View Full Version : E-flight for DR1

David Olsen
02-23-2006, 05:30 AM
I'm thinking of getting into electric flight. I have a VK DR1 Triplane that I have been flying for a few years using the Laser 70 4-stroke IC engine. I have to admit, after doing research into electric flight , that I am about as confused as I can be regarding what sized motor, bat. pack, ESC, etc. I should use for this plane. If any of you would be willing to help me out with suggestions regarding a setup, I would be eternally grateful. Specs on the plane are:

47" w.s.
707.25" wing area
5.25 lbs wt (empty)

Thanks in advance for any suggestions

Don Sims
02-23-2006, 11:16 AM
Hey David, welcome to WF. I'm dropping this thread over in warplanes where we have a bunch of hardcore guys who should be able to offer some suggestions. Another option is to call or e-mail the folks at Hobby-lobby. They offer a conversion service using their products.

02-23-2006, 06:13 PM
He is right. Hobby lobby will email the proposed setup to you if you go to their website and enter the information they ask for. Steve.

02-23-2006, 08:17 PM
Whatever HL recommends, I'd toss in that it probably should be powered by an outrunner--for simplicity, added necessary nose weight, and efficiency.
I would think something like an AXI 2826/10 on 10 cells or 3S2P lipo would be sufficient for a ~5-6 lb. airframe.

You might prefer to stick to NiMH cells for the added ballast they would provide in the nose for getting your C of G right.


Don Sims
02-23-2006, 09:33 PM
Rick has a good point, you may need those NiMH cells which cost a lot less than the Lipos for that CG.

02-23-2006, 10:01 PM
David, the best place to start when trying to figure the equivalent e setup is to work backwards from your current glow setup using common parameters between the two...

i..e prop size and overall weight.

you know that it flies on your setup, right?

so you need to find a setup that will give you around the same rpm for the same prop and come in at around the same overall weight.

I'd suggest starting with looking at motors to swing your sized prop and rpm.... then from there you can figure current etc.

post it all here if you want assistance...happy to help.


02-24-2006, 01:15 AM
I would suggest you try MotoCalc http://www.motocalc.com/ for a month (free for 1 month), and this program will help you select a power system. The other way is to assume that you need 60 - 70 watts per pound of complete model. So if you project your model's finished weight at 7.25 pounds, you need about 7.25 x 70 = 507 watts. Then select a power system that can deliver 500 watts. Havew a look at MotoCalc though, it is free for one month and is a great help in deciding what combination of batter/motor/prop you will need.