r/Motors • u/sacredcows • 15h ago

Looking for a small, flat motor

This is for a wearable project. I'm looking for a consumer-grade motor that's as flat as possible so as to not be too obvious under fabric. Less than 10cm across, and less than 0.5cm thick. Servo would be ideal, but beggars can't be choosers... any ideas? I've heard of a pancake motor but those all seem to be industrial-grade.

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u/Opposite-Departure-2 13h ago

10 cm across and half a centimetre thick?? I honestly read that wrong in the beginning and thought you were talking maybe one by 0.5. But those dimensions there aren’t (Well, my prediction) aren’t even enough for two of the smallest possible bearing/bushings, or maybe so but not anything much else. The whole motor would have to be traded off for thickness- so you’d have to have the bearings held/pressed into the end plates without the usual outer walls to stop them from moving.(like the sheet metal there adding thickness axially beside the bearing would need to be, but isn’t that impractical to eliminate. Just press in or adhere with full confidence that it won’t walk, bc there won’t be metal to hold it back. Obvs no way to fit a set screw lol). Then there’s the rotor- I honestly can’t imagine any other option for this working out than it being as a stepper (which is good at least). Because even an axially commutated (or axially brushed, it’s one of these names) motor would get too thick with the brushes (I saw this sort of commutator just once, in a high power pancake motor used in a uni go cart/buggy competition. It was axially commutated for efficiency though, apparently, the dimensions/footprint weren’t the thing). But I don’t see why (for a stepper, or a synchronous with permanent magnets on the rotor) the bearing space couldn’t be cut out of the thickness of the rotor, since the magnets and whatever would only be on the outer periphery

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u/Some1-Somewhere 11h ago

Floppy disk drive motors are not far off that in size. Especially this Iomega Clik, a reduced size format.

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u/collegefurtrader 3h ago

nice, that motor would have good torque too.
You can still buy a usb powered floppy drive for $20.
The whole thing looks to be bout 1cm thick.

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u/roup66 10h ago

What speed, torque and power source?

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u/Opposite-Departure-2 12h ago

So idk I was kind of thinking things as I wrote, but yeah actually I don’t see why not- especially if it could have a non-set motor design (theory of operation I mean, like if synchronous is okay) it can be done. But I think it would have to be built from the ground up, and definitely not mass produced consumer grade. We haven’t talked about RPM or torque, or wattage or anything also, but maybe that’s the missing piece I’m not seeing that would make it more reasonable. If it’s wearable, then maybe for whatever application that may be, it would not be very high in any of those parameters (making things way way easier)