rainedave

My Feedback: (1)

Hi. I have an old Goldberg Tiger 2 (Wingspan: 61" Wing Area: 680 Sq." Flying Weight: 5.25 lbs. Power: .35-45 2-Cycle).

I feel like this would be a great conversion project to get into electric flight; I have never flown an electric r/c plane before.

There seem to be hundreds if not thousands of electric motors on the market, and for every one there are several versions. For example, in the AXI 2800 series there are eighteen different versions. And that's just one model of one brand! And that's just direct drive. Mutiply 18 by the available gearboxes. How would one know which one to buy? OS does not make 18 different .40s if you see what I mean.

I would like to convert this plane to electric, but I have no interest in buying a dozen motors, a dozen battery packs and a bunch of props just to see which combination performs the best.

If someone could advise or point me to a resource I would greatly appreciate the help.

Thanks, David

viper16

This seems to be a growing trend because I too would like to convert a pica cessna 182

Wingspan: 89"
Weight W/O motor: 10 lbs.
Wing Area: 984


And like you have know idea about electrics and have to start, so hopefully 1 you don't mind me tagging onto your post, and 2 in hopes that we can both be enlightened.
Greg

rainedave

My Feedback: (1)

I'm glad you did! Now I know I'm not alone in all this.

In the 3/05 MA was a table that gave ball-park numbers for how many watts you need per lb. of plane/type of flying/wing loading.

If it helps, the Tiger 2 should weigh between 80 and 96oz, have a wing loading between 18 and 20oz and be able to do basic aerobatics like loops, stall turns, inverted, Cuban 8s, etc. It by no means would need unlimited vertical of hovering abilities.

Using the MA table, I would need between 300 and 480 watts for this plane to act like it had a forty. Now, I can do the amps and volts math to get the necessary wattage, but that provides no help in knowing what brand or type of motor to consider.

kihei11

My Feedback: (13)

I was there once too. it depends on what you want to do, If I were you I'd go to hobby lobby's web site and check out there glow to electric conversion aircraft and copy the set up they used for a similar plane. My 1st conversion was a 40 size trainer, I used a cheap 16 t electric truck motor a great planes gearbox and 12x8e prop on 10 cells it's no speed demon but it's still flying after almost 2 years. good luck go to Greg Covey's web site--Matt kirsh is also one of the best[:-]

afineman

Hey guys

The questions to ask is how much do you want to spend, what kind of performance, and flight duration would be pleased with?

For rainedav, my brother and I just completed and videoed the maiden of a Nexstar.

There are still a few kinks that need to be worked out (best prop and CG) but this was electrified for $210 ($130 of that was for batteries for long duration)

http://media.putfile.com/4-15-06A the winds were gusting that day.

And for viper16, the cost may be about $80 more with this motor http://www.warbirds-rc.com/Store/hett291810.html ( note the model weight it is good for)

This brushless speed controller http://www.bphobbies.com/view.asp?id...93&pid=V470156

A pair of these batteries 22812 DYMOND Lipoly hd 3000 12C 14.8 V 346g 140x43x24 mm PC board for easy soldering and parallel packing. Ideal power pack to use for big power airplanes. A4S 2P pack would be good for 58 A draw and weighs only 700 g with 6000 mah capacity.

Would do the job nicely.

If you want to pursue this and need some guidance, I'll help.

Hope it helps

Brent

algutkin

My Feedback: (1)

Where to start?

There are three web sites that will give you all the info you want,

Hobbylobby.com
Fmadirect.com
Greg Covey

There is nothing different about flying an electric powered plane, they fly the same, and your transmitter doesn't know the difference. If you want to save money and valuable time, best bet is to read and gain some knowledge. The Hobby Lobby and FMA web sites contain a wealth of info and they contain power setups for already converted planes simlar to yours. The info is right there for your eyes to see. I wouldn't bother Greg Covey with this type of question, as he seems to be extremely busy with his position as marketing manager for FMA, however, his web site contains more info than a normal person can absorb. Read it all, memorize it, and you will be a electric RC genius.

Al G.

rainedave

My Feedback: (1)

Thanks everyone. I'll do some research and I'm sure I'll have more specific questions soon.

destructiveTester

I have found this electric flight calculator really useful too:-

http://brantuas.com/ezcalc/dma1.asp