crewchief_432

will a 3 cell 860 mah thunder power lipoly run a gws d gearing 300 motor with a 11x4.7 prop, and a 20 amp castel creations speedcontroller without burning up the battaries. also how do you figure out what the current draw is on these lipolys.the 860 is a 6c what does that mean? thanks for any help.

pgitta

My Feedback: (3)

That setup will draw around 7A at full throttle. I think the batteries should be OK to 3A continuous, but full throttle all the time will probably cause problems.

What I really hate about Lithium. Takes a week to charge and a two weeks to discharge. I have yet to see a real advantage to them except for a little weight benefit.

loading

6c means it will handle 6 time your capacity, which is 860 mah. So you can handle 6 x 860 = 5160 ma (miliamperes) or about 5.2 amps. I would guess that you would be pulling over 12 amps with your setup. I think you may need to get bigger batteries.

crewchief_432

thanks for the quick reply guys. do you think a 1200 thunder power would work. im trying to keep the plane lite with the set up it has now it weighs 7.4 oz.the wing span is only 28 inches.looks like i need to break down and go brushless.thanks again.

loading

Wow, that is lite. I see why you are trying to keep your pack small. It sounds like you are going for some vertical performance. Brushless would be the answer if you can afford it, but you still need to be able to feed it the amps. pgitta thought it would only draw 7 amps, so maybe I am a little high. GWS lists 6.4 amps with this setup on and 8.4 volts, you will be at 11.1 volts.

pgitta

My Feedback: (3)

I guessed around 7A because of the low prop pitch, but I admit it could be more.

6C Lithiums? Constant current? Are we sure that's not bursts?

Plus, I forgot. With three cells, that 300 motor will have the lifespan of your typical housefly.

jonnyjetprop

My Feedback: (3)

A 3 cell (11.1 volt) pack may be too much voltage for you setup. I used a 3 cell 1200 mah etec pack in a Mountain Models Tantrum using the GWS 300 motor and the D gearing. The motor lasted two flights. I went brushless and have never loked back. A club member uses 3 cell packs with good luck, but he is very careful to throttle back ASAP after takeoff.

John Pursell

crewchief_432

thanks guys i think im going to get a brushless.what battery motor esc set up do you all recommend for the gws d gearbox.

loading

I have the Himax 2015-4100 in my Formosa. With a 10x6 GWS prop, it draws 8 amps static. It has unlimited vertical and would probably hover somewhere between 3/4 and 1/2 throttle. I can't hover so I don't know for sure. The Razor brushless motors weigh less, but they are really hard to find. If you went with something like the Tanic 850 pack, and the Castle Creations Pheonix, you would have a rocket. I think my Formosa weighs about 14 oz, at 7.4 oz I can't even imagine it.

Dr Kiwi

Why not forget the gearbox and get an AXI 2208 or 2212. Check out the threads on these in RC Groups. You can easily get 20oz thrust at <8A from a 2212/34 on 3s with a 10x4.7 - mount it in a Stevens Aero ply mount and it will weigh only 85g complete with adapter and prop, and a Phoenix 10 ESC. Use 3s2p Kokam 680SHC and your battery will only add 60g.

Cheers, Phil

crewchief_432

thanks for the replys. i kinda wanted to stay with the geared motor so i don't damage the motor shaft when not if i dumb thumb the plane in to the ground.thanks again.