converting a top flite contender - RC Groups
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Jul 11, 2001, 04:58 PM
crazy builder
flying_pig's Avatar

converting a top flite contender

I am thinking of converting a top flite contender to electric and would like to use a geared de-walt 14.4 motor and 12 cells. What speed controll would i need? Also has anyone else converted a contender and can offer any advice?
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Jul 11, 2001, 05:13 PM
Time for me to Fly...
Mr. Wiz's Avatar
The TF Contender is a pretty big plane. I think you're looking at a 16 cell system as a minimum and probably 20 cells if you want to preserve its aerobatic personality.

Jul 11, 2001, 05:24 PM
jrb's Avatar
Check out the FAQs for other rules of thumb; but the 16 to 20 cell count is correct.

A recent RoT suggested 100 watts for each 0.1 cubic inches of displacement, per plans 400 to 610 watts.

Propped for 30 amps, 12 cells (12 volts @ 30 amps) is about 360 watts; good for a lighre .40 ship.

Going brushless with a Maxcim Y wouldn't be a badd choice.
Jul 11, 2001, 05:26 PM
KOMET 44's Avatar
Get the specs on the plane then post that.Can't do anything until you know that.stefanP
Jul 11, 2001, 05:38 PM
crazy builder
flying_pig's Avatar
the url for the contender is and according to the top flight site the specs are

Stock Number: TOPA0210
Wingspan: 53.25 in (1350 mm)
Wing Area: 660 sq in (42.6 dm2)
Weight: 6-6.5 lb (2720-2950 g)
Wing Loading: 21-23 oz/sq ft (64-70 g/dm2)
Fuselage Length: 49.6 in (1260 mm)
Requires: 2-stroke .40-.61 cu in (6.5-10 cc) or 4-stroke .52-.70 cu in (8.5-11.5 cc) engine, 4-channel radio w/5 standard servos (5-channel w/6 standard servos if flown with optional flaps)

I would like to use a de-walt motor because i work for work for them.
Jul 11, 2001, 06:49 PM
Recruiter - 60 Amp Club
Ed Lyerly's Avatar

The Contender is too much airplane for the DeWalt motor and 12 cells. It is sturdily built [heavy] and would require much re-engineering to be successful. Suggest you obtain Dec '99 EFI magazine & or plan MW 2769 for the "Moose". It is a 54" 530 sq in ship that I have seen fly ....and fly well with the DeWalt 18V motor and 14 cells.
Jul 12, 2001, 11:54 AM
crazy builder
flying_pig's Avatar
A friend showed me his old contender and yes i agree the thing is built like a battleship, it reminds me of a big control line model where weight saving has been passed over in favour of strength so i'm looking to build something else now, thanks for all the advice
Jul 12, 2001, 12:23 PM
Build'em and Crash'em
Ken Lapointe's Avatar
The Top Flite Contender makes a great conversion. I used an Astroflight 40G on 20 cells with a 13 x 8 prop. I have pictures and info in the gallery at

I think 18 cells would be the minimum for this plane.

Jul 13, 2001, 12:31 PM
Balsa Flies Better!
Re weight on the Contender- Not true! I built two of them glow, and it was a very light glow ship, and unless the new version has been beefed up unmercifully, it probably still is. C/L stunter construction is actualy pretty light.

The airplane has a thick wing though-which means it doesn't really stall, but is kind of slow on the top end. Gearboxes should be a big plus- your worse problem will be ground clearance- I had trouble with a 12" prop on grass.

Sam Brauer
Norwalk, CT
Jul 14, 2001, 09:48 AM
Registered User
Martin Irvine's Avatar
That thick wing will need some horsepower to pull it. The originals were light and had good vertical but not a lot of speed unless a larger engine was used.
You could use the DeWalt in a gearbox but direct drive would probably limit you to 9 or 10" props and 14 cells. That would work if you could keep the weight to 80oz. (5lb) total, but it wouldn't be a great flier. And you wouldn't likely make that weight.
A belt drive will add another 6 oz. to your power system, (and the DeWalt already weighs 16 oz).
Ed suggested the "Moose" plan from EFI. I designed that around the DeWalt motor to make the most out of a direct drive situation. I'll bet it is lighter than the Contender.


Jul 14, 2001, 10:19 AM
The Great and Powerful Oz
Woody's Avatar
The original Contender was much heavier than the new version, but it would still not make a good candidate for conversion. The one I had many years ago was powered by a Super Tigre .51, and it was adequate. You would need lots of cells to get good performance, and the weight would be a killer.