SFM for aluminum

[Dan_AKA_ROY]

Mastercam gives me a 400 SFM for aluminum. The machinist handbook says 1000 SFM for aluminum. Why so much difference? Does MC calculate other parameters like FPT%, operation type CS%, etc. Do I calculate the starting point for my feeds and speeds using 400 SFM, 1000 SFM, or somewhere in-between?

[MichaelJ]

it depends on the tipe of cutter that you use look in the cutter catalog and look up ther feed and speed

[Chris Rizzo]

All depends on the cutter...cheap high-speed steel probably around the low end (400-600sfm), carbide around 1500+sfm.

 

Frequently you will find that spindle speeds are going to be the limiting factor in SFM condtions with modern insert and carbide tooling. I.E. A ..250" cutter running at max spindle of 7500 equals a sfm of only about 500....while the tooling mfg for their geo. and carbide recommend 1500 sfm...

hope that helps.

[Müřlıń®]

We do alui @ around 800.....

 

 

Murlin

[Dan_AKA_ROY]

Thanks for the input. Mastercam must use a conservative SFM for aluminum [other materials?]. Spindle speed, type of cutter, cutter material, etc. Nothing cut and dried but practicle knowledge thru experience. I got it. I want my machine to cut as fast and deep as possible for roughing operations. I knew 400 was too slow. I would think carbide or HSS tool bits would have different SFM when MC calculates its speeds and feeds... which reminds me of a question I forgot to ask. What's the tool material CS% for HSS and carbide?

[crazy^millman]

Well goes back to what I say about Aluminum. Balls to the Walls for roughing and your best judgement from there for anything esle.