Problem parting aluminum with a mill

[TXShelbyman]

I used my Rong Fu 45 clone to part off a piece of 1/4" aluminum angle and had issues with my end mill collecting aluminum. It is a cheap 3/16 4 flute HF end mill. It looked like the aluminum was sticking to the end mill and building up. It would eventually quit milling. I would take it out and use my machinist scale to pop the aluminum out and the end mill would cut again. It worked great facing the edge, but not parting off a section. I was running the mill @ 1180 rpm and hand feeding. Am I doing something wrong? Thanks!

 

[4GSR]

Change to a two flute end mill. Four flute end mills are not made for milling aluminum. Use a cutting fluid, too. That should help keep the aluminum from building up on the flutes of an end mill.

 

[kd4gij]

WD40 will be your friend for this

 

[Tony Wells]

Lube and speed things up. That's a little slow for a 3/16" end mill. But the main thing to prevent or lessen chip welding is lube. If you have to do it dry, keep a constant air jet in the cut to keep it clear of chips. That will help a great deal.

 

[celtic1522]

CRC 556 or WD 40 is good, anything with Teflon in it works well. Cutter must be sharp and keep feeding the cutter into the material. Too much speed is as bad as too little I find, both cause addhesion to the cutter.

 

[T Bredehoft]

I've found that rubbing alcohol works well. Little if any adhesion and zero residue. But only on aluminum.

 

[TXShelbyman]

Thanks! I will try some lube and see what happens.

 

[Wreck™Wreck]

Change to a two flute end mill. Four flute end mills are not made for milling aluminum. Use a cutting fluid, too. That should help keep the aluminum from building up on the flutes of an end mill.

A 4 flute endmill will work fine in aluminum it is merely slower, the number of flutes is unrelated to the built up edge problem, only coolant or cutting fluid will solve that, coatings, climb milling and speed will also help. I suspect that the OP may be working with 6063 alloy readily available in hardware stores, this material will glue itself to anything without coolant, very difficult to machine.

 

[TXShelbyman]

You suspect right Wreck. It was angle purchased at the local hardware store. My little mill tops out at 1970 rpm and that would be giving her all she's got. I will go up from 1180 and add some cutting fluid. Thanks again!

 

[tweinke]

Same experience here with hardware store aluminum. Seems to be a toss up too, some cuts nice some terrible. WD40 works about as well as anything but speeds and feeds appear to be a narrow window between works and don't.