B&S Etek and clones

Sawheeler

1 µW
Joined
Oct 10, 2019
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When these came out many years back I bought 2 thru a group buy from a dealer and set them aside. Just the power I need for a tough 4 wheel mobility scooter but these hi-power pmdc motors are too loud for my liking. I have seem them now on YouTube and they have a very loud whine some what hi-pitch. Even the vids of bench tests show this whine. Golf cart motors and wheelchair motors are quiet.
Why are these B&S and Mars so loud? I need to find something else. I like PMDC so maybe 2 wheelchair motors can do the job of one Etek.
Rant over!
 
If they're high RPM they may be loud, but usually the sound you hear from a motor is the PWM from the controller as it limits current and/or controls the speed. That's often 10-20khz so it's in the high pitched annoying range.

If you used the same controller on a golfcart or other motor with a similar load at a similar speed, it'd sound about the same.

Brushed geared powerchair motors are nowhere near the power of an Etek; usually 300-400w. Some are as high as 600-700w; they're quite large and heavy, largely because of teh right-angle gearbox that converts the high RPM low torque of the motor into low RPM high torque for the wheel. You can run them higher power for short bursts, but they will overheat pretty quickly if you don't have some form of active cooling for the inside and outside. Because they're high RPM with a gearbox, they also have a whine.

There *are* brushless powerchair motors that I would guess can probably handle 2-4kw (at least for a short time; I haven't tested that yet), but they're not PMDC brushed motors, if that's what you're after. There's at least one thread (by me) on ES showing one version of one of those hubmotors. They're also big and heavy, because they're low-rpm high torque to start with, plus they have a mounting box attached to the side to bolt it to the chair, with a disc brake inside it, and a heavy rotor that is also a hub for the wheel.
 
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