Roy Vaillancourt 1/5 scale L-19 Bird Dog electric conversion

[tenacious101010]

I am new to electrics but see so many advantages for specific aircraft, I wanted to try some larger scale aircraft. I revcently purchased an older built Roy Vaillancourt 1/5 scale Bird Dog. The plane has about a 87 inch wingspan. The plane is very detailed and was powered by a Zenoah G-23 according to the builder. He said it was a bit underpowered. I didnt get the motor with it, but did get some rescue pods and some other droppable packets for rescue work. I decided this would be a great candidate for electric power. Its a bit heavy, but I think it will be fine. I first installed a 4130 outrunner with a 5 cell lipo for power but it didnt have near enough power. I didnt have the specs for the clone motor but I assume it is close to an AXI. I now have a Monster Power 160 to go in it along with two 5 cell 5000mAh batteries for it. I hope to have the CC 80 Amp HV ESC here soon. This should be more than enough power for scale flight of this type of airplane. The scale sound from a Bird Dog was not like a Merlin in a P-51 either, so the sound is not an issue. For powerful warbirds, I still like my gas engines. I will post images the project as I go. Previously with the first electric motor and battery combo, the plane was right at 22 pounds. It will be a bit heavier, but not a lot.
Denny

[CHELLIE]

Very Nice you will need one of these Anti Spark devices with 10 cells, or when you hook up the batteries its going to sound like a shot gun going off there is some more info on the CC ESC and what value resistor to use, I will try to find that info, Take care, Chellie

http://mgm-compro.com/pdf/en-antispark-d230808.pdf




OK, It Looks like you will need to use a 1 to 2 OHM resistor for the Anti Spark Device,With 10 Cells, Larry is one of our Guru here on Wattflyers

Larry3215
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I dont think the momentary switch idea will work. The caps will discharge too soon. Plus I think your right - the arc could easily weld the switch in the ON position.

If you do the series resistor trick, Castle recommends only useing a 1 or 2 ohm resistor - nothing larger.

They actually prefer you leave it alone and use nothing, but a small resistor is ok.

Thats from the horses mouth

[tenacious101010]

Thanks so much, that is news to me but makes a lot of sense why it is a good idea. I really appreciate your help!
Thanks, Denny

[CHELLIE]

Originally Posted by tenacious101010

Thanks so much, that is news to me but makes a lot of sense why it is a good idea. I really appreciate your help!
Thanks, Denny

Hi Denny I reposted some info from Larry3215, he is one of the best of the best here on Wattflyers, Take care and have fun, Chellie

http://www.wattflyer.com/forums/show...ght=anti+spark

[Henry Sistrunk]

I fly this one on 10 cells. It does spark but I do not not use the anti spark device. So far I have had no problem.
Henry

[CHELLIE]

Wow, Nice Big Plane Henry Take care and have fun, Chellie

[Henry Sistrunk]

Thanks Chellie. High winds have stopped the fun the last few days
Henry

[BradT]

I picked up the 1/4 scale Bird Dog from a modeler's estate a couple of years ago, with the intent of converting it to e-power. Before I got around to that, I sold my house and moved to a condo with next to no space for large models, so I traded it to a buddy that I knew would get her powered and flown pretty quickly. He did a great job of getting her set up with 10S and a power 160 (I think) with a flying weight right at 22 pounds. Here's a few pics just before the successful maiden as an electric:

[tenacious101010]

BradT, sounds like the same exact specs as this plane as of now. I just finished instaling a Monster power 160 and CC 80 amp speed control. I plan on using 2 each 5000mA 5 cells in series and an 18-8 prop to start. I will need some bigger connectors to solder on the ESC, I dont have any large enough for the size of the wire. I have a bunch of other odds and ends to do before I can have it ready to fly. I also have to wait till HK has more 5000mA batteries in the USA warehouse. I will post the results as I go.
Denny

[BradT]

I really like the colour scheme and wing stores on yours, and the detailed cockpit. The one I had was the next larger version of the kit, at 108" span, but didn't include the cockpit kit and fittings for hardpoints/stores. The buddy who completed the conversion is thinking about changing the paint and markings to a 'Nam era Marines version, since he did 3 tours there as a jarhead. Even with the larger wing, he thinks it's a little heavy for real scale fight at 22 lbs., so try to keep the weight down as much as possible during your rebuild to E-power.
Brad

[tenacious101010]

Theres not much I can do about decreasing weight without gutting details in the cockpit. That wouldnt save much weight anyway. I am adding very little and removing some to make the conversion. I will have to fly this one as-is. With the smaller electric motor I had in it before, The CG came oput perfect, by removing some of the lead shot in the nose, it will be very close with this bigger motor. For a 108 inch wingspan scale plane, 22 isnt so bad. My 100 inch BT-13 weighed 34 pounds and flew great. It even landed at a nice slow speed. I suppose it depends on what one is used to flying. I will do a final weighing of this one when I am done, maybe after the first flight so it doesnt scare me I am now wondering if I am over powering this time with the power 160. Before I purchased it, the plane had a Zenoah G-26 and the previous owner told me he thought the plane needed a G-38 to fly better. I believe the power 160 and the G-38 are roughly equivelent. I have a 106 inch Bud Nosen Citabria that flies great with a G-38, I should weigh it for comparison purposes.
Denny

[tenacious101010]

This Monster power 160 sure looks big in this plane, I hope am not drasticly overpowering it. I have only one battery so I will have to wait till I get another one to do some testing and have an idea if this is a good motor for this plane.
Denny

[CHELLIE]

Originally Posted by tenacious101010

This Monster power 160 sure looks big in this plane, I hope am not drasticly overpowering it. I have only one battery so I will have to wait till I get another one to do some testing and have an idea if this is a good motor for this plane.
Denny

if the motor will fit into the cowel, its perfect best to be a little over powered than under powered, just throttle back a little if its to much power, YEA, MORE POWER you can never have to much power

[tenacious101010]

Nope, nothing at all wrong with excess power. My concern is prop size/clearance and having to redo the firewall and engine mounting if the CG is now too far forward with this configuration. I would have to do a major rebuild of the firewall and engine mounting if the CG is too far forward to be able to move the batteries back at all. I should be able to run a 20 inch prop, but any larger may be an issue. If its drastically overpowered, I would rather have less weight and buy a smaller motor if needed.
Denny