Just two wheels and a trailer

[rjohnson]

Arguably, discussion on wheels has been the most common topic this year. After reading many posts on this topic, I have not seen anyone talk about what I am about to propose.

I am thinking that you could use just two wheels on the robot with an axis parallel to the axis of the trailer and somewhat centered front to back. From what I understand the tongue is pretty rigid and would allow to trailer to act as the other balancing wheels. This configuration would allow for greater turning capabilities and virtually all the weight of the robot would be over the wheels (assuming if was placed close to the center of gravity of the robot) for maximum traction. The official drawings say that the tongue itself is aluminum and the tongue accessories are made of steel. I don't think this would put too much stress on the tongue as most of the weight would be centered on the robot wheels.

Please anyone share their thoughts concerning the viability of the design or other advantages/disadvantages that I have not considered.

[m^3]

You might want free spinning wheels on the front that would support the robot when no trailer is present, but rise a few mm off the ground with a trailer. Otherwise, I don't see a problem with it. If you do try it, could you post a vid?

[Hanna2325]

its interesting, especially if you do it in a way that gives you a lot of control. Ya, and a video would be great!

[Dick Linn]

http://www.chiefdelphi.com/forums/sh...t=71238&page=4

See the picture attached to post # 60. I was essentially asking the same thing, but I thought the trailer tongue was more rigidly coupled at the time. So the "sulky" is the trailer. Go for it! Simple is better.

(Yes, you would need a caster or idler wheel of some sort in the back when nothing is hooked up, but that's no biggie...)

[Chris Fultz]

although the tongue is rigid on the trailer, there is a lot of movement between the hitch connector at the trailer hitch and the hitch itself.

try some experiments, but i think the looseness (in the verticle axis) is enough that the trailer tongue and back of the robot would sit on the field surface.

[Ed Sparks]

We went down this road for a while but decided the hitch was just too weak.

[joeweber]

We did test this method, we built two trailers and found that both allow too much movement, also the rules state that the hitch is to be 2 13/16 inch off the ground and with the robot tipping forward and back that distance change would violate that rule.