PDA

View Full Version : What bit for sheet aluminum?



sblack
12-27-2009, 12:51 PM
I am running my Joe's 2006 and cutting 0.050" 3003 aluminum. I have been using 1/8" endmills, 2 and 4 flute and having lots of adventures trying to keep the metal from welding to the cutter. Any suggestions for which type of cutter works best?

thank you

Scott

stevespo
12-27-2009, 02:36 PM
I've run into this problem as well. It's a result of moving too slowly or the spindle spinning too fast. What are your spindle RPM and feedrates?

I've had good results with 2 flute carbide endmills (.125" and .250" diameter) running them at 12-16K RPM and 90-120 IPM. This is taking light cuts, .010" to .020" per pass, and leaving .005" on the sides for a finish pass.

An occasional spray of WD-40 or cutting fluid helps with the final finishing pass, but I don't find welding to be an issue if I keep the feedrate up. If you can program a ramp cut entering the material it also helps.

There are some nice looking single flute endmills (Onsrud 63 series, etc) designed for cutting aluminum with a router, but I have not tried these.

This calculator is helpful to establishing reasonable feedrates. You'll need to plug in your chipload per tooth, and the chart can help there. One rule of thumb that has been helpful is use 2% of your tool diameter. So, 2% of .125" = .0025"/tooth, and at 12K RPM you'd want 60 IPM to maintain that load on your tool.

http://www.custompartnet.com/calculator/milling-speed-and-feed
http://www.onsrud.com/xdoc/ChipAluminum

(The 52-000 series in .125" diameter is the Onsrud 2 flute spiral upcut)

Steve