RC India

god knows what happened to my j3 piper, when i attached my 1250 mah 11.1v wolfpack, it became hot and swoll  and died in a minute, i thought sth happened to my battery and connected other battery 6 hrs later, this time zippy 1000mah 11.1v, same thing happened... what can i do ?? throw the model??? it was brand new,.. just 1 flight done...landing was not that bad.. tail crashed but got it fixed...is sth wrong with esc??? :'(

Did you check the + and - symbols on the ESC and ensure the right leads matched from the battery?

it is an rtf...we used a deans connector that worked perfectly fine the previous flight

red was with red b with b

bro .that may be u use more than minimum neede volt.9v.or there may be a bad connection problem.do u see any sparking?

check the motor to esc wire is properly insulated

I thought the same... The connectors it originally had was of 7.4 v cell but the specification given in rcbazaar for this product was 11.1v so I desoldered it and connected deans... But it has 1700kv motor and 18amp esc... What's your opinion?? I previously had a flight and that worked perfectly fine.. How can it suddenly not accept 11.1v??

it cant happen.even though there is some case.if the connectors are, ok the 3s 18a es c and 1700kv motor burned some particle of ur esc.upgrade it with 25 amp or 30a esc

Roby were you bought this????????

Both times esc beeped... Then stopped.. Usually they beep for long .. C'mon whr r the experts?? Escs not broken

Mr Moorthy I dint get yah :p

And batteries and connectors are fine... Works well with another electronics

Were you bought j3 piper cub

roby - its very difficult to understand what you are saying thats the reason
none of the experienced people have commented.


please from the beginning ... explain properly

also try and post a picture

did the two batteries swell and die immediately upon connection
or did it swell during the flight ?

first you have mentioned battery swell and died and now you type battery is fine with other electronic could you be clear :headscratch: :headscratch:

Most common cause is you exceeded the battery capacity by drawing too many amps too fast.

1700 kv motor.  What prop size did you use?

Kindly tell exactly what prop size, motor, esc and battery rating used by you. Also, although I know this is very small thing, still since two batteries died so am asking this... are you sure you soldered the T connectors(Dean connectors) properly. + and - are usually printed on the sides of connecting terminals. A pic of the whole setup would be helpful. Its really shocking and sad two batteries died simultaneously... :( :(
 :hatsoff:

look, what i meant was i was doing a workshop for my college fest, i connected wolfpack, that died...i though sths wrong with the battery, i used zippy.. that became hot..got swollen... but is still working with other electronics as of now..but i dont think that'll last long..that already looks like an airbag

did you change connector in zippy lipo? what mah zippy you used?

prop size 9 inch..motor 1700kv esc 18...have mentioned these :p

and where am i not clear? it might sound crazy.. but then u are most welcome to test it with your lipos... i'd be glad to ship it

Mr. morthy i bought it from rcbazaar..

and i dont wanna risk any more of my lipos :p i dont have many :p

i dint... but i did that with wolfpack... how does it matter anyways? it was a 1000 mah 11.1v
what i was thinking was is it because of the voltage? but in the rcb specifications 11.1v was required

check the soldering , low quality plugs usually melts from inside while soldering, jst a random thought..... :)

checked it...cant see anything wrong there... is there any way to check by suppying some dc power? don't want to end up with burned lipo again :(

Did you try using the battery with another esc? There can be short inside the esc. You can remove the heat shrink and check if anything is burnt, if you cant claim a replacement or warranty.

Or the motor can be burnt. Try to use it with different motor.

And if the second battery got swollen, so should the first battery I assume, as you have mentioned it died?
If both the batteries got swollen then the culprit is a short circuit somewhere. You have to check each item by plugging them with other esc's or motor to ascertain what the issue is exactly.

You mentioned the battery has swollen up like an airbag. If you aint exaggerating, then get rid of the battery before something goes wrong. Lipos are unstable and dangerous you never know when it lights up particularly if its damaged. Similarly expect the soldering in the dean to be perfect without any shorts.

While mentioning items please mention the make and also size of the motor, discharge rates of battery and esc's. Makes things easier.Right now how do we know whats the current your motor/esc are rated for and voltage your esc/motor is rated for?

