Cutting Holes in Aluminum

[bill_l]

Can anyone suggest what type of carbide bit could be used to profile cut holes in aluminum stock that is .05" thick. It would be the type of material that would be used for the control panel of a guitar amplifier or stereo etc. The holes would be for the control pots and knobs.

Also, any suggestions on feed / speed would be helpful.

[mrdovey]

I've used 2 and 3-flute carbide end mills (they look remarkably like spiral up-cut router bits, but cost less) on thicker aluminum.

I've been running 0.125 in/sec at 4000 RPM with 1/4" 3-flute bits.

This past week I tried out a Cincinnati-Milicron(sp?) CNC and used 22 in/min at 6200 RPM with a 2-flute 1/2" bit. It couldn't have been smoother cut.

Use the largest bit you can to minimize tool chatter marks.

[myxpykalix]

Hi Bill,
Call Fred at Centurion tools at:
Phone 540.967.5402
http://www.centuriontools.com/
They make some great bits at good prices and can tell you exactly what you need. A lot of what they make are bits for metal cutting and i've watched them design and manufacture bits for the automotive industry that are pretty slick so they can definitely help you.

[Brady Watson]

A single flute-O tool (Onsrud or Belin) is the weapon of choice for this thickness of material. Try 13,000 - 15,000 RPM @ 1 to 1.5 IPS. Hold down is important - vacuum being the best, screws & clamps being the worst. Tape will work, but will gum up edge, cutter and possibly warp/bend material when removing from table. If the edge quality is better on the scrap than the finished part, then reverse direction (climb mill). Try to ramp into the cut instead of plunging straight down into it if you can.

-B

[bill_l]

Thanks guys ... I'll be off to the races shortly.

Bill

[jim_ludi]

Bill, you might be interested in what Keith Vonderhulls, at buildyourownclone.com, is doing with his Bot to machine holes for the stomp box kits that they build. You can see a video of his bot at work at: http://www.youtube.com/watch?v=UoSVAeMCoY4, or do a google video search for buildyourownclone. The boxes might be thicker than your face plates but the idea is the same.

It would be interesting to hear how Keith's spindle is holding up to all that plunge cutting.

Jim

[bill_l]

Thanks Jim.