Author Topic: Choose an electric power setup?  (Read 14974 times)

goreyflyer

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Re: Choose an electric power setup?
« Reply #15 on: June 19, 2016, 20:11:02 PM »
Spoken like a true motorcycle instructor!!!!



But power is brilliant !!  ;)

angry_muppet

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Re: Choose an electric power setup?
« Reply #16 on: June 19, 2016, 22:35:05 PM »
Oh what fun!  :)

4000mAh battery
Aerodrive SK3 - 2836-1040kv Brushless Outrunner
30mm stand off mounts - The motor "can" is 40mm; the available space from the front of the fuselage to the firewall is 80mm; is there any issue with using these little guys as well? (10mm spacer)
Prop adapter w/ Steel Nut 3mm shaft This lad will allow me to use the original spinner (I hope)
14x7 prop? Unfortunately, it's the only prop that might be suitable I seem to be able to find in the UK warehouse...?

So far, I estimate an AUW of approx 2.1kg; this gives a wing loading of ~48g/dm2 (15.8oz/ft2).  Slightly heavy, but reasonable.

I'll also need bolts?  :-\

Happy Days

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Re: Choose an electric power setup?
« Reply #17 on: June 19, 2016, 23:11:24 PM »
Motor mounts.....Best to keep the motor as close to the firewall (and consequently as close to the CoG) as poss.

4000mAh battery?.......that's a big battery for such a model, 3000 or 3500 would be lighter. (Your choice of course.)

14x7 prop...Hmmm The motor is designed for a max load of 28amps. I would have thought a 14x7 prop would likely overload it. :( If the model was last flown with a 10x6 that's the size to be aiming for really. You'll get a longer flight time with a smaller prop as an added bonus! ;)

15.8oz / sq ft is a good wing loading for a trainer! 8)

Goreyflyer;...yes my days of wheelies, stopies, and burn-outs are long gone,...along with my handsome looks and masculine physique! (But I'll have the memories forever ;D )

K.
Try not to run out of airspeed, altitude and ideas....... all at the same time.

angry_muppet

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Re: Choose an electric power setup?
« Reply #18 on: June 20, 2016, 06:53:46 AM »
The reason for the stand off mounts is that the "nose" in front of the firewall is 80mm. As the motor is only 40mm, I either need to use stand offs or cut the nose back; I'd prefer not to modify the airframe too much.

I wouldn't be particularly concerned about the CoG; the original OS motor is 250g and the SK3 is only 80g.  Putting it further out should approximately replicate the glow motor and reduce the need for ballast?  I assume using the stand offs does increase the potential for "flex" in the motor position?