There's your answer.  9" prop on 1700 KV on 3s Lipo.  I'm estimating burst of 40+ amps at full throttle and 275 plus watts.  Something had to give.  Either the ESC or battery will burn out.  You got lucky if your ESC survived and only the battery died.

You can put in 100 brand new 3S lipos and run them all with the same result for each.  If you insist on using the 9" then upgrade the ESC and go to at least 3000 mah 30C lipo but ecen if you do, your motor will burn out instead.

With a trainer style Cub with a flying weight of  > 500 grams, you just need about 120 watts.  Those Cubs will fly on 8 and even 7" props depending on motor KV.

 

idk y people think every other guy in this forum is a liar and a culprit..here are some pics of my ultra swollen wolfpack

but thats an rtf lance,,.. and it was supposed to be used with 11.1v..

check this out urself

http://www.rcbazaar.com/products/1437-super-j3-piper-cub-1070mm-pnp.aspx (http://www.rcbazaar.com/products/1437-super-j3-piper-cub-1070mm-pnp.aspx)
1200mah was recommended ..at 11.1 volt.. i used 1250

Out of all the questions I asked you answered one that too because you assume I called you liar while trying to ascertain how the battery looks exactly? Did you read further the warning I was trying to convey?

You have to use the "right" 3S lipo based on the amp draw.  If your setup is sucking 30 amps and 1500 mah 3s lipo rated at 20C will max out at 30 amps, you will puff the battery on the maiden flight.

A 40 C lipo will help but more important, you should prop down to a 7" prop and not just 7" but with a pitch of 3.5 and not more than 5.  

@roby
A closeup of your Deans please.
See mine.

okay :p so what can be done? how can we check if the esc's fine? or the motor? i don't wanna void warranty, if there's any

Something is wrong with your Dynam Cub specs

http://www.nitroplanes.com/60a-dy8927-j3-yellow-rtf-24ghz.html (http://www.nitroplanes.com/60a-dy8927-j3-yellow-rtf-24ghz.html)

The same Dynam in Nitroplane is a 1350 KV motor.

If you click on spare parts, the suggested replacement motor are 1200 and 1350 kv. You must prop down.

ur right...i should be using 7.4 v right? its rc bazaars fault, isn't it?

here's my dean kk sir

It looks like you have soldered the dean the wrong way. Look at Mr Iyers pic carefully.
Did you solder deans on both the batteries?

can this be possible? because i soldered it in the esc as well,,, so i am sure that red goes to red
how does it matter if i soldered it the other way in my case? and after 1 successful flight??

What about zippy ??hope zippy 1000 mah comes with 2 Pin Mini JST Plug and zippy compact comes with XT60 connector if you have used dean plug how did you connect zippy.

@roby
Sidewinder responded while i was at dinner.
Red wire on horizontal tab?

Pic of the other side connector too please.
Also pics of the connections for the successful flight.

(Don't get angry, only trying to help)

Okay, confusing. If you have made necessary changes on the esc while soldering plugs, with respect to the dean on battery, then its alright.If you reverse the polarity esc will be damaged. It can further extend to your battery. Anyways there is no way you could have flown on reverse polarity.

On further searching, most of the 20-27 size motors(you haven't told us the size of the motor or make) with 1700kv are not rated for 3s battery and most of them have 8" props suggested with 2s lipo .(first 3 results)
www.google.co.in/search?q=1700kv (http://)

So if your motor is something similar to them, then it must have given up during the first flight due to heat because of excessive amp draw/voltage, leading to a damaged esc which may have shorted and damaged your first battery. You must have been flying while all this happened so the crash. Since the esc was already shorted, the moment you plug in the second battery it heats up.

There can be many more scenarios, more info & pics will help.

