Our Fall 2015 Sine Plate Project

[ParisDakar]

This week we faced the other side of the plate with the flycutter. Set the tool to cut about a 3.5" diameter circle, so we could face the full 6" plate width in two passes. We cut .003 to .004" with each pass. Only took 3 cuts or about .010" to completely surface this side. 1250 rpm produced the best finish. The cutting tool is carbide tipped HSS. I ground a radius on the point of the tool this week, maybe 3/32". Finish is better than last time when it had a sharper point. Tool rake angle is 0. Feed rate was about 3" per minute for a chip load of a little more than .002".

The mill is definitely out of alignment a bit. When I upload the pics, you can see the difference between a L to R pass and a R to L pass. The tool cuts lower on the left. So on the the L to R pass, the trailing edge of the tool drags the surface producing a fine, sandy texture. Best cut in this case is in the R to L direction, where only the leading edge is cutting.