SOTA With The Vanquish: My Little Truck Climbed Peaked Mountain (W1/CR-006)

Ok he didn’t. He just happened to be driving the little truck, full throttle, trying to dislodge it from a pile of leaves, mud, and sticks, so he could get back to attempting to crawl it up a log. Like every grown up does. And when he finally reached down to rescue the truck from its entanglement, he realized that the wheels were not turning despite the squealing motor.

I carried the poor little fallen soldier all the way back to the car.

Fortunately we had made it to the summit of the tiny little Peaked Mountain. Our Summits-On-The-Air activation was a success. Our attempt to use our newly acquired bothy bag once the rain came, and this time with a giant rather unruly dog, was not. We stopped our activation after eight contacts, packed up, and began our one mile descent.

I let AA1F drive my little truck on the way down. He only made it halfway before the wheels stopped moving.

The nicest part about RC vehicles is that they are rather simple. Running through a quick mental checklist, and I knew it had to involve the transmission gears. The battery had enough juice, when one wheel was manually turned the other three wheels turned with it, and the motor revved as if it were working when the throttle was depressed. There was no power getting transferred to the wheels from the motor.

Sure enough, when I took the transmission and motor out, I could see that the motor was running and turning the motor shaft along with it. The motor shaft however was not turning the pinion gear that was sitting on it. The shaft simply was not engaging the pinion gear at all. Ta Dah! Turns out the set screw on the pinion gear had come loose.

This RC garage event gave me a chance to reposition the pinion gear more squarely on its big brother, the spur gear. I have been suspicious that I misaligned the two during the build. And I also wondered if I had previously placed the set screw incorrectly on the rounded side of the motor shaft rather than the flat side, and perhaps that is why it came loose. I tightened down the set screw choosing again not to use threadlock for better or worse, rebuilt the truck, and tested it out. Works fine although it sounds a little different (and not necessarily worse).

My assessment? AA1F had nothing to do with the transmission failure, only timing. He’s off the hook! Poor guy vowed never to touch the little truck again…that is until I handed him the controller and he couldn’t resist…

In summary, this was the little truck’s first SOTA! It mostly did great up until it died. It is a lot of fun and I expect to take it on more adventures despite the funny looks I get from some people I meet out on the trail. Not only is it a bit of a relaxing, childlike amusement to play with an RC car, it is greatly satisfying to fix it when it inevitably breaks. I would highly suggest building a kit for anyone wanting to get into radio control, for the simple fact that it is easy to visualize what is wrong with the vehicle when it stops working.

Who knows where these paths lead?

KM1NDY