Spindle stall on a rush job in Nashville last month

I was cutting a batch of aluminum brackets on a Friday afternoon when the spindle just bogged down and stalled. Turns out my feed rate was way too aggressive for that 3/8 end mill, and I hadn't double checked the speeds. Shop foreman walked over and asked if I heard the motor struggling, but I had my earplugs in. Has anyone else had a spindle stall throw off their whole production run?

2 comments

2 Comments

danielr9428d agoTop Commenter

And @the_ryan is right about chip load, but the thing nobody's mentioned is how much runout can make a stall worse. If your collet has even a few tenths of runout, that endmill is cutting unevenly and loading up way before you'd expect. I caught a spindle stall last month on some 7075 and found out after that my holder had 0.0005 runout. Switched to a shrink fit holder and the difference was night and day. The material you're cutting matters too, 6061 lets you push harder but 7075 or cast aluminum will stall faster if you're not paying attention.

the_ryan29d ago

Man, that SUCKS. I've been there with a 1/4" end mill on 6061 thinking I could push it like a 1/2" tool. That bogged down feeling is the WORST. It throws your whole setup out of whack and you lose half a day redoing offsets and checking for wallowed out collets. You gotta run those small end mills with a lighter chip load or they'll just give up on you.