Piper Cub

[Biffo55]

Hi Guys I am new to the Forum so Hi to you all, and thanks in advance for any assistance / advice.
I am resurrecting a 10 year old foam / plastic Piper Cub stripping out all the outmoded 27 MHz electronics receiver, battery servos landing gear etc. I have also added ailerons, as it was 3 channel operation. The new 4 servos are 9 grams and the aileron servos are hot glue stuck to the underside of each wing as centrally as I can get them. The electric components being used are actually lighter (not by a large margin) than the ones they replace the balance seems fine but I dont know exactly where to locate the Cof G is on this model. Any ideas??

[xviper]

A high wing plane like this can be balanced right side up. Start with the CG around 1/4 to 1/3 of the wing's cord (from leading edge to trailing edge) starting at the leading edge nearest the fuselage. Start nose heavy (ie, 1/4) and work back (battery position) after successive test flights.

[Biffo55]

Thanks very much VXviper appreciated!

[Biffo55]

I wonder if you can assist with this - I have an ESC - bought as a kit with motor and prop. but its confused me as there is an extra twin wire with a JT connector. Looks like a 5amp circuit switch to be mounted outside as it cant be the battery cct. surely

[Biffo55]

This!

[xviper]

Sorry, can't help you with that connector. I suggest you hook everything up without using that connector and see if it works.

[ridgerunner]

That appears to be a JST RCY connector. I know that some ESCs have, in addition to the Futaba style servo output (which carries the regulated output of the BEC to the receiver - typically 5V), an additional output that uses the JST, and this is used to power FPV components (camera and video transmitter). This extra connector typically provides the full battery voltage. You can check by powering up the main battery then measure the voltage at the JST connector.

Hope this helps!

p.s. I've attached the data sheet for the JST RCY connector (which is also commonly used to power micro helicopters).

[Biffo55]

Thankyou ridgerunner

[Biffo55]

I swapped it out for another ESC I had spare that didnt have the additional wire - Job done - till I find out exactly what it is (and I have had 2 suggestions now) I will leave it for another day. (someone else advised it may be a battery balance wire - not convinced a JST connector is used for that.