Track Designs

I received the Lynxmotion treads today. They look much better in reality than in the images on the web. I think the dimensions of the larger size treads look more right than the smaller ones. I also received a number of sprocket wheels and hubs used for connecting the sprockets to axes and it all look very promising.

I know you are supposed to make your design first and buy part later, but I have learned that this only works the second time you are building something. You really need to see and feel the parts to realize how they can be used. I am hoping for a design where the motors can be places inside the tracks, but I am not sure whether they will fit. It will take some thinking to get it right.

First, however, I will need to decide on which type of tracks the robot should have. There appear to be essentially five types around that can bee seen in the figure below.


Type A is used in many robots and is obviously the simplest one to build. For example, it is used by the military Swords robot by Foster-Miller, as well as the Trackster and the MMP-30.

Type B is used by the PackBot robot. The flipper allows the robot to climb stairs and negotiate rather complicated terrain. Although it would be tempting to build something like this, the mechanics of the flipper is probably a bit too complicated. Since my robot will be too small to climb stairs anyway, this extra complexity may not really be needed.

Type C and D are the kind you would find in most military tanks. Type C seems to have fallen out of fashion after World War I so we can safely assume that type D works better - probably since it allows for backward driving as well.

Type E probably does not have any advantages over A except that it looks much more interesting. It is also the track design for everyone's favorite movie robot Johnny Five, which is almost enough reason on its own to use this design. One possible role for the top wheel may be to stretch the treads. This is often the case for the top back wheel of design D.