need info on esc and motor
11-07-2004, 11:12 AM
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need info on esc and motor
I have a p 38 from hobby lobby.i am using 2- mega 16-15-5 brushless motor
that say 20 amp max
2- jeti esc rated 18 amps
with 6x4 lpc props amps are 23.5 watts 2400
with 7x5 lpc props amps are 38 watts 3900
i am using thunder power 11.1 volt lipo packs 4200
i have flown with smaller prop and it flys good. are these figure too
high for the larger prop. this is my first venture in to electric .
but with the good luck i have had so far it is not my last.
that say 20 amp max
2- jeti esc rated 18 amps
with 6x4 lpc props amps are 23.5 watts 2400
with 7x5 lpc props amps are 38 watts 3900
i am using thunder power 11.1 volt lipo packs 4200
i have flown with smaller prop and it flys good. are these figure too
high for the larger prop. this is my first venture in to electric .
but with the good luck i have had so far it is not my last.
11-08-2004, 06:16 PM
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RE: need info on esc and motor
38 Amps is too much. Remember, the motor manufacturer says 20 Amps MAXIMUM.
Two things that would cause the large jump in Amps:
1. Propeller load does not scale in a linear fashion. The "swept disk" of a 7" prop is 1.36 times the size of a 6" prop. From that, you should be expecting AT LEAST a 36% increase in Amps. That's about an 8 Amp increase over 23 Amps, MINIMUM.
2. The motor is well beyond its most efficient levels at 20 Amps. Heat is starting to build up. The further beyond 20 Amps you go, the more heat builds up, and the quicker it builds up. As the heat builds up, the motor becomes less and less efficient, requiring more and more Amps. Eventually the motor's windings get too hot and burn up.
Two things that would cause the large jump in Amps:
1. Propeller load does not scale in a linear fashion. The "swept disk" of a 7" prop is 1.36 times the size of a 6" prop. From that, you should be expecting AT LEAST a 36% increase in Amps. That's about an 8 Amp increase over 23 Amps, MINIMUM.
2. The motor is well beyond its most efficient levels at 20 Amps. Heat is starting to build up. The further beyond 20 Amps you go, the more heat builds up, and the quicker it builds up. As the heat builds up, the motor becomes less and less efficient, requiring more and more Amps. Eventually the motor's windings get too hot and burn up.
11-10-2004, 06:22 PM
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RE: need info on esc and motor
Oh, is that 38 Amps for BOTH motors? Then completely disregard what I said.
38 Amps total, for both motors, would be 19 Amps per motor. That means you're within the motor's rated capacity.
38 Amps total, for both motors, would be 19 Amps per motor. That means you're within the motor's rated capacity.
