https://youtu.be/9bXLq_9CW4c This is the one I'm building. Most if not all of the material can be scrounged for free. 12v wiper motor (Got one from my buddy who's a mechanic), 12v laptop power supply ( Found an old computer power supply someone didn't need or you can use a small 12v battery and low amp charger), an old bed frame ( I always find these being thrown away I keep 1 or 2 around) , 3 position 6 pin switch (You can use 2 single throw toggles to reverse polarity also), 2 rubber casters ( I had these kicking around), extension nut and bolt (I bought these mine needed metric thread), The feet I'll make with 4 bolts and rubber or cork stoppers if I don't have something else that will work. The barrel is 2-5 gal. bucket and I'll bought a screw on lid that fits 3.5gal to 5 gal bucket from Home Depot for $8 (http://www.homedepot.com/p/Leaktite-...MMA6/203205720) All totaled I have about $12 invested in the project.
This is the overview https://www.youtube.com/watch?v=MchjmCIvzlY