Diy Brushless Spindle

[njhussey]

Basically a car radiator with fan and motor, like this:

[blackburn mark]

Basically a car radiator with fan and motor, like this:

now that is POSH!
splendid :)

[Point25]

Hello folks,

Many thanks for sharing all this info, it has inspired me to build a spindle based on a 5045 motor & ER11 8mm spindle :-) I have a couple of questions though which I hope arn't too simple !!

- The bearing arrangement is along the lines of: for the chuck/housing interface a pair of Angular Contact (AC) bearings with 4 pre-load washers between them? And for the housing/motor interface a standard roller bearing? Where would be a good place to buy the AC bearings with matching pre-load washers (either UK or eBay).... any spec available so I know what to ask for?
- I'm guessing the AC bearing assembly needs to sit proud of the housing before the cover plate clamps it all in place - how much of the bearing should be proud?
- I am looking at 24V power supplies and wondering if I need to have one large power supply to run both the NEMA17 steppers and the spindle of if I should really split this into 2 suppies with about 5A @ 24V for the steppers and 20A @ 24V for the spindle?

Thanks for any tips :-)

[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