Fast Eddie1

I am building a Thunder Tiger e Hawk 1400 electric sailplane. The kit came with a 380 brushed motor but I would like to upgrade to a brushless, run by Li Poly batteries to save weight. Any recomendations? Motor type and size, Speed control, prop size, receiver (JR 8103tx) Thanks Ed

Dr Kiwi

Your 380 with prop etc is going to weigh about 100g. For only 60g you can fit an AXI 2212/34 and get ~20oz thrust from a 10x4.7, on 3s Lipoly, at a current draw (7.7A) still below the rated max of 8A. A Phoenix 10P ESC will allow you to set the LVC at the safe 9v. A Berg 4-channel Rx with positive shift for your JR Tx would be ideal. 3s TP 2100 (130g) will give you more than enough battery [3s 1200 E-tec [84g] might be enough though they are rated for only 6C (7.2A max)]. But both of those sure beat 8-cell KAN 950's (185g). Actually 3s2p Kokam 640SHC would be really good and weigh only 60g! [and they'd give you 8A at only 12.5C and they are rated at 20C]. You could even go to 3s3p Kokam 1080SHC and still only have 90g of batteries on board.

Cheers, Phil

Of course there are any number of other B/L combos which would work too - Nippy Black, PJS and Rotex outrunners; MP Jet, Razor, Himaxx, Astro, Hacker in-runners with gearboxes.

Fast Eddie1

Thanks Phil
This is exactly what I was looking for. I would like to increase the loft time while buying good components that I could use again in a future model. Do you have any preference on brushless motors. I sure like the Hacker motors.
Ed

Dr Kiwi

I am rapidly becoming a fan of the out-runners - no gearbox hassles or noises, no pinions to slip, no gears to strip! These neat little AXI 22xx/xx's are fantastic and with 3 winds available in each size you can select the right battery and prop for your particular needs very easily.

Here's a photo or three to tempt you! AXI 2208/34 in Stevens Aero ply mount, and comparison with AXI 2808/20

Cheers, Phil

Fast Eddie1

I looked at the AXI out-runners and they do look great. I measured the nose cone area and they will fit in diameter but the way they are wired I am not sure there is room to run the wires. Can you get these wired for rear egress?
What do you think of the small 1215/16 mini AXI and a Pixie 10 esc ?
Thanks Ed

Dr Kiwi

You can turn those AXI's around by using the radial adapter: http://www.aircraft-world.com/shopexd.asp?id=1971

The Mini AC would work but you CANNOT, CANNOT, CANNOT use a brushed ESC (Pixie 10) on a brushless motor. In any case you would need a bigger ESC (Phoenix 25P) since that 1215/16 could well pull 12A-15A. If you get the AXI 2208 or 2212 you'll need the Phoenix or other BRUSHLESS ESC.

Cheers, Phil