Cutting Aluminum Composite Sheets

Advice on bit choice and techniques for machining aluminum composite panels on CNC equipment. February 17, 2012

Question
Does anyone have a specific bit recommendation for cutting aluminum composite sheets? I have had some jobs where I have cut Max Metal alumacore board. I used an Onsrud single upspiral but had issues with the top edge of material burring up upon the entry move (regardless of what angle), and sometimes even the bottom face edge burring. I'm doing a finishing pass on everything now. Anyone have a specific bit number that works well for them?

Forum Responses
(CNC Forum)
From contributor D:
I use an Onsrud 65 series O flute with no problem.



From contributor F:
I use a 1/4" O flute with great results. 180 ipm 100 ipm plunge 18000 rpm.


From the original questioner:
Are you using any coolant?


From contributor F:
Can't use coolant when you have an MDF bed.


From the original questioner:
So no air coolant or anything, just single cut at those speeds? I'll give it a shot.


From contributor F:
I did actually buy a Vortex Tube for air cooling, but don't have a big enough compressor to keep it running. I realized I didn't take the time to research this specific material, so my comments may be misleading. The material I have worked with has a thin layer of aluminum on both faces, pre-painted black, with an inner layer of abs or hdpe plastic, not corrugated. Overall thickness is .125. Hope I didn't cause any confusion.


From the original questioner:
That's the same stuff. The max metal I have cut is white with black core. Itís very thin aluminum faces I just have had trouble getting clean edge.


From the original questioner:
I cut a bunch today with a new O flute from MSCdirect. I ran it at 180ipm 18,000 and it cut much better. I think I was running it too slowly before. I'm cutting pretty small parts and I really wish the masking film on the Max Metal was thicker. Itís near impossible to not cut through it.


From contributor F:
We use a double sided masking tape to hold down small parts in addition to the vacuum. We get it from Bron tapes, and they cut it 1/2" wide for us. Itís super strong stuff and sticks fine to the MDF spoilboard.


From contributor G:
We have been cutting a bunch of the reynobond. I use a 3/8" O flute from Onsrud. Material thickness is 4mm. Spindle speed is 16k and feed rate is 400 ipm. After cutting a whole sheet the tool is only warm to the touch with the shavings containing the heat. The cut is nice and clean and no burrs.