Sometimes I build robots that attempt to solve real world challenges. Other times, robots are built based on random ideas. This robot is a case of solving a LEGO challenge – specifically, with their Technic tracks/treads #575518. At no fault of theirs, these plastic tracks are slippery on many surfaces. Great for carpets, flat areas, dirt (if you dare) – and great for turning as well. However, when you try to climb with them, they are as slick as ice.
If you Google them, you will find some great ideas on making these treads more ‘sticky’. Some have used 1/2 Technic pins (which fit nicely into the supplied holes), others have used elastics wrapped around them – all great ideas that work fine. I attacked the challenge from a different angle. The result is DG – or Dual Grip (yes, the name is somewhat plain). DG went through numerous revisions as I worked out kinks related to weight, stability, traction, sensors, flex etc. At the bottom I have included some pictures on previous versions of DG – some changes significant, others subtle.
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. However, this posed another challenge. I did not want both wheel systems in contact with the ground at all times as this would make turning tougher and be redundant.