My Wheely King RC toy was a tad fast for crawling over obstacles and also lacked torque and endurance with the stock motor and batteries. Simple fix: I cooked up a cheap brushless motor setup.

Ingredients:

• one cheap Chinese 2830 outrunner (850KV, 58g, 3.17mm shaft): $20 with shipping
• one fairly cheap Chinese/German ESC (speed controller) for brushless motors, $35 plus $15 shipping
• smaller pinion gears, 12, 13, 14, 16 and 17 teeth: $20 plus $10 postage
• some time for filing down the motor mount: dusty but free

Install the 14 tooth pinion. Mix and stir well. Season with absolutely incomprehensible Chinglish instructions for the ESC. Simmer on "Medium Angry" for a week. Find the German partner company who's responsible for the design of the ESC, and who has a manual in Real English. Turn off the heat, install, enjoy the slooooow speed at full blast. Up the pinion teeth, to 16. Reinstall, enjoy both the torque and fast-walking speed on full throttle. Mounting the brushless dwarf was interesting, because it doesn't have the same screw pattern as the big 540-size original motor. It comes with a converter plate but using that the shaft is too short. So I made do with the smaller screw spacing. I simply filed away a fair bit of the motor mounting plate and then used a drilled steel washer as counter-piece for fastening the motor.

Getting the ESC to stop beeping and start working was almost as horrible as having to learn vi without a clue and a manual (ie. it beeps a lot but doesn't work, no matter what you do). Extremely frustrating. The thing being a very no-name non-brand, I even cut off the heatshrink to have a peek at the circuit board looking for manufacturer clues, but to no avail. Eventually and only because of a few really odd, happy circumstances I finally found out that it's one of these and got a working manual. Wohee, this actually works! I glued on an old heatsink block to the ESC's metal back plate and then closed it up again with transparent heatshrink tube. Looks neater than the original.

Overall the result is very pleasant. Torque is way up, this ESC has a proper brake (which the original didn't have) and with the tiny brushless motor (a powerhouse despite weighing only a measly 58g) I get very nice long run times even with the old original nicad battery. The reduced weight up top helps too.