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Old 09-17-2008, 07:14 PM
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ktaylor
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Default RE: need help configuring an airplane for electric flight.

Not really the master, I've just experimented enough that I sort of know what works.

ok, so going off of Tower hobbies, the plane weighs in at 5lbs, to 5 lbs 10 ounces depending upon your set-up. So we'll aim for 6 lbs of static thrust or more. And since you're not looking for speed that helps.

The HXT motors from Hobby City really give you a lot of bag for the buck. I have 5 of them, had 6, and only managed to destroy one of them. That one died due to the ESC getting wet & cooking the motor as it died. One of them I gave to Brad for his 60 sized Sopwith camel since he kept having no luck with the E-flite motor. That motor had been through 5 or 6 crashes & still ran great, it even went head on into a tree. They've changed the name of the motors from Hextronic to Turnigy now though. You can also get the motors through Nitroplanes, remarketed as Alpha Motors and save on shipping time from Hong Kong.

6 cell li-po power option. Fully charged that's 25.2 volts, nominal voltage is 22.2 volts. Since it's a .46 sized plane, we'll go with the [link=http://www.nitroplanes.com/mo466brmo.html]MonsterPower 46 (670kv) Brushless Motor[/link]

Put a 12x6 APC prop on it, it will give you about 8 lbs of static thrust, (more than enough for hover), pulling 55 amps. On 6 cell that's 1100 watts at full throttle. Pitchspeed is 67 mph.

I'd use 2 of these battery packs, http://64.33.154.92/blackdogrc/lipo3...ABF40003s1p20c I have some of them in 3 cell and 5 cell. I've put a fair amount of abuse on the 5 cell packs, & am very pleased with them, the 3 cell packs are still new. Devaun (the shop owner) doesn't charge for shipping. With those packs, if you flew at full throttle the whole flight (probably not going to be doing that with a U-can do) you'd have a 5 minute flight, but if you fly normal, some full power & mostly 1/2 - 3/4 power, you'll have your 10 minute flight time no problem. If your radio has a timer, set it for 8 minutes so that you have an idea of when to start thinking about the normal landing stuff.

Here's a speed controller that would work well, http://lightflightrc.com/HTML/products/70A_ESC.htm You will need to use a receiver battery. There are high voltage Esc's that have the ability to power the receiver & servos built in, but most only have a 3 amp rating. If you start pushing your plane into some 3-d maneuvers you can exceed that 3 amp & oops, look there's some smoke. Never let the magic smoke out, things go bad when that happens. Plus if you want to run a 6 volt system, you're limited by the ESC, so it's easier to just use the receiver battery. Oh, and also more reliable, the battery gerates no RF noise like the UBEC can, & so long as you remember to charge the RX pack, you're good to go.

Hope that helps. Oh, and the numbers of amp draw & flight times, no gaurantees of that, but it gets you really close to the ball park. And with English no being your native launguage, it is mine & can't always use it correctly either.