Experience with brushless air-cooled spindles?

mcdanlj
Sun, 04 Aug 2019 17:54:58 +0000
CNC Routers

I’m looking at spindles. In the short term, I’m hoping that the replacement power supply I am buying for my air-cooled brushed DC spindle gets me going, but in the longer run I probably want a better spindle. This router is for cutting wood and occasional plastic; rarely aluminum (for new plates, such as if I cut-it-forward) so I don’t see a reason to add the weight for water-cooled.

I see some spindles with only two wires advertised as brushless, which I assume means that they have an ESC built into the motor. Are these intended to be a drop-in replacement for brushed spindles, without the brushes? Do they have downsides relative to brushed spindles they replace? Since they are essentially three-phase AC motors, do they tend to have smoother torque and a better cut?

I see some brushless spindles with only three wires and no hall sensor. Is back-EMF sensing good enough for normal CNC router usage, so no real need for hall sensor if I’m cutting wood and plastic? It has to be synchronous to work at all, so my guess is that for this use hall sensor is unnecessary.

I see some brushless spindles with integrated hall sensors that use five sense wires as well as three power wires to connect to the controller. How sensitive to noise are these sense wires typically?

11 posts - 3 participants