1" Fluted aluminum panels

[marcrunner]

Hoping for some insight with a new project. I have a couple of 1/2" thick aluminum panels(37"x12") that need 1" flutes running the short length of the panel to a depth of .33". Would probably be the easiest to just run a 1" ball nose cutter, but my spindle only accepts up to a 5/8" collet. what's my best bet to accomplish this? Would a carbide tipped core box cutter work for this application? I found a 2 flute 1" cutter with a 1/2" shank.

Thanks,
Marc

[pkirby]

Hey Marc,
I've cut aluminum one time on my Shopbot and the results were very very slow and pretty poor quality. If you have access to one, a VMC (Vertical Machining Center) is the ideal CNC for the job. I have a couple VMCs in addition to my Shopbot and I could mill probably mill an entire panel out in less than 10 minutes. If you've cut aluminum before and are familiar with it's behavior, then I'd say give it a try. If this is your first time cutting aluminum, then I recommend against it and to find a local machine shop to do it. As for the bit, I've used carbide tipped core box cutters for wood before with good success but have never tried them with aluminum. In theory is should work, but depending on the quality; the carbide tipped part might chip off. I looked on both MSC and McMaster and did not find any 1" ballnose cutters with smaller than a 0.75" diameter shank. If you have access to a lathe, you could take a HSS 1" Ballnose Endmill and turn it down to a 5/8" shank.

[8Ball]

It really depends on the alloy, but yes a carbide core bit will cut alum.
I cut a lot of 6061 alum and use carbide bits without any issues. You will need to take several passes to that depth
and set your feed and speed to cut chips or nice curls.
On my lathe, I use HSS to machine 6061 and it cuts like butter and leaves a very smooth finish.