Motors burning

[mogmog]

I'm something of a newbie to all this....

I'm running a Marui Ninja on an 8.4V cell pack (given as an option in the manual).  Having spent a number of months getting the thing together, on pretty much the first outing the motor burnt out.

I had a spare, so straight swap & on the next outing, after about 15minutes of heavy going, the motor was starting to smoke...

I was wondering whether a 3700mah pack was enabling runtimes in excess of the duty cycle of the motor- maybe it needs to cool down after 10 mins or so?  When the car was made, cell packs were typically 1700mah, so runtimes were less...?

Without going mad on an motor, what are the options?  I'm running an MTroniks Viper Eco20 esc & would rather not have to change this, or would not want to top £30 or so if I had to.

Related to this, can anyone explain, or point me to a guide that explains motor Turns & other terms etc?  many thanks

Jonathan

[mymonsterbeetleisbroken]

Hi mogmog and welcome

i'm not sure whats causing the burning motor, other than the motor may not be able to take 8.4 volts? I dont know much about the Ninja, if they do use 8.4 volts as standard then something else must be cuasing the problem.

With regards to the motor terms -

Turns means torque.

the more "turns" a motor has, the more torque it will have. But, more turns also means less speed (lower rpm)

less turns means less torque, but the lower the turns, the faster the motor will be.

eg, a 23 turn motor will have more toqrue than an 11 turn motor, but the 11 turn motor will be much faster.

[DJTheo]

What motor did you use, maybe it was just too old or oily or overgeared?

Cheers

[mogmog]

Thanks monsterbeetle,

8.4v or 7.2v are shown as ok in the manual, so

I guess that either the motors (both would appear to be original '80s

ones) are just past it, possibly combined with the extended runtime

offered by the 3700mAh pack. 

Thanks for the info about "turns"- I

think that for my purposes, an off-road buggy would want a motor with

more torque, than a revvy high speed beastie.

DJTheo,

Can't imagine the motor is too oily...as I haven't oiled it-maybe I should have done. The whole thing looks standard to me(both Mabuchi motors -nothing to write home about as far as aware), so shouldn't be overgeared - that just leaves the motor being past it - two opinions leading to the same conclusion is good enough for me.

Thanks

Jono