larsb
1 MW
I will rewind a Revolt RV 120 pro motor to see if i can improve performance. It will be my first wind so that's where the headline comes from
Some measurements of original stator (rough figures since windings are still in place):
Approximate stator slot area: 190 mm2 (slot bottom width:6, top width:15, radial slot height:18)
Copper area in slot: 2(sides)x12(turns)x5(strands)x(single wire area)
Single wire area: 3.14*0.8^2/4 = 0.50 mm2
--> Copper area in each slot: 60 mm2
fill factor: Area copper / Area slot: 60/190= 32 %
That is low. I am looking forward to the rewind as it seems to be possible to make a big difference.
Max fill possible in ideal conditions can be viewed here:
https://www.emetor.com/blog/post/how-big-maximum-possible-slot-fill-factor-using-round-conductors/
Wire diameters between 2-3 mm seem to be optimal, although i think large wires will be really hard to wind.
I am surprised to see such a big effect of the type of insulation!
I will be aiming for at least 65% fill and plan to use 14awg square wire in 2 parallell strands for as many turns as can be fitted.
If someone has tried 14awg wire for a rewind of a motor this size then i'd like to hear your input. Is it too stiff to handle?
Some measurements of original stator (rough figures since windings are still in place):
Approximate stator slot area: 190 mm2 (slot bottom width:6, top width:15, radial slot height:18)
Copper area in slot: 2(sides)x12(turns)x5(strands)x(single wire area)
Single wire area: 3.14*0.8^2/4 = 0.50 mm2
--> Copper area in each slot: 60 mm2
fill factor: Area copper / Area slot: 60/190= 32 %
That is low. I am looking forward to the rewind as it seems to be possible to make a big difference.
Max fill possible in ideal conditions can be viewed here:
https://www.emetor.com/blog/post/how-big-maximum-possible-slot-fill-factor-using-round-conductors/
Wire diameters between 2-3 mm seem to be optimal, although i think large wires will be really hard to wind.
I am surprised to see such a big effect of the type of insulation!
I will be aiming for at least 65% fill and plan to use 14awg square wire in 2 parallell strands for as many turns as can be fitted.
If someone has tried 14awg wire for a rewind of a motor this size then i'd like to hear your input. Is it too stiff to handle?