from 6061 T6 using MasterCam X4 3D from SolidWorks models. This mask is shaped kind of like the seal on a CPAP or paint mask It is about 0.700" wide at the top and about an 1.25" deep taper is 1 1/2 degree on each wall bottom is 0.38 wide.

The first two molds that I finished are not bad but can be better. I rough mill with a 3/8" Bull Mill with a 0.0313 radius and then finish mill with a 3/8" ball mill both are carbide 3 flute. The mill is a VF-0 7500 RPM machine I have some vertical lines that are evenlly spaced around the mold about 0.100" inch apart giving the walls a very small corrigated look. I can polish them out pretty quickly but would of course prefer not to have to do that.

I am open for any suggestions, thank you in advance.

Lowell

[jeffrey001]

You could post a picture and type of tool path you used for your mold, this would help others identify your problem.

Jeff

[SORCHEROR]

in toolpaths check to see what your step over is and your tolerance is,thats where the problem is,i bet you have .100 step over and or a large tolerance setting