101
Coil winding / Re: How to determine the limits of a coil / magnet configuration
« Last post by brandnewb on April 12, 2024, 02:09:25 PM »I am not ready at all
You see the gravity torque test is not working out
It is proving really difficult to get the PMA rotating at the intended speed with the coils closed.
So for a 29 leg coil of 5x 0.4mm litz wire I got only around 22 watts. (I had to wind the coil a little less than the intended 31 legs because I never realized that when adding wires in parallel we will need more length so I ended up short thus the 29 coil legs )
I dropped a weight of 6 kg from 2.163 m height.
and open coil it took 4.95 sec
closed coil it took 45.32 seconds but the end speed was nearly not high enough as the intended speed.
I can add weights but there will always be a ramp up time needed and also then the disk would start spinning far too fast with the coils open.
Either I do not get how to properly conduct the gravity torque test or it is just not applicable in this scenario.
I do think though that this 5x 0.4 litz wired coil is not better than a single 1mm wired coil as the area is still less.
0.4 mm diam = 0.12566 mm2 * 5 = 0.6283 mm2
1 mm diam = 0.7854 mm2
what a complete waste having bought huge spools of 0.4 and 0.71mm wires.
if anyone can think of a good use for that?
I am now looking for a reliable way to measure the amps in the coils while shorted so that i can have the motor spin at the intended speed and then calculate the wattage the coils produce.
What would be the best tool to do that an accurate amp measurement?
You see the gravity torque test is not working out
It is proving really difficult to get the PMA rotating at the intended speed with the coils closed.
So for a 29 leg coil of 5x 0.4mm litz wire I got only around 22 watts. (I had to wind the coil a little less than the intended 31 legs because I never realized that when adding wires in parallel we will need more length so I ended up short thus the 29 coil legs )
I dropped a weight of 6 kg from 2.163 m height.
and open coil it took 4.95 sec
closed coil it took 45.32 seconds but the end speed was nearly not high enough as the intended speed.
I can add weights but there will always be a ramp up time needed and also then the disk would start spinning far too fast with the coils open.
Either I do not get how to properly conduct the gravity torque test or it is just not applicable in this scenario.
I do think though that this 5x 0.4 litz wired coil is not better than a single 1mm wired coil as the area is still less.
0.4 mm diam = 0.12566 mm2 * 5 = 0.6283 mm2
1 mm diam = 0.7854 mm2
what a complete waste having bought huge spools of 0.4 and 0.71mm wires.
if anyone can think of a good use for that?
I am now looking for a reliable way to measure the amps in the coils while shorted so that i can have the motor spin at the intended speed and then calculate the wattage the coils produce.
What would be the best tool to do that an accurate amp measurement?