Originally Posted by
zaebis
Folks,
Those who have used lots of so called aluminum endmills (35 heliz + peculiar tip) vs traditional 30 helix of the same size. Is there really a difference for aluminum applications?
I'm pretty fond of the Accupro (MSC) 3 flute 35deg helix ZrN coated endmills in aluminum but have recently started using the same spec Titan end mills with the same results. These aluminum specific end mills are worth the price over more conventional 2 flute end mills as they allow you to remove metal much more efficiently, meaning better profits. I have a job on one of the mills at work right now that runs a 3/4in .06R bull mill at 9600 rpm; 415ipm with a .245 DOC and a .450 step over. 40 taper 15K spindle using the high speed machining control parameters with a constant spindle load of 93% with a couple of entries into "heavy" corners that spike up almost to 130% for 5 or 6 seconds. If this was a conventional end mill I'd be running around 100-130ipm. This mill is finishing some features of the part feeding at 215ipm leaving better than a 125 finish which is within spec. If the surface roughness call out was tighter I'd run it at about 8600 rpm feeding @ 93ipm on the finish passes to hold a 63 roughness walls and floors. Tool life is good, roughing 6 parts with a cycle time for that tool of 35 minutes. With machine time @ $75US we are more than paying for the extra end mills and making more money per part than a more conventional end mill would allow. The only draw back was the operator kept calling from the floor on the first part to tell me I was running the tool entirely to fast. I finally took him a roll of toilet paper and told him 3 squares only per part. After that he cut one complete part and saw the condition of the tool. He was then bragging to the other operators about what he was doing on his machine. I am cutting 7075-6 but proofed this in 6061-6 plate we cut on the waterjet. In 6061 the spindle loading was slightly lower and the chip a little tighter but otherwise the same. The difference for me is profits for the company and moving more part numbers across my machine table.
Suppose you were an idiot and suppose you were a member of Congress. But I repeat myself.
Mark Twain