cholubaz

Is there any advantage to going with a higher amp ESC than you need?

Here is what I'm working with:
plane is a Hyperion Super Chipmunk 70e http://www.allerc.com/chip70.htm
Engine is a PJS 3D 3000 Brushless Outrunner Motor http://www.visionhobbies.com/1148299.html
Weight 12.17 ounces. For 12-16 cells or a 4s 14.8v LiPo, dimensions 53x103mm, max efficiency 43A, RM 35m ohms, RPM per volt 496, recommended props 14x6, 17x8
Battery's I think I'm going to use 2 4S 14.8V 2200mAh Lipo's Continuous Discharge Rate: 28c Burst Discharger Rate: 35c in parallel

For example if I got a 120A ESC Brushless Motor Speed Controller 5A BEC would that be any advantage to me VS a 70A or 80A ESC?



Thanks,
Chris

DaveFlynn

No. It will work, but why carry the extra weight. Also, 4S on a 500Kv motor wont get you a lot of rpm. Try a Castle HV-30 and 8S1P 2200mAh pack with a 12x6 prop.

Dr Kiwi

I saw an ad which suggested a 560Kv motor, with 14x8 on 5s... that would get you a lot more rpm than 500Kv on 4s.

12x6 on 8s... I know it would be spinning at high rpm, but is 12" diameter enough to get you decent thrust without excessive pitch speed?

DaveFlynn

My latest, an Extra 300, with a 380Kv motor likes a 13x6. It flies well, no 3D, at half throttle on a 9S1P 2100mAh. Prop choice is more for your flying style, trust vs speed, than the motor. The most important thing is to watch the amps so you don't burn up the battery or exceed the max amps for the motor.

SD2006

There can be, it depends on howyou determine the size you"need". Amp ratings alone don't tell the whole story. You don't want a hot running ESC.

nick_cool

Yes, I always use bigger ESC, they are more efficient and are more tolerant to abuse, specially if they are not well ventilated. Same thing with happens the BECs.

tkilwein

A bigger esc will have less internal resistance (means more gets to the motor) you will get a little more out of the setup.
I use 25-50% more than needed for this reason and also to not heat up the fets in the esc as much, full stick for 3+ minutes at a time.
I have setups that pull 80-90 amps at 25v 6cell and it is very measurable at these voltages and currents, over 2100+ watts.

cholubaz

Thanks guys for your input. It's what I expected that a bigger ESC than what is called for by the motor is a good thing. As far as the one comment "It will work, but why carry the extra weight" I'm not flying a foamy. I'm flying a 6.5 7 pound Chipmunk and I don't thing the difference will be felt at all.
Im leaving for a vacation today and will be back next week. I have everything finalized with this plane now and will have it in the air probably on Wed the 15th.
Cheers,
Chris

ron_van_sommeren

About de-rating controllers and motors, starting at 'for everyone else':
http://www.rcgroups.com/forums/showt...0#post11476940

Vriendelijke groeten Ron