Wednesday, March 7, 2012

Thinking about MicroTrac



As an American, I am required to want a big tractor. I do in fact want a big tractor. What do I need though? Can I get by with less? Enter MicroTrac (Top Right) a small version of LifeTrac (Bottom Right).

MicroTrac is in the early phases of the development process. It's also a better size for my near future needs. So I've been thinking about making a MicroTrac when my PowerCube is complete. I've been thinking a bit about high level design for such a tractor. My thoughts are below.

Things it should be able to do:

  • Take interchangeable Attachments:
    • Snowblower, Lawnmower, Snowplow, String Trimmer, Mini Forklift, Tiller, others?
  • Powered steering.
  • Optional ride behind or ride in front (depending on whether attachment is pulled or pushed).
  • Low center of gravity. Reasonable stability & Balance.
To achieve this, I'm thinking of something like the diagram below.
Simple Concept for MicroTrac
It's primitive, but reasonably to scale. The cube in the middle is a Power Cube. It would rest securely in a frame. That fram would have two LifeTrac quick connect wheels attached near the midpoint. This keeps the center of mass low (but should still allow for maneuverability).

On the top are hydraulic valve controls which would control the wheels and the attachment. They would be movable so they could be at the front of the cube or the back. This allows the driver to push the attachment (snow plow) or pull the attachment (tiller).

The protrusion between the wheels is the attachment point. The would need to allow either a rigid or swiveling connection to a tool. To allow for loader type attachments (fork lift, bucket) there needs to be a more complex mounting mechanism available-- perhaps uprights at the back of the power cube that arms could attach to.

Finally, the drive could walk behind the tractor, attach a platform to stand on, or attach a seat of some sort.

My current reservations about this design:

  • Geometry - Will everything fit? It should be possible but might be tight.
  • Balance - There isn't a lot of weight in the back to keep MiniTrac from tipping forward. This is a big problem with lifting devices like a bucket, soil pulverizer, and forklift. Would a wheelie bar in the front help with those? Perhaps a caster in the back to keep from tipping backwards?
  • Maneuverability - How agile will it be? What sort of grade could it climb?
  • Ease of Control - The PowerCube is pretty powerful, how jerky will starting and stopping be? This can probably be mediated through clever hydraulics.
  • Ease of implement attachment - The attachment mechanism needs to be strong and easy to work. Perhaps us the same align + cam mechanism that the wheel modules use?
I'd love to hear feedback in the comments below. How can this design be improved? Any suggestions on attachment mechanisms? etc. etc. etc.