What BL motor for eco on Thunder Power lipoly's? - RC Groups
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May 15, 2003, 12:15 PM
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What BL motor for eco on Thunder Power lipoly's?


For the past few weeks i've been figuring out what to get as far as a larger e-heli is concerned. Ive recently purchased a sport ehawk already converted but after reading tony's eco/lipo post and realizing that the pack is only ( :-)) 200 I traded my ehawk for a nicely finished eco 8 (mechs).

I bought Fitz's eco last year but it was too heavy to get the cyclic I wanted (b50 11l, 10 cp2400's--wouldnt roll fast enough). Now that these lipo's are available I think they will totally transform this little chopper into a capable machine!

We have spent the last few years choosing motors, packs and gearing to get the best power/HS for our particular flying while maximizing duration. For my old eco I only got 4:50 on 2400's but it was a fun 4:50 :-).

So heres my question:

How do we choose motors based on these new lipo's since we dont have to worry about duration?

Im pretty sure I will never fly more than 10 minutes at a time, but will possibly fly twice in 30 minutes so I imagine heat is the next biggest issue.

So lets here it, which Hacker (or anything else) for the Eco on Thunder Power lithiums? Id like lots of raw power, but does the heavier weight of a b50 xxl ruin the advantage of its extra power?

The rest of my setup will be a 401/9253, hacker 48 3p opto, ubec, futaba 9 ch pcm rx, and not sure which servos.

Many thanks,

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May 15, 2003, 12:48 PM
misskimo's Avatar
hey , find the best setup for 10 normal cells and , get it like you like it and then get the 3s4p pack and she will have the same power but since the heli weighs alot less will act way different ,
I have a ikurus 250 in my little heli and it can boost a headspeed of , my guess , 2000 rpms , the motor doesnt bog down one bit , I just walked in my room from the gym , flew for 35 minutes , but that was about 55% throttle with a headspeed of around 1300 , all I can say is , damn , 2 flights a day and now I log hours instead of minutes , thats JUST (DAMN!) cant find the right words , so my suggestion , get it like you want it with 10 cells and then put in the turbo batteries and go . Tony
May 15, 2003, 01:01 PM
Registered User

Tony--sold all my 10 cell packs :-) Ive got some 8 cell 2600's for a plane but those wont do me much good.

At anyrate, the motor options seem endless:

b50 11l--ive used it, very good, powerful, but short flight times on 10 2400's.(not an issue anymore though)....dont remember how hot it got or how it compares to the b50 18s (lighter, but less powerful?)

b50 13l--never used it, more duration, but much less power?

b50 15 l--again, even more duration less power...

b50 18s---carlos uses it and looks good in the video...maybe lighter (and less powerful) is better??

I could gear anyone of these for a solid 1800 HS, but choosing which one is best for power and cooling ........?


Theres also the mega 22-20-3 and 22-30-3 (huge pinion though 20-24 t)


ps tony how does your eco balance?
May 15, 2003, 01:20 PM
misskimo's Avatar
the lipos fit right in there , , the straps snug them good and all I do it put rubber O rings on there , balance is perfic , if is was me , I would use something smaller , because , less weight , and if the motor is geared right you will not notice the difference , plus the pinion is smaller , Im thinking about getting a lenher motor for mine , the 15 15 ser. dont know about the megas , and another thing , theres a motor coming out SOON that will be for the logo 10 that is like the actro, motor , cant tell you yet , but give it 2 weeks , so they will be lighter and put out just as much power as the B50 L , hey , dont count out the aveox , good prices on those now , I have a 1406 3y , new in the box , 2000 kv , I think , for 139 Tony
May 15, 2003, 01:45 PM
Registered User
"and another thing , theres a motor coming out SOON that will be for the logo 10 that is like the actro, motor , cant tell you yet , but give it 2 weeks , so they will be lighter and put out just as much power as the B50 L "

Care to elaborate a bit :-) Will this be available in the states or international?

Im starting to think lighter will be much better espeically since i ve already got a big esc, rx and 9253

I little digging and I found this on the 15 15:


Anyone out there running these motors in heli's? Which turn were you going to use (the chart makes it seem like many different turns are available)

May 15, 2003, 02:22 PM
Registered User
Hello Scott

Just think of the pack as a 10 cell packs, just much lighter and with more capacty.

Basically what ever preformance you got on 10 cells previous you should get better preformance for a longer period of time.

For the Eco 8 with a ligher pack I would probably go with the 50-18S with 15 tooth and trust bearings. From there are going to have lots of fun.

The Lehner 1920 16 turn looks good with a 15 tooth pinion and it is pretty light. It looks to be a good alternative to the 18s but someone needs to confirm that

Man I need a Eco 8 again

Last edited by Eco8gator; May 15, 2003 at 02:31 PM.
May 15, 2003, 08:12 PM
misskimo's Avatar
it looks like you will need a motor with a KV around 2000 . so I would get a 15 25 17 , I had a 15 15 12 in my voyager and that little boy had 20 % more power than the stock motor and with the motor and esc the weight was 100 grams less than the stock motor and esc , so it the 15 15 12 could fly that heavy voyager , than the 15 15 17 could do it as well , but the 19s are just way to big , we are talking about TOO much motor Carlo, this is a lite ECO8 , power to rate ratio dont call for a motor that big , you can acheive the same with the smaller cans , and with the lenher , the 15 30 14would compair to the hacker B50 18 L , but the only thing would be the holding AMPS and headspeed , and bigger the motor the more torque it throws out , so then again , a 19 20 11 Gerhard Zibauer in 1998 had the champingship for that year in germany , huh? thats got a KV of 2800 , so you have a choice to make own your own, Tony
May 15, 2003, 08:37 PM
Registered User

Remember with a heli you can never have too much power, just stay with in reasonable weight limits.....

I have done quite a bit of my own motor testing on the Eco 8 and that thing need a motor with power if you plan on doing any hard flying(I talked to Scott, this is what he plans on doing). High power setups call for high output motors. I put a B50-11L in my Eco 8 and it turned it into a little monster, butI do admit that the 11L was over kill and that the 18s would have been a better choice.

My other favorite was the Mega 22/20/3 with a 16 tooth pinon; it weighs around 165 grams which is very close in weight to the Lehener(1000 watts @ 30 amps) refered to in my prevous post. To me a 170 gram motor seems to be the perfect choice for the Eco. I think either of these motors(mega /3 or lehner 1920/16) would make good high preformance motors for the Eco 8.

But, I still dont disregard your recommended motor becasue with the new TP Polys the Eco(compared to past 10 cell setups) will loose around 200+ grams from just the pack so the 135 grams motor you have recommended may also be a good choice. I know for a fact that the Mega will work and from the looks of it the 1920 16 but some one needs to test out the smaller motors to see if it is really an option.

Last edited by Eco8gator; May 16, 2003 at 02:09 AM.
May 15, 2003, 09:09 PM
Registered User

Decisions, decisions....

A fellow on the ikarus bbs (erez) has also suggested a C40 10L.....its got a kv of 3000 and weighs around 175 g, I would assume it would take the stock 10t pinion (its got a 3.17 mm shaft)...

Havent placed any orders yet but would like too soon :-)

May 15, 2003, 09:52 PM
misskimo's Avatar
hey , I wonder what my ikarus 250x has , KV

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