What happens if spindle is stalled?

So I have been playing with speeds and feeds and am concerned if I slow rpm down to much. So will the spindle stall and the xy continue or is the machine smart enough to stop and alert alexa to go find the operator?

I’ve stalled mine a few times. The machine has no feedback, so it doesn’t know its stalled. The spindle will keep humming trying to run (I suppose the VFD might detect the overcurrent and shut down after a while, but not for a few seconds for sure because mine never reset before I hit the EMO button), and the motors will keep trying to drag the bit along through the wood (the nema 34’s can really plow wood with those sharp bit tips).

I have the 2 3/4" Amana bit and I keep it up at 16000 rpm, and then I find the feed and speed that it can run at w/o sounding like its loosing rpm, and then back off in speed or DOC like 10-20 percent because if you hit a high density area like epoxy or knots then you’ll need the extra margin to keep from stalling.

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I have plugged in some numbers on a few calculators and it recommends rpm and speeds that I would not be comfortable running at. I do have the OTD setting in the VFD and I have stalled it but I was right there and stopped it. Then you have to open the vfd and hit reset. It seems like it could get some feedback from the vfd, but I’m not a programer so it may be a one way street on the vfd feedback…
Initial Over-Torque Detection Parameters

3HP and 4HP Avid CNC Spindle

Parameter New Value
06-03 2
06-04 105
06-05 0.1

Mine didn’t make me reset anything on the VFD. I just hit the EMO when it stalled, then reset the EMO, rehomed and started over again.

did you set those variables in the vfd?


Angry electrons buzzing around in your motor with nowhere to go makes for a “hot time in the old town!”

I stalled the CNCDepot S30C once. It wrecked the dust manifold, twisted the motor sideways on the tramming plate and I ended up replacing two linear bearing blocks on the X carriage (may not have been related but…). It was so violent and loud that I thought I had ripped the core out of the motor.

Since I was standing there with my mouth open and a blank stare the only way it all stopped was the controller went into e-stop by itself.

Motor was fine. The Whiteside spoilboard surfacer had a chunk taken out of one blade. The X axis was wrecked. To this day I have no idea how that happened taking 1/32" off a dirty spoilboard.

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