I have a couple pieces of OPE sitting around not doing much and I have this project (read: backyard mad-scientist experiment) in mind that could use some brainstorming help. I'd like to build a go-kart that used a serial-hybrid powertrain: gasoline engine turning a generator that sends the electricity to motors at the wheels. This only needs to be big enough for a child and won't be seeing terain rougher than a sidewalk or yard. I'd like to get all the powertrain parts from the junkyard or surplus vendors and use one of the engines I have sitting around.
The engines I have sitting around are: 2-stroke McCulloch trimmer (?hp), 2-stroke Lawn-Boy (4hp), 4-stroke Craftsman (sticker says 6hp but I think that might be a little optimistic). The trimmer motor is in the best condition and will run in pretty much any orientation but obviously it's also the lowest power output. The Lawn-Boy motor is also in reasonably good shape but it will only run right-side up or up-side down AND I'd have to make some kind of muffler for it since that's integrated into the deck. The Craftsman is in the worst shape with lots of blowby, can only be run in a single orientation but is also probably the highest output and quietest.
My first idea is to get a one-wire alternator for the generator driven by the trimmer motor and use electric window motors at the wheels.
Possible problems:
1-Will the trimmer engine put out enough power
2-Can I throttle this at the gas engine or will I need to build a chopper circuit to do that much? Could a two-wire alternator's voltage be throttled externally or will it really only produce useful output in the 10-16v range?
3-Is a window motor able to take the side-loads that would come from having the wheels mounted directly to them or will I need to have a real axle? Is there another motor available that is both CHEAP and AVAILABLE that would be better suited?
The engines I have sitting around are: 2-stroke McCulloch trimmer (?hp), 2-stroke Lawn-Boy (4hp), 4-stroke Craftsman (sticker says 6hp but I think that might be a little optimistic). The trimmer motor is in the best condition and will run in pretty much any orientation but obviously it's also the lowest power output. The Lawn-Boy motor is also in reasonably good shape but it will only run right-side up or up-side down AND I'd have to make some kind of muffler for it since that's integrated into the deck. The Craftsman is in the worst shape with lots of blowby, can only be run in a single orientation but is also probably the highest output and quietest.
My first idea is to get a one-wire alternator for the generator driven by the trimmer motor and use electric window motors at the wheels.
Possible problems:
1-Will the trimmer engine put out enough power
2-Can I throttle this at the gas engine or will I need to build a chopper circuit to do that much? Could a two-wire alternator's voltage be throttled externally or will it really only produce useful output in the 10-16v range?
3-Is a window motor able to take the side-loads that would come from having the wheels mounted directly to them or will I need to have a real axle? Is there another motor available that is both CHEAP and AVAILABLE that would be better suited?