Self balancing one wheeled electric skateboard

Step 3 Overview

Here is the finished machine with the top deck and one side removed. Folded alloy panels run across width of machine and the two sides are made from 3mm laser cut steel. The sides were designed in "emachineshop" software downloadable from an engineering materials website of the same name. They could easily be hand sawn but the laser method allowed (most) of the holes to be cut neatly in the correct places.
From right to left: Box containing an Atmel ATmega32 microcontroller (small computer in a chip), plus an accelerometer, plus a solid state gyroscope. This takes voltage inputs from accel and gyro then decides how much power to send to motor to keep level if tipping over. A signal is sent to a motor controller in box on far left, which then sends the appropriate amount of power to the motor (to right of the central wheel). Motor is 420W golf cart motor and drives wheel by a chain. Wheel is widest available kart rear wheel that is sold.

Comments

[verticalfuzz]

I was wondering about the estimated cost of a project like this. I would very much like to make this board.

[XenonJohn]

It might be best for you to work this out for yourself, however here are some pointers: The microcontroller on a board with input/output pins etc is quite cheap. They can be bought from robot webstores, they feature heavily in past Make magazines and there are probably a few being used for other things in instructables. The accelerometer is not that expensive but fiddly to solder. My gyro was quite expensive. However since I started this Sparkfun have brought out some small boards with accelerometer/gyro combinations mounted on them. This would be lowest cost and easiest way to do it. You could always build, program and test your control system with a small cheap toy motor and controller leaving the rest until you have more money. Buy the big motor, big motor controller and batteries later. There are many Chinese 250-500watt motors on ebay for scooters. More specialist ones are in robot webstores for heavyweight robots. My motor controller was the OSMC (look it up with Google). All sprockets chains etc were for karts and obtained via ebay. Top speed: not known yet. Depends on sprocket combinations but probably up to 20mph on level surface (if you dare).