Plz help selecting flight package.

[tommyt]

Hi,

I am going to pick up my new RC Guys 1/4 scale Super Decathlon this morning. :D I will be using it for Aerotow.

I downloaded Motocalc but it seems they do not list any of the giant scale motors like the AXI 5345 swinging a 22 to 24 inch prop. I figure I would like to see around 28 lbs of thrust.

Originally my intentions were to use a 50cc gasser in this airplane. But I am seriously considering going with a large outrunner and a123 cells. This will be my third Electric.

The Decathlon without engine and tank probably weighs around 12 lbs. It has a 98" wing span and 1558 sq.in. symmetrical airfoil wing.

I will also be hanging 10 to 18 lbs of sailplane on her as well. This would bring the total weight up to a max. of 30 lbs without the motor, esc and batteries.

I would like to get 3 to 4 tows at full throttle at 30 to 45 degrees lasting maybe 1 to 1.5 minutes. I would then release the sailplane and land using minimal power.

What motor, esc and no. of a123 cells do you recommend to give me around 28 lbs of thrust?

Thanks,
Tom

[blucor basher]

You are kind of venturing into the unknown a bit here with towing requirement, but a good starting point would be 14S 3p A123, 90+A esc, Hacker A60-18L,

[staggerwing]

I'm a proponent of giant scale EP however for this application gas would seem much less expensive while being more practical & predictable.
(like a G62)
Bob

[tommyt]

Yes, gas would seem much more practical.

There are quite a few Europeans however that are now using electric tow planes with large outrunner and inrunner motors with gearboxes.

My main concern with this airplane and a 50cc gasser is vibration and aesthetics.

Electric is so nice. No vibration, nothing sticking out of the cowl and no cleanup. :) Haven't whacked a finger or drawn blood on my electrics either :eek:

I want to keep the cost down by using a mid priced outrunner and the a123 cells. Figure $250 motor, $200 esc, $300 15s2p a123 or $750 fo the setup and about the same as a good 50cc motor.

Please keep the suggestions coming.

BTW, I just unpacked the Decathlon and it is very, very nice... :D

Tom

[Bill Hawthorne]

Hi Tom
You might find some useful information in the following:

http://www.rcgroups.com/forums/showthread.php?t=140475
http://www.rcgroups.com/forums/showthread.php?t=257227

Bill