Basic Motor Project

Thread Starter

aclarke97

Joined Dec 30, 2020
5
Hey I have 12v dc motor I'm trying to attach nichrome to it to heat it up with a hand crank. Basically winding one end with the crank to heat up the nichrome but it isn't heating up. Do I need resistors or a higher voltage. I have about 3 Inches of nichrome on it so far but its not working.
 

MaxHeadRoom

Joined Jul 18, 2013
21,984
Appears you do not have the motor capacity. You need a high voltage motor of suitable power, then you can regulate just by RPM.
Max.
 

Thread Starter

aclarke97

Joined Dec 30, 2020
5
You are using a motor to act as a generator to heat up nichrome wire?
Not going to happen.
Not even a motor with a high voltage? I have a gear set hooked up to everything to keep cranking. I know that a 12v battery can heat nichrome easily which is why I’m testing it out with a dc motor.
 

Thread Starter

aclarke97

Joined Dec 30, 2020
5
Not even a motor with a high voltage? I have a gear set hooked up to everything to keep cranking. I know that a 12v battery can heat nichrome easily which is why I’m testing it out with a dc motor.
It’s confusing how can a 12v battery heat up nichrome but a motor with equivalent or greater power not? Sorry this is new to me.
 

MrChips

Joined Oct 2, 2009
22,505
Do the math.
Suppose you want to heat up a resistor with 24W using a 12V battery.
You need to deliver 2A into a 6Ω resistor:

P = I x V
I = P / V = 24W / 12V = 2A
R = V / I = 12V / 2A = 6Ω

What is the resistance of your nichrome wire?
How much power can your motor/generator deliver into the nichrome wire?
 

BobTPH

Joined Jun 5, 2013
2,730
Not if you’re hand cranking it. Unless you have super powers and can crank several thousand or ten thousands of RPM. Even then, I don’t think so...
Ha! An olympic cyclist was able to make toast by pedaling in a famous video I am too lazy to look up. He was, however, totally exhausted when he finished.

Bob
 

Thread Starter

aclarke97

Joined Dec 30, 2020
5
Do the math.
Suppose you want to heat up a resistor with 24W using a 12V battery.
You need to deliver 2A into a 6Ω resistor:

P = I x V
I = P / V = 24W / 12V = 2A
R = V / I = 12V / 2A = 6Ω

What is the resistance of your nichrome wire?
How much power can your motor/generator deliver into the nichrome wire?
Its 28g on 80wire and the motor is a 12v dc motor.
 

BobTPH

Joined Jun 5, 2013
2,730
Yes, but he produced probably 100 times the power needed to heat a little piece of nichrome wire to some unspecified temperature.

Bob
 
Yes, but he produced probably 100 times the power needed to heat a little piece of nichrome wire to some unspecified temperature.

Bob
By spinning a car alternator at several thousand RPM. A DC project motor by comparison is probably going to max out at tens of watts at those same speeds - it sounds like OP is dealing with tens of RPM at best.

Voltage from a generator is a function of lines of flux cut per second - meaning essentially RPMs times turns of copper wire times magnetic field strength. A car alternator can develop a much stronger field than a small hobby motor.

Point being OP's troubles probably stem from spinning way too small of a motor way too slowly. If he were to take e.g. a treadmill motor and spin it up to 1000-4000RPM on the other hand... *that* would likely generate a kilowatt or two.
 

Audioguru again

Joined Oct 21, 2019
2,374
A guy connected a huge fan to his bicycle to generate electricity to light LEDs at night. He said it was hard work to make the fan spin by pedaling fast, like pulling an open umbrella. The big fan was replacing a cheap little battery.
 

djsfantasi

Joined Apr 11, 2010
7,210
Basically, my response to the original post stated that it was unlikely that hand-cranking a DC motor would work. Others pointed out other methods that wouldn’t work or worked with extreme restrictions, that was non-responsive to the TS original question. On top of all that, when was the last response from the TS?
 
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