Help with tt02 motor

[earton 0]

Any help appreciated 

I have recently got back into rc cars after 20 years.

i bought a tt02 Audi Quattro rally. It’s to be used on tarmac and mown grass. It came with the sport tuned motor and I used my hobby wing 1060 with a turnigy 2s 25-30c5000 mah battery. Due to loose motor mount I stripped the pinion and upgraded to the Tamiya high speed gear set using 19t pinion and 68t Spur.

It overheated and the motor gave up. I bought an etronix 17t motor and it ran for about 10 mins overheated and expired.

can anyone help with why? It’s ball raced and everything spins smoothly, it’s geared according to the sheet that came with th high speed gear set.

 

so now I need another motor and am being encouraged to go brushless, which is fine but not if I am just going to ruin more expensive equipment. What would be a safe esc motor combo for reliable running. It’s never going to race just messing about with friends and my son. If I go brushless I was looking at a sensor Ed hobby wing combo but not sure which.

 

again any advice much appreciated 

[DeadMeat666 1675]

It sounds like more information is needed to make a proper diagnosis, but I'll take a crack at it anyway:

Are you sure that everything is spinning smoothly even when the suspension is compressed, meaning when the car is fully loaded and sitting on the tarmac? I'm suspecting that maybe the dogbones are binding when the car is running, but when you lift it up to check, it all spins smoothly in the air.

[howaboutme 247]

Yeah, agree w/ the above. The commonality is that both times the motor burned up so then motor is working too hard. I would definitely check for binding throughout the drivetrain. Start w/ the mesh between pinion and spur. If you're using the enclosed spur, make sure your pinion is 0.06 mod, which is not 48p.

[earton 0]

Thanks for taking the time to answer

as per your suggestion I have checked if it runs smoothly with the suspension compressed, and to me it appears to be the same, runs smoothly. Just by compressing with hands and getting someone to spin it, is that the best way? Any advice on the best way to check for binding would be great.

pinion is 19t  Tamiya av p/n 50355 Spur is the one that came with the high speed gear set.

with the mesh between pinion and spur, I thought it was pre set? I have the standard motor mount and just choose the hole corresponding to the pinion?

thanks again for your time

[Otis311 196]

The gear mesh is set by choosing the correct holes like you mentioned. The only issue that could arise is installing the motor mount backwards as it is two sided.

Other than that the motors my have burned up because it is geared too high. The Sport tuned probably barely handled it but the 17 turn motor had no chance.

You also mentioned running it on grass. That would really make things heat up.

[DeadMeat666 1675]

There is another issue that could arise with the gear mesh. With the high speed spur, the 19 tooth pinion is no longer meant to have the motor placed in the mount hole that you were previously using for this pinion. Check the little leaflet that came with it or in most cases, your manual.

[earton 0]

Thanks for the reply, I’ll have a look. What’s the advised gearing for that type of running?


Using the above I thought I was gearing it at 9.31-1. Is that no good? I am not bothered too much about blistering performance at this stage, more reliability. I found the problem was as suggested gear mesh, user error! Would still like to know a safe ratio as I think the mesh was only the cause of the second motor overheating.

thanks again for any suggestions, certainly helped me find the mesh issue

[Otis311 196]

That ratio would be fine with a 27 turn motor. You could probably run a larger pinion if you were just driving on the road.