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Best place to buy the best cheap motors

  1. Apr 24, 2017 #1
    Basically, I am looking to buy some cheap motors.
    Basically, I am trying to build a small 1 person car that can drive on the sidewalk.
    Trying to find out the best and cheapest small motors. Preferably with a throttle.
    These motors would only need to move 250 lbs at 20 mph or 30 mph.

    I want gasoline or electric motors but basically any kind of motor I am open to alternatives. If electric then what battery do I use, I dont want to use a car battery but a strong battery I can plug into walls.

    If this belongs in engineering forums I am not sure, but please move it there if so.
     
  2. jcsd
  3. Apr 24, 2017 #2

    Evo

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    I don't know the laws where you live, but everywhere I've lived, it's illegal to drive anything on a sidewalk, here it's illegal to ride a bicycle on the sidewalk, it's for pedestrian use, it has to be designated a bicycle path.
     
  4. Apr 24, 2017 #3
    As a scientist, I am more concerned with the physics over the legality. In any case, it is legal for bicycles to be on the side walk where I live, but if need be, I can just ride it around in my parking lot until I speak with a legal expert.
     
  5. Apr 24, 2017 #4

    Evo

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    Yeah, I'd just hate for you to build a cool little car and then not be able to drive it anywhere. And I'm pretty angry about not being able to ride my bike on the sidewalk, no one walks on the sidewalks here and the roads are too dangerous for bikes, there is no space between the curb and the car lane, the car lane ends at the curb.

    Good luck on your project!
     
  6. Apr 24, 2017 #5
    I think you should move here because this is the land of free-roaming bicycles that may ride on sidewalks and roads. I wish you luck on your voyage if you decide to move here. I have also seen people riding ridiculous motorized contraptions on roads here, such as a motorbike with small wheels and a seat less than 1 foot off the ground.
     
  7. Apr 24, 2017 #6

    Evo

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    The cops here would never allow it. Very strict. :frown:
     
  8. Apr 24, 2017 #7
    I had an uncle who was an extremely good mechanic and when I was a kid he built a lawnmower motor powered go-cart for my cousins. It was amazing: he rigged up a transmission from pulleys and fan belts that toggled into place by lever. That transmission was really the secret: he, himself, an adult, could drive it around and do 30 MPH. It had 3 speeds. I don't remember the horsepower of the motor, but it wasn't very much at all: as I said, it was from a lawnmower.

    He made a track for it in his yard, which was pretty big. They didn't ride it on the sidewalk.
     
  9. Apr 25, 2017 #8
    If you want a small engine that could be used for something like that, I'd recommend a horizontal shaft engine from an application like a snowblower, roto-tiller, (large) air compressor, generator, or something similar. You can find those items on craigslist in various categories. Another option is to buy a horizontal-shaft engine brand new from harbor-freight

    Most of the single-cylinder air-cooled lawn more type engines will have a mechanical governor on them which limits their maximum engine speed to approximately 3600RPM. You can disconnect that governor linkage and actuate the throttle position directly by means of a throttle cable. The maximum engine speed will then be well above 3600RPM, but operating at high load above the intended speed range will decrease the lifespan of the engine.
     
  10. Apr 25, 2017 #9
    Hmm, thanks for the advice. I shall start shopping on craigslist one of these days.
    That is why you should move here.

    Lawnmowers have more HP than chainsaws, based on my google results.
     
  11. Apr 25, 2017 #10
    For cheap and new there is Harbor Freight - gas, they have some cheap electric motors - but then you need a motor drive.

    If looking to repurpose, Gas, yes there are lawnmower curbside all the time. For Electric you may get by with a treadmill motor, may not get you to 30 mph - though ( which relating to the discussion above - is too fast for a sidewalk - IMO). Used golf cart part may work as well.

    You may find the other issues like form factor, type of controller, etc have as much to do with what to use than just "best and cheapest small motors"
     
  12. Apr 25, 2017 #11
    An old lawnmower could probably be found at a Goodwill or Salvation Army. They are usually between 3 and 5 horsepower, more than enough to propel you. I've known people who have used lawnmower engines for everything from go karts to hovercraft.
     
  13. Apr 25, 2017 #12
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