To parallel the “Post up them projects” thread, here is where you can post your failures, and hopefully what you learned.
Here is me learning to cut aluminum:
What : 2mm thick 6061 (I believe) aluminum
Damage: $50 worth of end mills and about twenty hours.
Process (so far) : Fusion360->import SVG->emboss upwards->machine with “trace”
Machine specs: 800 watt water cooled Huanyang spindle on a Woodworker 1F, compressed air blowing across the end mill tip (chip clearing and cooling), 600CFM dust collector connected by 4” hose to dust boot.
- Cost: one 1/8” flat nose spiral upcut two fluted end mill and a 1/8” ball nose - snapped off my first bit because my origin was 2mm lower than it should have been. Remember I embossed upward… so on the first cut, the bit buried itself 3mm farther than it should of and snapped. The next one I got lucky because the aluminum sheet is not exactly flat and my z-probe height was high by a few mm and it wasn’t until the aluminum melted onto my bit and welded itself in place, that the second one snapped - my feed rate was too slow as the chips were not taking away enough heat and I was cutting too deep. My bit was wrong for the material and clamping was also not sufficient, which lead me to my second failure/learning:
- Cost: crashed the machine : tried a 1/4” flat nose spiral up cut two flute which tossed off extremely sharp chips and made it about half way around before it grabbed the sheet and pulled it right out from my clamps. The machine stalled out and I called it a day. I had yet to fix my origin problem being too deep.
- Cost : one more 1/8” flat nose spiral upcut two flute end mill - after fixing the clamping, zeroing my Z on the lowest part of the sheet, cutting less material on each pass and finally fixing the origin problem - my feed rate was too slow (1200mm/min) and the bit was wrong for the material. It cut about %30 of the job, got hot, welded in place and snapped.
- Cost : Success - After watching the video on this thread about cutting aluminum and getting the right end mill, a 1/4” single flute end mill made for aluminum (and costing $18) and with blue tape, glue and numerous clamps, 1500mm/min feed rate, .2mm doc, finally got it to cut.
Summary: Aluminum sheet is reactive - it gets hot, flexes, isn’t exactly flat, and bits will grind to a halt and snap. My initial success with wood, which is really forgiving with incorrect origins, depth of cut, wrong end mills and feed rates, made me overly confident.