Duelist Twin Conversion

[Robyn_r]

This is actually my third conversion after my LT-40 ARF and my (originally) rubber-powered Right Flyer.

I was given this Pica Duelist powered with a pair of O.S. 25 glow engines and no other equipment. It is painted up in the livery of a WWII-era Italian bomber. As close as I can figure, it was built sometime in the 70's.

I had a laundry list of mechanical refurbs including freeing (and lengthening) the landing gear, building servo mounts, assembling linkages and re-installing radio gear and servos.

The other part of the equation was determining the E-powerplant and batteries. I chose to use 2 Mega 22/45/3 brushless inrunners each powered by it's own 4S1P A123 pack through a Castle Phoenix 45 controller. The props are Master Airscrew 11x8 3-blade props and it all pulls about 34 amps static for 394 watts (close to 800W total). I'm not sure of the AUW but estimate it in excess of 10 lbs.

The servos are Standard Hitec HS-422 (rudder, elevator, 2 for ailerons) and I have a separate 4S Nicad pack (no BEC).

It flys!!! We maidened it this evening in 6 mph winds and it took off very sweetly. We did 3 laps of the field in 3 minutes (all WOT) and landed (breaking the tail-wheel mount). Only pulled 699 mA out of the 2200 capacity so I figure I'm good for 7 minute flights WOT, a bit more with throttle management.

Now to repair that tailwheel and learn to fly it for myself for this weekend's Mid-Am Fly.

[Robyn_r]

Update... I've flown it myself.. A very surprising amount of power for takeoff.. Up in 10 feet on the propellors!

I've gotten around to weighing it. AUW of 9.5 lbs for 83 W/lb power ratio..
I figure I'm good for 6-10 minute flights.

[Dereck]

Hi Robyn
Seriously slinky twin that. Looks good with that tailwheel UC too - vaguely recollect that the oily version had a trike, but could be wrong. The paint job is awesome - I've have kept quiet and claimed I did it ;)! Except my club buddies know I can't paint for squat.

Your motor choice is interesting - I have one of them in my present Piper Cub - Sig 1/6th scale clipwing. Very handy and powerful, very quiet running too. Mine might be a different wind to yours, but it's an impressive motor.

Where's your batteries - fus or nacelle? I really have to do a twin, might pin your photos on a virtual notice board somewhere for inspiration.

Thank you for sharing

Regards

Dereck

[Robyn_r]

Hi Dereck,

Thanks for the props! (sic)

I took it out last night to the local club hosting the Mid-Am this year for a pre-contest wringout. I turned the sticks over to my flight instructor, one of the pioneers of electric flight. He did all sorts of fun things with it in the air including snap rolls, slow 4-point rolls, loops, hammer-head turns and of course big gorgeous loops!

I got another flight in myself but dorked the landing (too far out) and broke a prop. All good after new prop. Will fly it again this weekend.

Motors are 22/45/3, 1000KV (not the e model) and yes, very smooth and quiet. At full song it does sound really neat though. The batteries are right in the nacelles, snuggled back against the LE, right where the fuel tanks used to be. UC is very springy and yes, various people have commented that the Duelist was nose-wheel.

Let me know if you want any full-resolution pics and I can email them to you.

Robyn

[MustangAce17]

We have the arf on the wall here,it's tempting me badly,even have the retracts already

[arcticflyer]

Well guys I'm gonna do it..........scored an original Duelist kit the other day and I am going to convert it to ELEC:D

Robyn's plane is fantastic!! I hope mine turns out half as nice. I'm going to stick with the trike gear and air retracts. Still not sure where to put the batteries as I am concerned about the final balance....:eek:

If there is one thing I HATE:mad: it is adding weight to a finished plane in order to get it to balance. I'd rather put the servos in the tail now rather than add lead later.

Any advice is well taken and accepted;) Skip

[balsadust1]

Hi owned a duelist in the 70's and it and all others I have seen were for 40's IC mine had twin 45's and while quick not unmangable. I'm getting ready to convert several models myself is am very interested in this adventure some vid. would be nice good flying Les

[arcticflyer]

I now have both wing halves done and after some sanding will be joining them. The CONVERSION part will come when mounting the engines. I plan on extending the firewall forward some to get more room in the battery compartment (where the fuel tanks would be). ESC's in each wing will be under the batteries in a seperate compartment. COOLING....will be an issue for the batteries and the ESC's which will be delt with when I get to that point!
This is going to be fun!