need to no how to build and what i needgreenspun.com : LUSENET : Junkyard Wars : One Thread
hi iam only 14 years old. I make about 30 a month. I want a go kart because every body else got one and i dont. I need to no how to build one and i need to no what i need to build one. I dont need a fast fast one i need one that can hit28 mph
-- JayRonely (firstname.lastname@example.org), July 28, 2002
First off, you have to ask yourself where and how you plan to ride the thing should you get or build one. Basically, "on or off road?". If it is on-road, a couple of options open up that would be difficult for off-road. Basically, off-road pretty much demands at minimum a steel or aluminium frame, welded (preferable) or bolted together. Steel isn't cheap (even if you buy used steel, which is cheaper, it will still take you a while to get all the parts together). If you plan to only ride this on-road (which may or may not be legal in your area - keep that in mind), then you have some interesting options. You could use an engine or an electric (motor) drive. You could use ABS or PVC pipe for the frame (which is real cheap and easy to put together). Belt drives using swamp cooler parts (pulleys, shafts, bearings, and belts) are cheap as well (though not efficient - but who cares about that for a fun project). You could also use wood for the frame (but it will be heavier than PVC/ABS). For the seat, walmart sells cheapo plastic boat seats, or an old plastic school chair seat would work too. Also, go to walmart and ask about go-cart kits they sell - they will typically have one on display all put together - draw out the mechanisms to see how they go togther (or take pictures if you can get the manager's permission - explain what you want to do). The motor/engine will be the most expensive piece in the project - go to yard sales and look for chainsaws, etc. If you want a chain drive, look into used bicyles, like an old ten-speed (don't spend more than $10.00 for a used bike). Use the chain and sprockets then. Also, there are a few online go-cart projects, and many go-cart related pages that show pictures and such. Sketch out a lot of ideas, and bring them together, then plan the parts, etc - get a list, and start buying and building. To calc speed, you need to calc the circumference of the tires you are using, so one rotation=so many inches. Then divide that into a mile to get how many rotations you need to make to move a mile. Call this "rotations per mile". Multiply that by your top speed you want (say, 30 MPH) to get how many rotations you need to make in an hour, then divide by 60 to get the RPM. Once you know the back wheel RPM, then you must determine the size of the pulleys you are using, the ratio (in size) between the pulleys - say one is a 2 inch pulley, and the other an 8 inch pulley - that is a 1:4 ratio - so 4 rotations of the smaller pulley equals one rotation of the big pulley. Multiply that larger number by the RPM - and this is the RPM the engine or motor needs to be able to put out (be aware that these numbers do not take into account the weight of the vehicle and rider, rolling resistance, inefficiencies in the drive system, etc). Finally - whatever you build and ride - WEAR FULL BODY PROTECTION. I can guarantee you that if you get into a crash without a helmet, etc - you WILL GET HURT. This goes double for what is essentially an experimental vehicle. BE CAREFUL, and good luck in your quest.
-- Andrew L. Ayers (email@example.com), July 31, 2002.