2 planes differnt battery voltages
 

Ok so heres my situation

i wanted to get into the world of RC planes,,, (iv had cars boats and helis) and after my glow powered heli (Raptor 50) and my electric heli / car i decided that i wanted an electric plane
so i researched a bit and i was also looking for a cool plane, Iv always loved the J3 Cubs. so what do i do ? i buy a Eflite J3 Cub 25 with all the recommended stuff including the 175$ Lipo .....

and iv been trying to fly that and A) its not a trainer B) i don't know how to fly C) the place i'm flying isn't the best for tail dragers

so rather then try to hand launch my plane and maybe have it crash really bad and then i have no plane at all
i figure the best thing to do is buy a electric trainer of similar size and learn to fly with that... leaving the cub on the shelf till im good enough for it..

so i realize i'm gunna have to cough up at least another 300-500 $ to get a good trainer.

iv been looking at the Hobbico Electristar Select..... it looks to be a good plane BUT it takes two 7-cell 8.4v 3000 mAh NiMH or two 7.4v 3200mAh 20C Li-Po

so this 7.4 V is what is the problem


as i bought 11.1 V batteries for my cub and i already have 11.1 v batteries for my heli and of course 7.2 V for car/ boat
i don't really want to bring another battery voltage into the family.. Ideally the future trainer should use the same battery's as my cub

eg the stock Nimh 1800mAh 12V 4/5A or the upgraded Li-Po 3850mAh eXtreme 11.1V both of which i have

now charger's isnt a problem as a while back i figured the best thing for me would be a Triton charger becuase it does eveything...

so my question to you people is :

what trainer preferably RTF or ARF is there that takes 11.1 V batteries.....

Any info is greatly appreciated

RE: 2 planes differnt battery voltages
 

It sounds like the simple solution would be to build or buy a .25-size trainer like the Phoenix Sonic low wing ARF, the Sig Kadet LT-25 kit, the Goldberg Freedom 20 kit, or the Great Planes PT-20 Kit and then outfit it with the same E-Flight Power 25 brushless motor and ESC that your Cub came with.

You'll be able to train with the same power setup and fly it with the same battery that you already own.

RE: 2 planes differnt battery voltages
 

Goldberg Eagle 400 will run on your 3s lipo. And it is a good trainer as well.
http://www3.towerhobbies.com/cgi-bin...?&I=LXHCE9&P=0

RE: 2 planes differnt battery voltages
 

ok so i must be stupid or somthing but what is the reason for having TWO 7.4 v batteries lipo or not vs ONE 11.1 v.....

is the motor i use in the cub like smaller then the electristar ?

so 7.4 times 2 would be 14.8 V...... or just double amprage ???

if i got the same motor / esc in the cub and put it into the electristar would that be a suitable match ? reason being iv heard ALOT of good things about that plane ....

srry for being so dumb lol

RE: 2 planes differnt battery voltages
 

Sunfm
The batteries in the electristar are wired in series making it 14.8 V lipoly, or 16.8V Nimh
you would need a 3200 4S pack to fly it on one lithium pack.

RE: 2 planes differnt battery voltages
 

No the Power 25 motor is not enough for the electristar. You would need something like the Power 46.
and a 60 amp ESC, which would require the same battery as the electristar. 14.8 3200 4S.

The power setup you have now would probably work great in an E-flite ultra stick 25. with the
throws toned down you could use that plane as a trainer.

RE: 2 planes differnt battery voltages
 

Sorry, I accidentally typed "Sonic Low Wing" in my previous post when I actually meant the Phoenix Sonic high wing ARF:

http://www3.towerhobbies.com/cgi-bin...&I=LXEDN6&P=ML

I would think that this would be a nice ARF for a brushless conversion.

RE: 2 planes differnt battery voltages
 

ok so that all makes sence

well thanks alot for the info

i think i better stick with a RTF becuase im just learning and i already screwed up building my ARF cub.... (damm ca hinges)

thanks for all the info .. more is good too

and i think probebly go for the electristar or the nexstar select EP....

and ill make the cub my "second" plane and leave it on the shelf till im good enough for it becuse its such a nice plane :) and i dont want to break it

RE: 2 planes differnt battery voltages
 

Sounds like a good plan. The Electristar is nice and probably a better value than the Nexstar EP in my opinion. With the Nexstar EP, you'll be paying for wing pods, airbrakes, and an Auto Levelling System that doesn't work.

You'll end up with some additional batteries in the family, but it would be much easier to buy the Electristar RTF than to put together your own electric trainer designed to run the same battery.

Good luck and good shopping!

RE: 2 planes differnt battery voltages
 

yeah i defintally think a rtf trainer is better then trying to cobble one together ....

and the Nexstar vs electristar ? this isnt the time or place but iv heard good reviews of the Nexstar....and for $100 more...... it might be worth it

RE: 2 planes differnt battery voltages
 

I would also, the electristar requires a charger, 2 multi cell batteries ([sm=greedy.gif][sm=greedy.gif]), and if you want to fly acro, you need like 2 4 s lipos ([sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif][sm=greedy.gif]), I would go nitro, and if you get sick and tired of it, you can sell the engine... and get a brushless system[8D]

RE: 2 planes differnt battery voltages
 

if you would go glow there are lots of options but if you like the electristar I think the glow version is the avistar but im not sure. I here the LT 40 if im correct is a great trainer.

RE: 2 planes differnt battery voltages
 

True, the LT-40 is an excellent trainer - perhaps the best one out there today. It is a .40 size (or ideally a .46 size) glow trainer. Nothing wrong with that unless you don't want all the field accessories to support glow engine operation.

Sig makes an EP-42 electric version of the Kadet albeit smaller than the LT-40 and is also a taildragger. I think they also make an electric version of the LT-40 ARF/RTF.

RE: 2 planes differnt battery voltages
 

i think iv made my decision

im gunna go with ........ drum roll.....

the



ELECTRISTAR SELECT EP rtf

now all i need to do is save some money lol

thanks for all the advice

RE: 2 planes differnt battery voltages
 

Sunfm,

There is another way... by changing your prop sizes you can extract more or less amps from a plane.

The way to figure this out is start with the takeoff weight of the aircraft - 6lbs according to manual.

Factor in enough power to fly = 75w/lb would be heaps for this kind of aircraft - so 6x75W = 450w.

Now, assume the voltage based on batteries you own - 11.1v, and derive current 450/11.1 = 40A - so if you have a 3s LiPo that can deliver 40A burst (and so 30A continuous) then you can fly this bird on a 3s pack.

Now you just need to find a prop that will achieve this - 11x7 is the stock prop, so maybe going to a 12x8 as the first step. You might even need to set up to 13" (although you need to start being careful about ground clearance).

Anyway, the point is this - just cause they say you need such a such a battery voltage isn't necessarily true - by varying your props you can suit different voltages (like putting to 3s Lipos together in series would deliver 22v, meaning you would only need to draw 20A - you could probably step down to a 9x6 or maybe even an 8x6...

Get the idea?

Cheers,
oz.

RE: 2 planes differnt battery voltages
 

thats a good call too

i dunno really i kinda need to save some money first and buying presents for Christmas isnt gunna help lol but we shall see

thanks for the indepth reply