Diy Brushless Spindle

[blackburn mark]

belleville washers
708a bearings, these are a bitch to find at the moment so a search for magneto bearings would be my second choice

I'm sure mine has about 1kg of tension (on standard skate bearings) still runs ok but doesn't get used much compared to the larger ones... if your going to hammer it to death angular contacts makes sense and would need even less tension/pre-load than the skate bearings to perform the same task

I run all my spindles at 12v (350w power supply... its never tripped)
the 100A ESC gets pretty hot but the motors are fine at that
if your cutting wood and need the extra speed you will have to stick your neck out and let us know how you get on

I'm guessing the AC bearing assembly needs to sit proud of the housing before the cover plate clamps it all in place

mine was about 1mm proud... maybe a touch less

bearings with 4 pre-load washers between them?

i think there is 8 or 10 in mine, so with only 4 you want to be approx 0.5mm proud or less, it depends on your washers

you could get really technical and do the maths but you would need to know your typical cutting force triple it, pray to the moon god and add some fairy dust :)

having at least some tension stops the bearings skidding and self destructing but if your cutting force or resonance overcomes the tension you will get a shit finish