I purchased an Omega electric 2-meter glider with a Promax 14 cobalt motor, Planetary gearbox of 3.7 or 4.3 using an 11/8 folder. Plane crashed due to another tx being on at the same time. Finally found another ARF that did'nt cost quite as much. Trendy 480 (480 sq."). Poly wind instead of straight. This unit wieghs 2# complete. Had to add an ounce of wieght to the tail. Am using 8 cell 600mah nicads. Is this motor combo too heavy for this bird? The Omega was not able to go out at a 45 degree angle with this set up. Hitec 555 rec. and 81 servos. 45 years of flying with gas. This method requires a lot more knowledge and there are so many combinations to choose from.. Thanks for the help.[8D]

At first glance, I think the plane should fly on that combo. Unfortunately, I don't think you're going to get the 45 degree climbouts.

600mAh NiCds will be pretty much limited to 12 Amps if you want them to hold up for more than one flight. On 8 cells the best you can expect is about 96 Watts, or slightly less than 50 Watts per pound. That 2# airplane weight is WITH the motor and battery, right?

That is correct. The 2# weight includes everything ready for launch. What battery type and pack size would you suggest? Am I better off installing a different motor? If so which one? And if brushless I would need a different controller correct? I would really enjoy a glider that would gain altitude (more than 100 feet). While we are on this subject perhaps you could suggest a different plane motor battery combo. Gliders. Thanks for the help.[8D]

30 Watts per pound is the bare minimum to make a plane fly. A sailplane will climb on 30 Watts per pound, just barely. I don't know about you, but most sailplane pilots like to get up to altitude ASAP, and if I remember correctly, you did mention 45 degree climbs in one of your posts somewhere.

That Promax 4014 Cobalt is a pretty hot motor, and should be plenty to fly a 2# glider on 8 cells.

I'm runing the numbers on http://brantuas.com/ezcalc/dma.asp, and your setup looks pretty anemic. You're only drawing 10.7 Amps according to the calculations on the 3.7:1 ratio with the 11x8 prop.

We can work with this!!!

Just like a glow engine, electric power systems can be tuned, and usually need it. There's no need to start fresh each time you have a "failure." One amazing thing about electric motors is that you can get them to make more power by simply increasing the size of the propeller. Go to a 12x8 prop, and you increase static thrust by 20%, from 25 oz to 29 oz. That's pretty close to 1:1 thrust to weight; the plane should climb at a steep angle. Amps are up to 12.8, which is fine if you don't run the motor at full bore for the duration of the pack.

Wing loading is right around 10 ounces per square foot, which is not bad at all. This plane should fly great. If it doesn't, you might have other issues, most likely an undercharged battery. Have you got a peak charger?

Matt Kirsch

First let me thank you for taking the time to answer my questions about this combination. I know you have a million and one people asking for answers. Not being long in the electric end of this hobby I have much to learn and it is hard to do this when you fly along. I will try to locate a source for 12.8 props that fit a 1/8





Matt Kirsch:

First of all let me thank you for taking the time to help me with my question. I realize there are thousands of questions flying at you. It is hard for an electric novice to learn much when He flys along. I will try to find a source for an 12.8 folding prop with a 1/8"shaft. lloyd

You may need to pick up a "prop adapter." Hobby Lobby sells a wide selection of them. Prop adapters grab on to the smaller shaft with a collet or set screw. They're larger in diameter and threaded like a glow engine's crankshaft.

Thanks again. I found new blades at New Creations R/C. They will fit my hub.