SIG Super Chipmunk Kit c-19

[John Harman]

I have started to build this kit and would like to convert it to electric.
Has anyone done this and would offer some assistance please.
I intend using a scorpion 3020-890kv motor with a Castle 50A ESC and a Hubin timer.
Any mods to the build in general would be greatly appreciated.

Thanks in advance

John H from Brisbane Australia

[Dan McEntee]

   I can't help you with the electronics part, but there is a letter with the mods that Dave Fitzgerald made to his Chipmunks when he was competing with them as a junior and senior.  Try this link to a SIG kit history site;
   
   https://wanderings-ds-2.jimdofree.com/sig-c-l-plan-sheets-and-instructions/

     The Chipmunk wing is a pretty good wing and will carry extra weight well, but try to avoid that any way. It's an easy wing to build and build straight. You will have to modify the nose section to get the motor to mount in the correct place, but I would try to make sure you keep the nose moment as it is. Getting the round motor center line to line up may be an issue to use the stock cowling, if you intended to do that. Building the rest of the airplane stock is not the worst thing you could do and the airplane will fly well. Your main challenge is making the motor mount modifications and batter access. I don't know of anyone else that has done thins so you may be breaking some ground here.
   Good luck with it!
  Dan McEntee
   

[Gary Dowler]

   I can't help you with the electronics part, but there is a letter with the mods that Dave Fitzgerald made to his Chipmunks when he was competing with them as a junior and senior.  Try this link to a SIG kit history site;
   
   https://wanderings-ds-2.jimdofree.com/sig-c-l-plan-sheets-and-instructions/

     The Chipmunk wing is a pretty good wing and will carry extra weight well, but try to avoid that any way. It's an easy wing to build and build straight. You will have to modify the nose section to get the motor to mount in the correct place, but I would try to make sure you keep the nose moment as it is. Getting the round motor center line to line up may be an issue to use the stock cowling, if you intended to do that. Building the rest of the airplane stock is not the worst thing you could do and the airplane will fly well. Your main challenge is making the motor mount modifications and batter access. I don't know of anyone else that has done thins so you may be breaking some ground here.
   Good luck with it!
  Dan McEntee
   

Building one myself with Dave’s exact modifications. In the paint stage now. Getting anxious.

Gary

[Curare]

I have. I ran mine with a 3542 900kv motor and 3300 4S packs. It's about all I could fit into it at the end of the day.

I did start with the stock cowling, but it takes too long to load a pack so I went for the inline 6 cowling that works better for a longer pack, and the ability to top load.

The kit wood is heavy, and after an accident building the wing I changed over to a foam wing. In the end the only bits of the kit that I used was the canopy and the wheel pants.

 It was OK, but probably could have used a tad more power.

I think I did a build thread on here ages ago about it.

[John Harman]

Thankyou Dan, Curare and Gary for your most welcome replies.
It was so good to receive them and I've been looking at the mods by Dave Fitzgerald too.
He had alot of interesting ideas which I can adapt for my electric mods, although I might use a Fuz mounted u/c instead of in the wing, which looks very weak at the centre to resist the landing impact as I haven't strengthed the balsa 'I' beam.
 
I will use the inline 6 cowling, modifying the turtle deck to fit compact batteries on top of an internal removable plate
with the elctronics fitted underneath, similar to my mod to a Brodak Oriental 'electricated' conversion I did 6 years ago
which has worked very well. On that model I 3D printed some air inlet vents too which have been excellent in reducing the motor/ESC temperatures. It can sometimes get quite hot in the summer months. Still flying after several crashes!!

Thanks again guys for your help, very much appeciated.

John H