I'm making 10 flat plates (approx 3.5" x 6.5") with a curved outline out of 0.063" thick aluminum sheet. This plate fits inside another assembly and I need to hold a tolerance of +/- 0.010". For my prototype I cut out the plate with a 1/8" flat endmill in 3 passes of 0.021" on my Taig CNC mill. If my production rate increases I will look into sending the work out for water jet, but in the meantime I'll be using the Taig mill (if you don't know the Taig mill, it's a small hobby mill with not much HP).
I'm wondering if a faster cutter is available - perhaps a roto-zip cutter? I'd like to cut the plates in one pass if possible (don't know if the Taig motor can handle that). I'd be OK doing minor clean- up of the edges with emery cloth if it cuts fast.
Regards, Ed Ferguson
Get a 1/8" solid catbide end mill. It can do .062" aluminum if you can keep the chips from piling up. You may want an air blast to clear the chips.
It can defintely cut that thickness. I had an accident with one, and it went plowing through 1/8" aluminum at 40 IPM without breaking! You can try 2-flute, but I often use a 4-flute as it gives twice as many cutting edges per rev. You'd probably want lots of speed on the spindle for that size cutter.
Any through holes in the part that could be used as jig pin holes?
Ten thou sounds well within the realms of the possible for a router table with a decent carbide bit with a pilot bearing on it. Make a master from 1/4" plate, then run the pilot bearing on that while the cutter cleans off the sheet stock.
I suspect that a little parafin canning wax and a heat gun could serve as a replacement fot the pins, though it would slow down the production rate. Still way faster than the Taig, I'd bet.
63 thou stock would be dead easy for a wood router.
Cheers Trevor Jones
Good input. The part has a 3" dia hole and I've pre-drilled two fixture holes inside the large hole for securing to my mill plate. I have a router table and router - I may give that a try with a carbide cutter. My router certainly has more HP than my Taig spindle.
Regards, Ed Ferguson
Why waterjet? Lasers are faster and cheaper for that kind of work, and you'll get more parts per sheet than with milling.
Check out where I work:
If you can attach an AutoCad file, or FAX a print, we can quote it.
For waterjet cutting speeds, you may want to download the abrasivejet feed rate calculator at:
0.010" tolarance is super easy to get. For such thin material, you might even consider cutting a stack of parts in one pass. There is a list of waterjet job-shops at the above link also.
As far as being the "fastest way", I can't say. This material is so thin that lots of methods could cut it quickly. I would consider lasers, waterjet (abrasivejet), and stamping. Which works best will depend on you needs and quantities.
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