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I need two motors powerful enough to accelerate a 200 lbs robot at 10 ft/s^2. From doing the calculations, I know I am looking for a two 430 watt motors. I found the Falcon 500 motor on vex robotics website. But those motors are only 3 inches in length and weigh 1 pound. They are advertised to be able to provide the necessary 430 watts, but it is extremely hard to believe this due to its small frame and weight.

If anyone has had first hand experience with the Falcon 500 and used them to power and maneuver heavy robots, please tell me if two falcon 500 motors would be sufficient for this project.

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It depends on how many seconds you want to run the motors, and how many minutes you want to wait between runs.

Those motors are certainly not going to operate at 430 watts continuously. At 40 amps, the "brochure" suggests a 32C rise at 150 seconds, and the motor data shows an overtemp shutdown at 260 seconds.

They are targeted at the FIRST community, so if you don't abuse them I'd expect them to work really well, for a few months at least.

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  • $\begingroup$ The robot is being designed to play racketball versus a human. Therefore the motors wouldn’t run constant but instead in 5-6 second spurts and then rest for 4-5 second then on again for 5-6 seconds. In the event that motors are on, they are expected to produce 430 watts of power each to the robot for those 5-6 seconds if we feed the motors 50 amps during this time. Does this sound feasible? We found that 50 amps is required to produce the 430 watts from the falcon 500 user guide. $\endgroup$ Jan 12 at 0:43
  • $\begingroup$ Referring to the temp graph in what I called "brochure", and the constant current plot at the motor data link, I'm thinking these motors will not be feasible. Except maybe if you have active cooling, and even then it takes (extrapolating by eye) four times as long to cool off as it does to warm up. You're running at >50% duty cycle. Just maybe it could manage a shortish match. Note that the human has active cooling (evaporative and convective) and also takes a while to cool off! $\endgroup$
    – r-bryan
    Jan 12 at 1:01
  • $\begingroup$ From my experience mentoring a FIRST robotics team, I don't think I would want to be on a racketball court with a 200 pound robot with more horsepower than a horse. My team's robot went berserk after a burst of WiFi packet corruption, and only a student's nimbleness saved her legs. Nobody should have to deal with that kind of "crush"! $\endgroup$
    – r-bryan
    Jan 12 at 1:09
  • $\begingroup$ We know the motors will have a “shortish” run time and this is more or less a pilot project. We planned on using a 12volt 30 amp-hr battery. So it would have approximately a 15 minute run time. But keep in mind that the motors only run in spurts. Does this information, change your mind from the falcon 500 not being feasible? $\endgroup$ Jan 12 at 1:11
  • $\begingroup$ I suppose so, if three-minute matches are adequate for your demo. The motors will shut down to protect themselves from overtemp before the battery runs out. At your 50 A, the constant-current graph shows thermal shutdown at around 110 seconds. If you're running, say, 55% duty cycle, with negligible cooling between bursts, that's barely three minutes. Active cooling will stretch but not double that. Budget for replacement motors if you routinely push it to protective shutdown. And if your software developers are like me, they will hate having to wait for it to cool between bursts :-) $\endgroup$
    – r-bryan
    Jan 12 at 15:33

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