hi

i am using this combination on my piper j3

motor

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15185

ESC

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2168


i use my 1300mah 20C 11.1 lipo battery with it.. but it discharged in mere 3 minutes.. do u hve to use a 4 cell batt for this.. kindly suggest


regards
sujith

you can use more "MAH" battery

or u can also use 1300mah with more C rating for more flight time

A higher C rating won't increase flight time.Get a battery with more capacity.But a heavier battery will affect your CG.

Quote from: iamahuman on April 26, 2011, 07:11:22 PM
A higher C rating won't increase flight time.Get a battery with more capacity.But a heavier battery will affect your CG.

bro then how to increase the flight time?

A battery with more capacity.Or a more efficient power system.Many ways.Most common is increase in capacity.

ok thanq bro!!!

The ONLY way to increase duration is MAH. C decides the max current you can pull out. The more you pull out the lesser the duration for wich it will last. 3s, 4s etc decides the terminal voltage- this can also increase capacity but it adds weight.

1000mah 20c 2s – 7.4v can drive a 74w (7.4v X 10A) motor for 1/10th of an hour.
1000mah 20c 3s – 11.1v can drive 111w (11.1v X 10A) motor for 1/10th of an hour.
So using 1000mah 3s on 74w motor will last longer than a 2s for a given RPM.

what are the specs of your piper cub ? and what prop. size do you use on it ? because I dont think using an Inrunner Brushless motor for a piper cub would work out well...

ok here u go..

Wingspan: 955mm (37.5 inch)
Length: 730mm (29 inch)
Flying Weight: 460g (18 oz)

i use an inrunner setup with 8 X 6 prop..

i used a 1800 mah 25-35 C turnigy lipo but the CG was a big problem.. so.. wanted to go with native 1300 lipo..

Just get more batteries! Get like 3-4 batteries and swap them out at the field! Just buy a few more 1300 MaH batteries!

first of all use an outrunner a simple emax fc 2822 will do the job with a 20 amp esc and 8043 prop you will get atleast 13 mins of flight time with 1300 mah lipo
...I the wrong motor you have chosen for it thats y you are not getting flight time

The most funniest part is you are using a car in-runner on a scale plane  
Just want to ask who suggested you to go for this motor

just look at the prop u used
and the KV rating
3200KV 

i wanted a combination of 18 amp setup .. never checked the specifications..lol..

ok

i hve a new motor now

http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=100_93&products_id=273&zenid=45r7122riggm1sgu5ktkmgokp6

with ESC

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2168

LIPO

20C 1300mah 11.1 3 cell


this should be OK right??

That will depend on propeller size.
Here is a link that will help you in propeller selection for this motor.

http://www.headsuprc.com/servlet/the-1529/EMAX-CF2812-Outrunner-Brushless/Detail

BTW go through RC India Gems http://www.rcindia.org/rc-india-forum/the-rc-india-gems/. There is lot motor information a basics about setup covered there so that you will be able to choose setup on your own.

yes it will be ok go for it u will get a good flight time this time go for 8043 prop

yo..

thnks akky.

will try my luck

regards
sujith