Wires getting so hot!

[hemy]

Hi I have a g&g combat machine, and recently upgraded the spring (m110) and the motor to a high speed g&p m120 high speed motor i believe. After installing the motor everthing was fine. But after installing the m110 it sounded real cranky like it was low battery and all the wires got real hot, then the fuse blew. Do you have any idea what was wrong? If you need any other info to help feel free to inbox me or Thanks Rhys (P.s i was using a 8.4v Ni-Cad)

[antonwardo]

Re: Wires getting so hot!

Sounds like there is too much load on the motor with the new spring. Or could something possibly be out of place when you rebuilt the gearbox?

[Ekaj]

Re: Wires getting so hot!

The motor will draw too much current trying to compress that rate of spring. A high torque motor would work better without electrical overload.

High speed motors work best with lower spring rates.

[sj_asc]

Re: Wires getting so hot!

The M120 motor draws a lot more current both unladen and particularly when under load than the CM mot0r it replaced. In order for you to get the best performance from that new motor you need to ensure it gets ths amps it wants. A highjer capacity wiring loom (16awg +) with a MOSFET will work wonders. You will also need to ensure that the battery pack is able to sustain the higher amp draw. A large type NIMH 3000mah+ as a minimum, or high discharge/capacity LIPO.
The M110 further increases the load and thus amp draw. Without a FET in this situation the switch contacts will be wearing much faster and dumping any expecte4d performance advantage in the form of waste heat.

[dave38x]

Re: Wires getting so hot!

However if you throw all of those electrical upgrades at a G&P M120 motor it will in all likelihood burst into flames because it overheats (as has happened twice when I've done exactly this and the customer hasn't wanted to install a high torque motor) - they draw far too much current for the power they put out, sell it and get a Lonex A2 or SHS High Torque!

Then there's the fact that the pinion is made of cheese...

[sj_asc]

Re: Wires getting so hot!

Providing there are no defects with the motor, and that the setup is running efficiently they should not be burning out. I am aware that the more recent batches have been hit or miss, but asides from the change of end bell colour, I cannot see updates to the new design over the old one. I guess it may be in the temperature rating of the enamel coating, or just general poor QC.
The earlier generation motors were actually pretty good for ferrous motors, in fact most people ran those for ~40rps builds over the systema purely for the sake of reliability.
As far as the pinion gear goes though, yes they are less than ideal, however should again still not be an issue for a relatively pedestrian setup.
The SHS high torque motor is essentially the G&P M120 armature in a neodymium magnet can, the magnets obviously account for the majority of the torque, and the Lonex A2 is an even faster motor, but offers less torque. They both will offer significant gains over the G&P M120, but expect battery life to still be worse than it was as they will all still draw more current than the stock motor.