Help me understand Profile of a Surface

[Jeff]

Something else to consider is the size of the probe styli they are using. Say for example you have a 64 surface finish callout and you held it to a 32. Now if Thee CMM guy is using a 2mm stylus and you hit a peak and a valley, that could easily throw out out 5mm in a worse case scenario.

I worked on a part one time that had a .02mm profile tolerance and the surface finish callnout was a 32. The CMM inspector was using a .5mm ruby and refused to change it. In order for the part to CMM good I had to get the finish down to between 6 and 8. Even then I was using 90% of the tolerance band. Sucked. That inspector was garbage.

Not really any peaks or valleys, it's a nice smooth wall surface, but I do get what you mean.
These parts are WIDE open +/-.03 on linear dimensions and no finish callout because they end up getting powder coated.

[Tim Johnson]

7075 aluminum has up to 2% copper. If the material is being cut hard and depending on the shape the copper can heat up and warp the material.

[Jeff]

7075 aluminum has up to 2% copper. If the material is being cut hard and depending on the shape the copper can heat up and warp the material.

We're pushing 260% spindle load whenever the 2" Mitsubishi AXD4000 shoulder mill is being used, it roughs the outer form and the inner pockets 2" deep. But TSC is being used.
I fucking love that cutter.

[Jeff]

260% spindle load means it's hauling.
Ima going with some stress relaxation in the days after the part is finished....

Well to be fair, it's only a 27hp spindle in a Hyundai-Wia mill. 7600rpm, 2" full diameter cut 3fl, ramping .150" deep in a pocket at 265ipm. That's the rpm range I found to have the best torque and hp ratio for that cut. It's hauilin ass to the extent of that machine's capabilities.
If that were an Okuma that has true 30hp, the load would be much much lower.

[JakeL]

We're pushing 260% spindle load whenever the 2" Mitsubishi AXD4000 shoulder mill is being used, it roughs the outer form and the inner pockets 2" deep. But TSC is being used.
I fucking love that cutter.

That cutter is an animal. It's our go to for aluminum.

[gcode]

If that were an Okuma that has true 30hp, the load would be much much lower.

No.. the IPM would be much higher