3 1/2inch CIM motor info

[DarkFlame145]

I need to find the RPM of it aqnd how much energy it puts out.

[kramarczyk]

My wife always accuses me of being a pack rat... I've no idea what she is talking about.

[writchie]

Originally Posted by DarkFlame145

I need to find the RPM of it aqnd how much energy it puts out.

The motors curves are on page 5 of the 2008 FIRST Guidelines, Tips, & Good Practices.

Like all motors the RPM's depend on the torque load. Since you can power this motor from at most a 40 amp breaker, if you want to run continuously your torque load will need to be about 100 oz-in and your RPM with that load will be about 3800 RPM. Your mechanical power will be about 280 watts with an efficiency of about 59%. Your motor will produce about 200 watts of heat, same as two 100 watt light bulbs.

Energy is POWER x Time. So the energy produced (really converted) by the motor is a function of how long you run it. Since 1 Watt is 1 Joule per second, the mechanical energy you can get is about 280 joules per second.

The motor has a maximum power of 337 Watts but at that level you would be drawing 68 amps and pumping .8 kilowatts 1/2 of which will come out as heat. Since this would be a 170% load on the breaker, you could probably do this for maybe 5 to 10 seconds before popping the breaker. You will see max power on this motor with a torque of 172 oz-in and with that load your RPM will be about 2670 until your breakers pop and it drops to zero.

All of the above are at 12V, roughly equivalent to fully charged battery and minimal other loads. Since a 68 amp will pull down the battery voltage, you will not likely get much more than about 280 watts from a single CIM.

SORRY - ALL OF THE ABOVE IS FOR THE CURRENT YEAR CIM. You do know that the big CIM's from last year are not
legal for competition.

The "PIMP" CIM's will draw 40 amps with a torque load of 230 oz-in and with that load will turn at 1500 RPM. This equates to 255 watts and an efficiency of about 53%.

[DarkFlame145]

thank you very much, this is exactly what i needed. See we are going to use one to make a peddle power generator, if it's worth using to charge batteries at our local Relay for Life. Also it will show off new energy (although this is not very practical =P)

[motosaurus]

Did you build that pedal powered generator?
How did it work, I am thinking of one for an electric bicycle-like thing.

John

[Qbranch]

Originally Posted by kramarczyk

My wife always accuses me of being a pack rat... I've no idea what she is talking about.

Well... if I were you I'd take that acusation as a compliment. I lost my copy of this PDF somehow and... *plays Reunited* well, I'm glad we're back together.

Thanks Mr. Gearhead! Amazing what you run in to when you aren't looking for it...

-q

[kramarczyk]

Need the missing DeWalt trans CAD or some old kitbot documentation? I can't seem to find that 20 minutes of the Nixon tapes though.

[Richard Wallace]

Originally Posted by kramarczyk

I can't seem to find that 20 minutes of the Nixon tapes though.

It was 18.5 minutes, and I can't find 'em, either.

[kramarczyk]

Originally Posted by Richard

It was 18.5 minutes, and I can't find 'em, either.

Mine was a copy, so it must have had some extra on it.