Alt-BEAM Archive
Message #09440
To: beam@sgiblab.sgi.com
From: Scott Burns s-burns@uiuc.edu
Date: Fri, 21 Jan 2000 09:17:05 -0600
Subject: [alt-beam] Re: Incredible gear motors
I just tested the two Lego micromotors I received ($11 in the US each,
including shipping). At 2.5v they draw 4mA free running (about 7 RPM) and
22 mA stalled with my fingers. At 5v they draw 5 mA free running (about 15
rpm) and 50 mA stalled.
Order them at 800-453-4652, part number 5119.
Scott
At 10:05 PM 1/20/00 -0700, you wrote:
>One of my friends had two of these motors at the robotix club meeting at my
>school. They are incredable motors... Here's an example of how efficient
>they are:
>
>wire two of the motors together. Spin one, and the other will spin (from
>the generated electricity) at the same speed! OK, it was probably slightly
>slower, but the difference in speed is not visible to the eye.
>
>Spin them, and the continue spinning for a while. Short the imputs, and it
>immediately brakes.
>
>These are incredible motors.
>
>Does someone want to crack open a brick and see who makes the motors? Maybe
>we can buy the motors without paying for the brick and the markup that LEGO
>certainly puts on!
>
>
>-Nathaniel Martin
>nat@lumiere.net
>
>
> >Do these specifications sound interesting?
> >
> >Gear motor:
> >
> >1cm x 1cm x 1.3cm
> >2-9v
> >8mA draw!!! (no load)
> >32 rpm
> >surprisingly tourquy
> >15 grams - VERY light
> >
> >They could even be smaller, because they are surrounded by a plastic case
> >that i have not cracked open yet. The source? LEGO. These are the micro
> >gearmotors for the mindstorms sets. I believe the cost is $17 CAD each. A
> >friend of mine bought $4000 worth of mindstorms gear and was showing me some
> >of his creations. When i saw these motors i practically freaked.
> >Absolutely perfect for heads, and 2DOF heads - because they are so light.
> >With their low current draw, micro walkers are a possibility. I'm going to
> >order some and try them out. Never seen gearmotor specs so promising.
> >
> >You can order them direct from LEGO. www.lego.com
> >
> >Nowhere near as powerful as a BG mirco, but so much smaller, lighter, and
> >less draw.
> >
> >I think a micro walker would be a very interesting project....
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