Hi Robotdude,

I have the Thumper 4WD and I am using the same setup as you with the 2 H-bridges from the EZ-Robot store. It works fine for me, but I don't have anything heavy loaded on mine. Just some sensors. I usually run the H-bridges at 50% of power to get a reasonable speed for indoor use. Did you make sure that your batteries both have a common ground?

Also, can you post a diagram of the other wires you are using for the digital connections from the EZ-B?

Finally, what "indoor wheels" did you buy? I am trying to find some for mine.

With the big outdoor wheels I found that turning on a carpet was very difficult. In order to execute a turn I had to use a custom Movement Panel and set the speed on one side equal to about 20% of the speed on the other. For example, to turn right, I set the right-side wheels to 10% power and the left-side wheels to 50% power. That seems to work best.

Thanks, Mike

Hi Mike, My robot weight around 9kg and everything is connected to the same 12v battery so there is a common ground. I wired the digital ports similar to https://synthiam.com/Community/Questions/2745 So I combine the wires together to save ports on the EZB I used a very simple kid's bicycle training wheels with some small modification to make it fit into the motors. Are you sure that the 2.5 amp h bridge are enough for the Thumper 4wd? Why if I connect the battery directly I will get more torque? That shouldn't happen if the h bridge is strong enough no?

I think the main difference between my Thumper and yours is the 9kg of load on yours. I can assure you that I only need 50% power with the h-bridges to go pretty fast around my house. But I have almost zero load. So I haven't tried it with a large load .

What wheels did you buy for inside use?