Power Systems

Ededge2002 · March 02, 2013, 02:15:22 PM

A couple of guys have asked how to calculate motor efficiency. Motors should be run in the 75% plus range and the higher the better! wasted energy is wasted heat...

Another good thing to be able to figure is pitch speed.... The nooner gang should take a look at this calculator.

http://www.peakeff.com/CalcTP.aspx

http://www.rcpro.org/rccalc/PitchSpeed.aspx

Eric Adventurer · June 12, 2013, 01:24:02 AM

Quote from: battlestu on February 10, 2013, 06:29:10 PM
Or option three
http://www.flitetest.com/articles/Solder_Thick_Gauge_Wire

Option 3 is nice! Thanks for the tip.

Ededge2002 · October 06, 2013, 03:59:33 PM

Keeping it cool!

Figured I would post these pictures of how Joe Smith keeps his big high powered motors cool. A lot of his flying style would involve low airspeeds but I figure its some good food for thought for those tight cowl large scale birds too. Cooler motor provides more power through higher efficiency remember!

Ededge2002 · October 06, 2013, 05:00:18 PM

Notice anything in the last photo?

Papa · October 06, 2013, 06:48:16 PM

Looks like a computer cooling fan on a thermal switch.

Jack.

Ededge2002 · October 06, 2013, 07:03:20 PM

Quote from: Papa on October 06, 2013, 06:48:16 PM
Looks like a computer cooling fan on a thermal switch.

Jack.

The 6amp esc hooked to the micro ducted fan motor? or the finned block of aluminum on the back of the X mount? ...
As I understand from reading that was the best solution as he kept breaking the computer style fans from G forces!

Papa · October 06, 2013, 07:06:17 PM

The finned heat sinks made sense but that looked like a fan of some sort. EDF makes sense.

Outside the box thinking EH!

Jack.

Ededge2002 · October 06, 2013, 07:11:07 PM

Quote from: Papa on October 06, 2013, 07:06:17 PM

Outside the box thinking EH!

Jack.

Yes Jack I agree. I posted the photos because I liked the ingenuity.

Wingnutz · October 16, 2013, 09:53:14 PM

Figured I'd post this one here in hopes Dr. McMann and other experts might reply.
My Watts Up measured 7A and 80W from a single 3S battery supplying two small brushless motors each with its own ESC.
"How many amps are going through each ESC? 7A or 3.5A?"

Ededge2002 · October 16, 2013, 10:12:25 PM

Quote from: Wingnutz on October 16, 2013, 09:53:14 PM
Figured I'd post this one here in hopes Dr. McMann and other experts might reply.
My Watts Up measured 7A and 80W from a single 3S battery supplying two small brushless motors each with its own ESC.
"How many amps are going through each ESC? 7A or 3.5A?"

The motors are in parallel so the current would have two paths and the current will be split between the two motors. So 3.5Amps per motor.

Wingnutz · October 17, 2013, 06:41:44 PM

Thanks Ed...so if I'm running a 12A ESC on each motor and a single 3S battery, the system should be capable of well over 200W?

Ededge2002 · October 17, 2013, 07:58:11 PM

Quote from: Wingnutz on October 17, 2013, 06:41:44 PM
Thanks Ed...so if I'm running a 12A ESC on each motor and a single 3S battery, the system should be capable of well over 200W?

Motor and fan dependant but the esc's should be able to do 140ish each(280watts combined)

GuyOReilly · January 26, 2021, 11:31:07 AM

Extracted from Avro York project by @Michael , I hope you do not mind.

These diagrams show how to connect 4 motors.
I found these very helpful for my Lancaster project.

Split into 2 diagrams: motor-wiring and radio-wiring.
The BEC is shown in both diagrams.
The blue wire in the wiring-diagram represents the 3-wires from servos, throttles, retracts, etc. You do not have to cut anything.
If you want, some people suggest to cut the red (orange wire) to prevent interference, but I didn't cut anything, and I have no problems.