DW660 with variable speed controller, running at ~ 18k rpm. 2mm depth of pass with a 10mm/s feedrate. MPNC has been working great cutting MDF and pine. I re-surfaced spoil board and verified that the overall squareness of the machine.
Do you notice anything else besides the bit breaking?
Those bits are quite pricey. But I have not broken a bit with 18mm BB and gone closer to 6mm DOC and 10mm/s. I use the ones from Ryan’s shop. I have dulled the bits. IIRC, the only time I broke a bit was with a deep straight plunge.
You should have no problem with those numbers. I would start looking for a missing bolt or something, loose pulley. Is it always plunging or anything when it breaks?
Both bits broke on X-Y move, not plunging. I was cutting the back (for MP3DP), all 8 holes were drilled perfectly, they broke during outside tool path (not at the point where depth was increasing). There seemed to be some excessive x-y wobble if I tried to wiggled the middle assembly. So I decided it was best to disassemble and verify everything. The only bolts loose were the tension bolts (as they should be). I suspect everything will be fine when I get it back together.
The MPCNC is in the garage … there is no telling if a basketball, lacrosse stick or something else decided to land on it. The kids don’t seem to respect the machine the way I do
I agree the Freud’s are pricy … they stock them at local Woodcraft. I just ordered bits from Ryan’s shop, certainly not sure why I hadn’t.