Dear Member

from beginning Mr roby say he blew the battery and then he say its fine with other electronics.How come he did maiden flight perfect and next attempt this tragedy happens. No connection has been changed


Reason for asking him were you got this J3 Piper cub

http://www.rcindia.org/for-sale/super-cub-pa-18-easy-trainer-for-sale/ (http://www.rcindia.org/for-sale/super-cub-pa-18-easy-trainer-for-sale/)

he mentioned in this sale post he got J3 cub from hobbyking Australia warehouse. $80+$80 shipping and sold it for 7000 INR Hope every one who ordered from hobbyking know we can buy only from international ware house if we order from India even though we try this will be the message

Attention

You are located in IN but one or more products in your cart are from the Australia Warehouse or Store Front and cannot be shipped to your country. Remove the product from your cart and add the International warehouse item with the same SKU

same way in pic what he posted can view  (dynam) super j3 piper cub.its available in www.rcbazaar.com (http://) (http://) (http://).

Super J3 piper cub (1070mm)only available in HobbyKing AUS ware house

specification is much different between hobbyking J3 cub and dynam J3 piper cub.like motor,propeller,even flying weight


So MrRoby is not clear from beginning try to say rcbazzar made mistake.

:p Mr. moorthy i made that post to look at the potential of selling j3 cub over here, with a cut of 500 bucks/model...i bought 1 which is a 2nd hand thing... another 1 is from rcb... i have many models..2 days back bought 2 from @theleabres.. and the zippy is also his... maybe he soldered the deans... you have a grudge against me moorthy sir? Why do you want to put me down?? i'm just here to ask a query and you seem to be constantly annoying me

also the dynam is the model i'm talking about here...which is brought from rcb..my brand new j3 cub was sold.. at 2k less than what i paid

reason for blew this the way you reply to members

check all your topics its a public forum Mr roby.If we ask any doubt you reply

 


Now you post

Don't like to pull this issue.Even now you don't accept the mistake.


in sale post it say clearly brand new J3 now you reply used one.So be clear.

i'm just a kid, must apologize on my part. I'm just a bit too  curious cuz spending for a lipo was too much for me.

Roby

when i join this forum zero knowledge about rc but today learnt lot and still lot to learn.Many senior members are here to help us if we are clean and clear they won't let us down.

Go head with your doubts .       PEACE.

@roby
So finally what was the answer to why the lipos burned?

trying to post pics... took 3 screenshots..still its not less than 200kb.. what exactly you want to see?
i'll post in fb and get the links

still got to find that... i think there's sth wrong with esc or motor of dynam from rcb..or j3 cub(they look similar, call them whatever Mr.moorthy...not the hk thing but the rcb thing)
never opened it ... well i wont miss the chance to prove myself when people are stripping me for no reason

viewing to your screenshoot,i think you have soldered wrong wires,+ and - connections are changed by mistake on battery side,check it.

i have soldered both the parts of dean the other way :p so ultimately should that matter??
and i had 1 sucessfull flight as well :p :p all this i've mentioned before

its not a problem.as long as +ve connects to +ve and negative to negative there will be no problem

Something-This word doesn't hurt to type it completely.

My inference.
Those ESCs can run on both 3s and 2s and might be warm for a full throttle.
and i have overpropped a 9x5 prop instead of 7x5 on a Emax 2812 motor and it still gets a little warm after a complete run.
so over propping and battery issues are ruled out. wolfpack comes with those dean connectors readily soldered for 3s and 2s so there is no way lance got it wrong on the Lipo. either it is a faulty ESC or a short circuit or you have reversed the polarity on the ESC. and i dont see a heat shrink sleeve on the ESC soldering this might have short circuited the Lipo,
Please bother some reading instead of considering this forum as a one stop solution for all you wooes. i have used a 6 volt 3A power supply to check a ESC without prop on the motor.

Ashok.P

Bring your Cub (just the fuselage only) next time you visit.  After I check the wiring, I'll use the watt meter with a new 3S 2200 mah and the 9 X 5 prop.  Then we will know the power draw.  If it sucks out more amps than what your battery is rated for, you will swell the lipo.

A 1700 kv motor and 9 X 5 prop is an unusual combination and since I've never tried that combo myself, I'm interested in the results.

Thr is no way any short circuit could have happened bcz I told previously all these happened when I was giving a demo and that too with two lipos ., I was able to save one.. Ty v2 for ur concern, but I've tried to engage myself as much as I can with the threads..
Oh you could have pmed me that yesterday lance... Well I'll be visiting again very soon and till then I'll not open the cub.. Surely we'll have to figure out whether I missed sth or if that's a manufac defect