Make gadgets for around the house? Build a deck or tree house? post it up!
My buddy CJ and I are building a go-kart / power wheels racer for the “Power tour” a nerdy racing series about building budget vehicles in the style of, or out of, powerwheels cars and racing them.
There are size contraints a budget limit is 500 dollars and we have a max amperage load we can run for the voltage we are running.
our entry is going along pretty well. Its mostly made of found materials, the frame steel is from a bedframe. The GO will be provided by the motor from a tread mill and 2 12 volt batteries we will be wiring in series.
Nearly everything else we are fabricating as best we can in the humid Florida summer.
This is the result of many months of tuesdays of planning and building. Since we are building around the human body and driving comfort (which we cant represent on graph paper) its come together in stages. Basically we do a thing, sit on it realize it feels wrong, or isn’t going to work and change it.
The trouble with steel, thin steel in particular is that the welds you make when hot shrink when they cool so everything kinda pulls together. If your welds aren’t even it twists up and gets wonky.
well… it rolls! still some work to do on the control system. you gotta surf the throttle and if you go too hard or light it resets. closed loop control is the next step
The rear tires are maybe too meaty. We are actually having trouble overcoming the inside wheels’ grip in slow corners. The tiny front wheel really dig in hard and the cart will turn on a dime.
My bud CJ got it up over 20 mph looping his neighborhood so its quite quick but not as quick off the line as Id like. Theoretically the top speed should be 40 based on measurements taken while the motor was full unloaded.
To solve the throttle issue we are installing a hall effect sensor that will read a magnet attached to the drive sprocket on the motor side. This will essentially give us a little blip every turn of the drive socket which is about 5 inches in distance traveled. The blip frequency will tell us exactly how fast the motor is spinning. Given that we know that there is a safe window of speeds to request around that motor speed we can limit our inputs to that window, updated in real-ish time.
So these things are basically setup in a mounted starting area and a thing flips up with a nail on it, which pokes a hole in the end of the CO2 canister. This particular canister isn’t the standard used for dragsters. Its from a Bicycle quick-fill flat kit. I just stuck it in there because!
On the bottom here, I hollowed out some of the body, to save weight. And then I soaked a piece of copy paper in elmer’s glue, to seal the cavity with some rigidity.
There’s like an competition standard for these things which we were made to adhere to. The wood has to be a certain width around the axels, body length, the C02 chamber has to have certain thickness, guide wire loops, etc!
