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Oct 14, 2002, 09:51 AM
Registered User
hrvojekl's Avatar

Smallest brushless in the World

Faulhaber micro brushless with 47:1 gearbox
dia. 1.9 mm
lenght 5.5 mm
no load rpm. 100000
60 mW at 0.5 V

what to do with that!?
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Oct 14, 2002, 10:18 AM
Living Room Aviator
drliu's Avatar
I wonder what the efficiency of this tiny motor is. Usually the efficiency of pager motors drops precipitously as they get smaller, though of course this motor is very different in design from the pager motors.

It also uses quite a bit more current compared with most 4 mm pager motors (though presumably this enables it to put out some healthy power).

The 4 mm motors I currently use to fly only weigh about 0.7 g each, so one can anticipate this motor to weigh less than 0.4 g. The gearbox may weigh less than our current gearboxes as well (typically 0.5 to 1 g ea).

Is it readily available from some retailer? If so, please post details!

Oct 14, 2002, 10:27 AM
Living Room Aviator
drliu's Avatar
Judging from the MicroMo website, this motor appears to be a AC three-phase motor?

Oct 14, 2002, 11:15 AM
in persuit of low wing loading
Gordon Johnson's Avatar

Contact the US dividion of Faulhaber and they may be able to help you. Generally they stock the motors in limited quantities for firms wanting to do development work using their motors. Prices are usually fairly high. For example, one of the US offices of Maxon is near us in Rhode Island. We can buy a motor/gearbox from them in quantity one that is identical to the Astro Firefly, except that it will cost us more than what we can get it for direct from Astro Flight. I think a question would be what ESC you use to control this thing, and what it would weigh.

Oct 14, 2002, 11:30 AM
high-speed freak
opualuan's Avatar
I have one.

it's $600 in single quantities, $100 in quantities of 100+

I've done simulations and it doesn't seem to do all that well.

0.5v nominal, it's pretty useless for us (lithium 3.6v is our ideal power source)

cool, but...

smoovy has some small motors for a lot cheaper.

I don't think there exists a battery light enough for this motor to haul around...
Oct 14, 2002, 01:20 PM
Registered User
Steve McBride's Avatar
I would suspect efficency to be in the sub 25% category compared to other similar motors, although manufacturers claims can vary.

Interestingly, had nothing about it on their site that I could find......

Steve McBride
Oct 14, 2002, 03:02 PM
Registered User
hrvojekl's Avatar
Steve, go to to Produkte, then to Micro-Antriebssysteme, there is tech
info in pdf
Oct 14, 2002, 03:03 PM
Registered User
flytowner's Avatar
Take a business card and cut it into a zagi shape. Make a micro prop for it and CA it to the business card with a watch battery and walla... Flying business card! Fly it around in your local telephone booth!
Oct 14, 2002, 04:51 PM
Living Room Aviator
drliu's Avatar
Has anyone run tests on the 5 mm and 3 mm smoovy motors? I saw those a while ago when I was settling on the final configuration of the Wisp but discounted the 3 mm motor/gearbox for being too weak (45 ohm) and the 5 mm motor/gearbox for being too heavy. It might be worth taking another look at the 3 mm motor as we continue to build smaller and lighter.

Oct 14, 2002, 05:04 PM
Registered User
hrvojekl's Avatar
Look at maybe few years from now we will fly on this
instead today batteries.
Oct 14, 2002, 05:11 PM
Registered User
Steve McBride's Avatar
I've been in contact with the US distributor of the smoovy motors and the latest was that they are still undergoing changes. I have not talked to them in a few weeks though. It's the listed power output that scares me - 160ma short term for the 5mm and 57ma for the 3mm. I wonder how much one could puch these little guys though?

Steve McBride
Oct 14, 2002, 05:21 PM
Registered User
flytowner's Avatar
WOW! Do you realize if we started using the Octane power source we would technically be "slimers"!
Oct 15, 2002, 07:07 PM
Registered User
Keennon's Avatar

1.9mm brushless

I have run tests on the 1.9mm Micro Mo motor as well as the 3mm, 5mm Smoovy brushless and the Namiki 4mm brushless motors.

The 1.9mm motor was supplied to me with a 3 stage planetary and a dedicated controller demo box. It ran for a while and then died. I think a gear tooth broke or something, it was dissappointing.

The 1.9mm motor I had required like 0.5 volts at 100mA which is an odd combination of voltage and current if you want to run it efficiently. It would really need a step down power coverter, and then use 6 mosfets to switch the 100mA, so it's not so desireable.

On the other hand, the Smoovy 3mm motor can be operated at a couple volts and 20mA which is handy if using the outputs of a microcontroller to drive the motor directly. The 3mm Smoovy motors are running in the hundreds of dollars apiece without gears, gears are more expensive.

The planetary gears on the Smoovies are also delicate and I have accidentally busted about 80% of the Smoovy gearmotors I have handled over the last 5 years, and I was trying to be careful. Problem is all the gears are the same tooth pitch and thickness, so at the output stage, the teeth are very weak. But they are wonderful little gearmotors and will operate reliably if you are careful with your installation and handling.

The 4mm Namiki brushless is hundreds of dollars apiece with gears, and appears to be good quality. Did not test the gears.

If only there was a mass market for micro brushless motors like for pagers, the prices would be only a few dollars apiece, because they are simpler to make than current brush DC motors, but use the same basic materials. It all comes down to production quantity.

Just my thoughts.

-Matt Keennon
Oct 15, 2002, 07:49 PM
Sticky Shepherd
Graham Stabler's Avatar
perhaps tiny disk based music formats might make this kind of motor available, in the mean time we could wind our own.

I'm not joking but probably should be.


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