Re: Quiet Spindle motor
Posted by
Andrew Werby
on 2000-02-24 04:58:24 UTC
I wrote:
Subject: Re: Quiet spindle motor?
I've got a sherline with the older AC motor, that is also on the noisy
side. Contributions seem to come from the fan, brushes, relatively low
switching rate of the control, the fairly high RPM you find on these
small machines, and the fact that they vibrate a lot more for a given
imbalance than a heavy cast iron machine would.
Could you just put it in a foam-lined plywood & plexiglass box with
isolation feet (machine-box and maybe box-table)?
[I've had the same thought- no doubt this would help, although I'd have to
balance the anti-noise effect of the foam and plywood with the restriction
of visibility from the plex. I was planning to do this anyway. Isolating
the machine from the structure would also help. But I'd like to start with
a quieter motor, if possible- then I might be able to run it at night.]
Craig C Chamberlin <ccc@...>
You can buy the current Sherline motor and control box separately...Price
is $US150-175. It is very quiet.
Craig
[I checked on that- I even got the Sherline folks to hold their motor up to
the phone and turn it on- it was quieter than mine. Unfortunately, the
Sherline DC motor is considerably larger and heavier than the one I'm
replacing, and I'm afraid it will weigh down the z-axis unduly. It is also
considerably slower, running at ~3000 rpm instead of 10,000 rpm in the
motor I'm replacing. I suppose I could change the pulley system to be 1/1
instead of the 1/3 reduction it now uses, but rigging a counterweight
system would be difficult. And what with tax and shipping, the thing is up
over $200 already.]
Jon Elson <jmelson@...> wrote:
My recollection from the ad photos is this is a 'sewing machine' type
motor.
[Right- they are easy to slow down with electronic speed controllers.]
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.
[Is this what makes them noisy?]
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
[Thanks, Jon, Chris, and Craig. This gets me somewhat farther along. I
suppose I can find a DC motor the right size and change my pulleys (if I
can find the right ones for those skinny little belts) - but what kind of
transformer would I need to run it on a more or less continuous basis? How
much should I expect to spend? I'd like to switch my other one (the 1/5 hp)
over as well, but the speed control for this one is controlled by
software, so that if I wish to preserve that feature I'd have to replace
like with like.]
Andrew Werby
http://www.computersculpture.com
Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com
Subject: Re: Quiet spindle motor?
> [I was wondering if anybody knew where I could get a 1/10 hp AC-DCChris Stratton stratton@... wrote:
> 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.]
>
I've got a sherline with the older AC motor, that is also on the noisy
side. Contributions seem to come from the fan, brushes, relatively low
switching rate of the control, the fairly high RPM you find on these
small machines, and the fact that they vibrate a lot more for a given
imbalance than a heavy cast iron machine would.
Could you just put it in a foam-lined plywood & plexiglass box with
isolation feet (machine-box and maybe box-table)?
[I've had the same thought- no doubt this would help, although I'd have to
balance the anti-noise effect of the foam and plywood with the restriction
of visibility from the plex. I was planning to do this anyway. Isolating
the machine from the structure would also help. But I'd like to start with
a quieter motor, if possible- then I might be able to run it at night.]
Craig C Chamberlin <ccc@...>
You can buy the current Sherline motor and control box separately...Price
is $US150-175. It is very quiet.
Craig
[I checked on that- I even got the Sherline folks to hold their motor up to
the phone and turn it on- it was quieter than mine. Unfortunately, the
Sherline DC motor is considerably larger and heavier than the one I'm
replacing, and I'm afraid it will weigh down the z-axis unduly. It is also
considerably slower, running at ~3000 rpm instead of 10,000 rpm in the
motor I'm replacing. I suppose I could change the pulley system to be 1/1
instead of the 1/3 reduction it now uses, but rigging a counterweight
system would be difficult. And what with tax and shipping, the thing is up
over $200 already.]
Jon Elson <jmelson@...> wrote:
My recollection from the ad photos is this is a 'sewing machine' type
motor.
[Right- they are easy to slow down with electronic speed controllers.]
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.
[Is this what makes them noisy?]
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
[Thanks, Jon, Chris, and Craig. This gets me somewhat farther along. I
suppose I can find a DC motor the right size and change my pulleys (if I
can find the right ones for those skinny little belts) - but what kind of
transformer would I need to run it on a more or less continuous basis? How
much should I expect to spend? I'd like to switch my other one (the 1/5 hp)
over as well, but the speed control for this one is controlled by
software, so that if I wish to preserve that feature I'd have to replace
like with like.]
Andrew Werby
http://www.computersculpture.com
Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com