Re: Quiet spindle motor?

Andrew Werby wrote:

> From: Andrew Werby <drewid@...>
>
> [I was wondering if anybody knew where I could get a 1/10 hp AC-DC
> universal motor that was nice and quiet? The Dayton spindle motor on
> my
> MaxNC 10-2 makes too much noise for home use, but I'd like to use it
> in my
> basement. Is this a function of the brushes, or the sleeve (as opposed
> to
> ball) bearings? I've had much bigger motors that ran much quieter- any
>
> suggestions? I could also use a 1/5 hp motor, for my other machine.]

My recollection from the ad photos is this is a 'sewing machine' type
motor.
Journal bearing can be much quieter than ball, although good ball
bearings
can also be fairly quiet. Brushes, themselves don't make much noise.
The shortcomings of those type motors are probably in two areas; a
minimal number of armature windings and commutator segments, and
no, or minimal balancing of the armature. I know that brush-type motors

can be made quiet, as I have some in my mill. Don't look for an AC/DC
universal motor. Instead, find a DC permanent magnet motor of modest
size and use that. You might also check out the Surplus Center
'treadmill' motors, but these may be a bit too large and heavy.
With a different (larger) pulley on the motor, a motor with lower
speed can give the same range of spindle speeds, but the slower motor
is most likely to be quieter than the sewing machine motor, which needs
to run fast to produce any torque.

Jon