How do I determine the power of my motor?

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To determine the power of a motor taken from an old printer, users should start by researching the motor's part number, such as RS-385SH, to find specifications and parameters. Modifying the motor to achieve higher RPMs, like 29,000, is challenging; instead, using a gear ratio can effectively increase RPM while managing torque. Suggestions include using fewer turns of larger wire to enhance speed, but this requires careful consideration of back EMF and current. Gears are recommended as a simpler solution for increasing RPM without extensive modifications. Additionally, exploring junk shops for discarded high-speed motors from battery-operated devices may yield useful alternatives.
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http://pokit.org/get/698d568001a73aa07d3a98d9ad7672c6.jpg

This has been take out of old printer. I also found a stepping motor.

I want to use this for my heli project.

http://www.angelfire.com/blues/heli_project/main_body.htm

They suggested brushless modification of motor from CDrom. I am holding that for last reserve.

How do I know what are the parameters of this motor? What power it needs etc.
 
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http://www.mabuchi-motor.co.jp/cgi-bin/catalog/e_catalog.cgi?CAT_ID=rs_385sh

always google the part number and you may get lucky :wink:
 
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I did google it. I didn't get lucky :/

Thank you.
 
weird, I enter "RS-385SH" and I get lots of hits
 
DragonPetter said:
weird, I enter "RS-385SH" and I get lots of hits

Then miss typed something :D Thank you. Now I have to figure out physics or RC chopper.But I think this motor will do.
 
Ahhh yes. Now I see in history. I typed R8 instead of RS :D
 
DragonPetter said:
You want to go higher than the max unloaded RPM of 29,000?

No no I meant the motor I have, to modify to have at least 29,000. its max is 10,000.
 
  • #10
Bassalisk said:
No no I meant the motor I have, to modify to have at least 29,000. its max is 10,000.

You probably wouldn't want to try, and I'm not sure what the equations for it are but you'd want a larger back-EMF on the coils since your RPM is directly proportional to that parameter.

You're probably better off finding a simple and cheap gear ratio assuming your motor can supply more torque than your max you will need. You will get higher RPM, but less torque if you step up the revolutions with a gear.
 
  • #11
DragonPetter said:
You probably wouldn't want to try, and I'm not sure what the equations for it are but you'd want a larger back-EMF on the coils since your RPM is directly proportional to that parameter.

You're probably better off finding a simple and cheap gear ratio assuming your motor can supply more torque than your max you will need. You will get higher RPM, but less torque if you step up the revolutions with a gear.

Gears. Of course. Forgive my troubled mind, college has taken away my creativity :(
 
  • #12
i'd think fewer turns of larger wire would give more speed

back EMF = K * flux * rpm

and field flux is set by permanent magnet .
so with fewer turns the rotor will have to turn faster.
In other words, K includes number of turns.
Current will be higher so put in biggest wire you can fit.
but centrifugal force is square of speed - brace them in well.
 
  • #13
Bassalisk said:
Gears. Of course. Forgive my troubled mind, college has taken away my creativity :(

Hopefully that's a possible option, but remember to check if it will give you the required torque at those higher RPMs.
 
  • #14
DragonPetter said:
Hopefully that's a possible option, but remember to check if it will give you the required torque at those higher RPMs.

It probably will. I find this motor to be very robust. Little math will probably confirm that.
 
  • #15
jim hardy said:
i'd think fewer turns of larger wire would give more speed

back EMF = K * flux * rpm

and field flux is set by permanent magnet .
so with fewer turns the rotor will have to turn faster.
In other words, K includes number of turns.
Current will be higher so put in biggest wire you can fit.
but centrifugal force is square of speed - brace them in well.

I will probably go with gears, since motor is well tucked in, with no screws or anything.
 
  • #16
gears sure sounds easier.
just a thought -
check junkshops for battery operated small vacuum cleaners, little dustbusters and the like.
They have a very powerful high speed motor inside.
Frequently they are discarded when batteries give out.
 
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