DualGrip-NXT Rover

MCP Dave Astolfo has published a new NXT robot of his: the DualGrip.
As the author states:

"The idea was to have a treaded robot that could navigate varying terrain, turn quickly and of course, climb.  Based on my experience with my other robots using the same tracks (eg UNV and DynaTrax), I found that they were not very good when it came to inclines.  I figured that the LEGO rubber wheels have great traction on most surfaces, so why not slap a set of them along with the treads."

The point with the DualGrip is that it switches from tread drive to wheel drive when it encounters an incline - pretty good idea, isn't it?



Have a look at the three web pages associated to the robot - there's a lot of information on the DualGrip to be found, including two more movies.

New(er) Style Tread Links

A friend of mine, John Brost, recently asked me if I had noticed that there were two types of the new tread links out there. Surprise surprise, it seems LEGO has modified the mold slightly. The new tread links will work fine with the old ones - there's no difference in the parts that connect link to link. However, some small new "bumps" on the new treads do change a few things for robot builders. First, they tend to make the side-to-side stability a little better (a good thing). Second, it means that using them "backwards" to form large wheels now works only with still larger diameters. Mixing them in an alternating fashion makes small "old style" (?) tread link wheels work... but you'd have to pay very careful attention to make sure multiple "new style" links aren't adjacent, or you might end up with flat places in your wheels. As to the why for this, it might have been to increase the side-to-side stability, or it might have been to allow better flow in the molds and less rejects due to bubbles (suggested by Bryan Bonahoom, who knows much more about these things).

Now, if they would just come out with a rubber "shoe" for these links...

Treads available for LDraw

Philo, MCP and relentless Wizard of LDraw parts, has published LDraw files for the treads contained in the NXT Education supplemental kit (other configurations of the treads can be found here and here).
Hence you can model your NXT robots that run on these treads now in LDraw.

Thanks, Philo!