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This is interesting information, thanks TJ. I must say that I got the visual
impression that the buggy motors seemed to have more than a mere 2 - 3 times
more shaft power output than the gear motors.
The little piece of data which would add greatly to your 2 - 3 times figure
would be the current consumption. I have a nasty feeling that the Technic
gear motor has set the gold standard for electric to mechanical power
conversion efficiency. If the buggy motors make 3 times the torque converted
to the same rpm, but at the expense of 10 times the power consumption (which
I have a feeling is the case) then for battery operated applications like
99% of Technic/Mindstorms creations, they are not quite such a hot prospect.
JB
In lugnet.technic, Thomas Avery writes:
> Last night I performed a few quick tests on the 5292 motors (the new motors
> from the 8475 Race Buggy set:
> http://www.bricklink.com/catalogItem.asp?P=5292) to compare them to the
> standard geared 9V motor
> (http://guide.lugnet.com/partsref/search.cgi?q=71427c01).
>
> In summary, the 5292 motor (when geared down to match RPM of 71427) has
> about 2.33 times more torque (when stalled). I powered the motors with a 9V
> train controller, the dial being rotated to maximum output.
>
> The test set up was simple. I tested the 5292 in several arrangements, and
> also tested the 71427 motor for comparison. The test involved powering a
> winch that lifted a variable weight. I increased weight until the motor
> could just barely lift it. This test and winch set up may not provide the
> most precise answers, but will hopefully give us a fair comparison of the
> motors (which was my goal).
>
> The test set-up and maximum torque results are presented below:
>
> • 5292 motor, 1:1 ratio[1], 1200 rpm output[2], TORQUE = 0.40 lb·in (4.6 N·cm)
> • 5292 motor, 1:3 ratio[1, 3], 1200 rpm output[2], TORQUE = 1.09 lb·in (12.4
> N·cm)
> • 5292 motor, 1:1 ratio[1], 1700 rpm output[2], TORQUE = 0.34 lb·in (3.8 N·cm)
> • 71427 motor, 1:1 ratio[1], TORQUE = 0.48 lb·in (5.5 N·cm)
>
> Looking at the 2nd and 4th test set ups, the winch has a no load rpm of 400
> and 360, respectively. To make an equal comparison of torque output, the 2nd
> test should have had a no load rpm of 360, but I could not gear it that way
> easily.
>
> Taking the first two test set ups and fitting a line to the data (Torque vs.
> RPM), you can extrapolate to get the torque at a no load rpm of 360. The
> result is 12.8 N·cm, which is 2.33 times the torque of test 4 (the 71427 motor).
>
> -TJ
>
> notes:
> 1. Ratio means the additional gear reduction I built onto the motor. 1:1
> means direct drive- no gears.
> 2. The 5292 motors have two output holes. No load RPM are different for
> each: 1200 and 1700 (Ref. http://news.lugnet.com/technic/?n=7701 &
> http://news.lugnet.com/org/ca/rtltoronto/?n=6087).
> 3. 1:3 ratio: A set of 8t and 24t gears were added between the motor and winch.
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Message has 1 Reply:
 | | Re: 8475 Motor Tests
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| (...) Yes, I did too. Judging from the performance of the RC car, you'd think the motors would be equivalent to perhaps 8, or more, of the geared 9V motors. The buggy can really zip along! There was one other thing about my test. When the 9252 motor (...) (21 years ago, 8-Jan-03, to lugnet.technic, lugnet.robotics)
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Message is in Reply To:
| | 8475 Motor Tests
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| Last night I performed a few quick tests on the 5292 motors (the new motors from the 8475 Race Buggy set: (URL) to compare them to the standard geared 9V motor ((URL) summary, the 5292 motor (when geared down to match RPM of 71427) has about 2.33 (...) (21 years ago, 8-Jan-03, to lugnet.technic, lugnet.robotics)
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