Today's song is: Get Your Motor Running .. Get Out on the highway .. Looking for Adventure!
I continue to work on developing a test mule for my Lego motor driven cars. In the beginning Thavorn built expensive Lego cars and I attempted to motorize them. Making them move with one motor and controlling them with expensive gadgets imported from Hungary worked but I have this need for speed and control that was not satisfied.
Lego cars are really designed to look nice and sit on a shelf. The structures, particulary the gear differentail and drive train are made of plastic and have problems with heat due to friction and structural regidity. I resorted to strong elastics to hold everything together.
I also have 5 cars and I wanted to explore developing the electronics myself rather than pay upwards of $200 to firms in Hungary to control them. I had developed my first mule, controlled by Adafruit circuit playground and crickit drive board. I used a 10 volt NIMH battery pack to drive the motors which are rated at 9 volts but can take up to 11 volts without a problem.
It looks like this:
It is based on a Lego Corvette set that sells for $69. The electronics cost me about $70 which is much better than $200. It is also fast, but too powerful for such a small vehicle. I drive it with 4 gears and start it off at half speed to overcome the inertia before accelerating. If I apply full power from a stop it tends to pull itself apart. There is also a need to tidy up the wires and shrink the electronics down.
I decided to build another test mule with direct drive on the rear weels and switch from a rack and pinion steering system to a worm drive. I am using the original electronic boards but new ones arrive soon that will cut the price and size in half while maintaing the functionality. Both vehicles are controlled via bluetooth on my mobile phone. I wrote the python code that motivates the car.
My new test mule now looks like this. It is twice the size of the original and at least twice as fast!
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