Rotary Contour leaves a triangular floor finish on cylindrical parts - Using a 5 axis as a lathe

[15mre]

Machine: Mikron Mill E 500 U with TNC 640 Heidenhain control (Similar to a DMG DMU 50 for reference)

For the general profile of the part I can use a small ball endmill and Rotary Parallel spinning the C axis slowly to cover the part, however this leaves some fillets next to flanges. To remove the fillets I would like to use the Rotary Parallel toolpath but I have an issue where the simulation differs from the machined part. Instead of the floor being flat, where the center of the tool cuts is several thousands higher and this leaves a triangular surface finish.

I compiled a PDF with some photos. Any input would be awesome. 

[a.laasW8M6T · Accepted solution]

Hi

The Triangular shape is caused by the tool geometry, even though the tool is "Center Cutting" it actually has a Dish ground into the end of the tool.

Picture is an exaggerated example:

Basically all flat endmills are ground like this.

To get a better approximation(it will never be perfect) of the cylindrical geometry with the Rotary toolpath you need a tool small enough that you can step it over in small increments to "Remove" the material caused by the dish.

[15mre]

Shoot, you're totally right! Hadn't thought of that possibility. Thank you!