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# Calculating RPM of electric motor

## Calculating RPM of electric motor

(OP)
Good evening

I would like to calculate the RPM of my electric motor. The motor will be mounted on a car and will have to move a mass of approximately 500g. I know that the RPM at 1.5V with no load is 4242 RPM., current of 0.042 A. At maximum efficiency I have 3296 RPM, 0.151 A, Torque 6.8 g-cm, 0.345 W of output Power. Does anybody know how to calculate the required RPM? many thanks guys. :)

### RE: Calculating RPM of electric motor

Power, torque, rpm. All related.

### RE: Calculating RPM of electric motor

I see nothing in your statement of the problem that would limit the rpm to a particular number.

### RE: Calculating RPM of electric motor

Work out what torque you need to do your duty. You haven't said and we don't know. You've told us some irrelevant info like it's on a car and the mass it has to move but missed out the vital data.

Then either do some tests oo find the torque speed curve for your motor. Simple.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

### RE: Calculating RPM of electric motor

how much work is required to move your 500g ?

notice too your units are all over the map ... torque in "g.cm" ?? need Nm, rpm to sec^-1, then you can check your power in Watts.

I 2nd MacGyverS2000 ...

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