MischMaster 1 Posted February 21, 2021 Hi, last year I've already wondered why the motor looses the power cables. I expected because of crashes. But today I lost both without a crash. I have the feeling that the motor gets so got, that the solder gets weak. Maybe I exaggerated the gearing and/or motor. I can not touch it longer than 1-2 sec. I have a 19T brushed motor with 19/68T gearing. Is that too much? Would a fan help or do I have to change the gearing? If yes, to what? Thanks, Michael & son Share this post Link to post Share on other sites
Jonathon Gillham 4595 Posted February 21, 2021 I've heard of that happening but never had it happen to me. That gearing will be far too high for a 19T motor. Its probably so high that its slowing the car down as the motor won't be able to get to its max revs. I found a stock TT02B with the kit torque tuned motor was sluggish with a 19T pinion and went back to the kit supplied 17T. Try goijg back to the kit spur and pinion and see if it still overheats, and whether it is faster Share this post Link to post Share on other sites
MischMaster 1 Posted February 21, 2021 Uhhh.. ok. Is stock 22/70T? Share this post Link to post Share on other sites
Jonathon Gillham 4595 Posted February 21, 2021 Stock for the TT02B is 17T / 70T, FDR 10.71 Share this post Link to post Share on other sites
Boomstick 156 Posted February 24, 2021 Used to happen to me back in the day of 20+ tooth pinions and 16 turn single motors with 9.6v double hump packs in my original blackfoot, king cab, jrxt and rc10t. I drilled a larger hole through the tab on the motor and used a crimped on ring connector with a screw through it to screw the wires to the motor. Then I started popping the solder drop fuse on my speed control (novak 410 iirc) so I just wrapped the two little tabs with copper wire... I burned up 2 jrxt's and a rc10t doing that... Share this post Link to post Share on other sites
ewant81 33 Posted February 24, 2021 Out of curiosity, is your car running a full set of bearings, or the mix of plastic/metal bushes? If your running a more powerful motor, you really should switch to ball bearings everywhere. The additional friction of bushes will increase the motor temp. Share this post Link to post Share on other sites
MischMaster 1 Posted February 25, 2021 No, I have bearings from the beginning. I ordered a new 70t spur gear and I still have my 17t pinion wheel. So I switch back die 17/70T like Jonaton suggested and see if that solves the problem. Share this post Link to post Share on other sites
Tamiya Fan 1 114 Posted February 26, 2021 Your motor is getting way to hot!! They should never run this hot. Gearing could be the problem. You can go about 3 sizes up or down with the pinion from stock to be safe. I don't know what the original sizes are. Is everything moving freely? Rusty bearings that need oil? Motors get warm to hot but not scorching. Should try to find it because you will fry your motor if not all ready. Hope this is some help. Share this post Link to post Share on other sites
c64orinoco 667 Posted February 26, 2021 If the motor was getting hot enough to melt solder, the internal coils on the motor would come apart - they are soldered to the bushings. It looks more like a 'dry' solder joint that hasn't connected properly and vibrations have caused it to fail. Share this post Link to post Share on other sites
lentner3 281 Posted March 5, 2021 I would be double checking the solder joint . Also you could have already shorted out some of the windings by overheating it thus exacerbating the problem. As above I would clean up the contacts resolder properly and look at adjusting the gearing. heat sink and/or fan wouldn’t hurt either. I suspect there is more to the story though as with that kind of temperature I would expect the motor to be smoking. Share this post Link to post Share on other sites