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one engine, tank treads?? — Parallax Forums

one engine, tank treads??

roughwireroughwire Posts: 78
edited 2009-05-15 14:47 in Robotics
I've got a 3Hp Briggs and Stratton engine, and I wanted to make a mini tank of it, but obviously with one driveshaft, I can't control two sides. I was wondering if there was a way around this. possibly some kind of separate clutches or something?

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MIKE

Comments

  • AndreiAndrei Posts: 15
    edited 2009-05-05 07:27
    I have seen something on youtube, few months ago. a robot with only one engine. I dont' remember the name but it exists.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-05-05 08:41
    A couple variable speed pulleys might work.

    -Phil
  • kwinnkwinn Posts: 8,697
    edited 2009-05-05 12:28
    I recall reading about a transmission that had a small electric motor for steering. As I recall when the motor was not turning both outputs from the transmission were the same speed, and when the motor was turning it would speed up one output and slow the other. The direction the motor was turning determined which side was faster and which was slower.

    I think the article was in Popular Science or Popular Mechanics, but am not sure. For sure it was a long time ago.
  • kwinnkwinn Posts: 8,697
    edited 2009-05-05 12:30
    PS - With a differential and brakes on both sides you could apply the brake to one side to turn.
  • W9GFOW9GFO Posts: 4,010
    edited 2009-05-05 20:41
    You could use a transaxle from an old riding mower and brakes for differential steering. The transaxle because you might want to reverse direction. I don't see how you would be able to pivot though, unless you used two transaxles. You might end up spending more on stuff to make it work than if you just used two electric motors.

    There's also hydraulic like the Quad Rover, or Hybrid like it's predecessor.

    Rich H
  • icepuckicepuck Posts: 466
    edited 2009-05-06 00:14
    The Eaton model 6 or 7 hydrostatic transmission would be one way to go or just copy the quad rover. If you go with hydraulics like the quad rover, anything to do with hydraulics has to be perfectly clean. Don't forget the filters, one spec of anything floating in the oil will destroy pumps and motors.
    http://hydraulics.eaton.com/products/trans_main.htm
    -dan
  • P!-RoP!-Ro Posts: 1,189
    edited 2009-05-06 01:09
    One possibility is to have the engine create electricity, and have two motors control the wheels.

    If you want this project to be inexpensive, one possibility as well is to use a belt and pulley system, with treads turning when the belt is tightened with a small motor.

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    PG
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-05-06 01:44
    Pi Guy,

    That's the best suggestion I've seen so far! Hybrid automobiles and diesel-electric locomotives are both good examples of this principle.

    -Phil
  • kwinnkwinn Posts: 8,697
    edited 2009-05-06 03:41
    Connect a car alternator to the gasoline engine ( up to 80A at 12V ), use 12V motors to run the tracks and have power for the electronics to boot. What more could you ask for?
  • P!-RoP!-Ro Posts: 1,189
    edited 2009-05-08 01:34
    Phil Pilgrim (PhiPi) said...
    Pi Guy,

    That's the best suggestion I've seen so far! Hybrid automobiles and diesel-electric locomotives are both good examples of this principle.

    -Phil
    Hardly, you can thank Ken for that:
    http://www.parallax.com/Store/Robots/RollingRobots/OutdoorHybridRoboticPowerPlant/tabid/625/Default.aspx

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    PG
  • UghaUgha Posts: 543
    edited 2009-05-15 14:47
    You could always do a half-track design that uses the engine for forward/reverse and a second motor for steering.

    This would let you use a much weaker motor on front to direct the wheels and save the engine for serious power.

    Post Edited (Ugha) : 5/15/2009 2:54:58 PM GMT
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