- Joined
- Aug 12, 2013
- Messages
- 858
The photos above are 770rpm and a .005" feed rate, I've tried them all and nothing helps.
These next photos are the same piece of aluminum with half of it turned at 475rpm with the slowest feed rate of .0027".
WAY WAY too slow on the spindle speed. Aluminum likes speed.
RPM = 4*sfm/D = 4*500/ (5/8") = 3200 rpm!
sfm for Aluminum with carbide 500-1000 (1/4 that for HSS)
If you don't like doing math, then get HSMAdvisor or G-Wizard.
The above is really for using with coolant, but I would be cutting that 5/8" aluminum rod at a minimum of 2000 rpm. Aluminum likes high speed, and it doesn't like low speed.
What about DOC? Start with at least a 0.030" DOC, and you will get a mirror finish... except when you run the carriage back to the right, you will get a spiral on it. Then take a spring pass.
Try a feed of 0.004ipr (too small a feed rate can be just as bad as too high a feed rate.... you end up rubbing instead of cutting, and that destroys your surface finish).