Structure

A slightly different B9 Robot

Start at the bottom and work your way up.

The people who built the TV Robot did not have to worry about structure. They had a man inside to move and hold things up. The Slightly Different Robot will have to get by with man made parts instead of the man.

Starting at the bottom is the tread section. It is basically an aluminum box that can move. Bolted on top of the tread section are 4 lengths of 3" PVC pipe. Keep in mind that the "3 inches" is the inside diameter of the pipe.

Each pipe has a toilet flange at each end but only the lower flange is solvent welded to the pipe, the upper is a friction fit to allow assembly of the legs. Its just plumbing work, simple. Together the pipes and flanges are 23 3/8" long from flange to flange. They are bolted to the tread section and waist plate so that they are 8" (center to center) front to back and 9 3/4" (also center to center) from side to side. These dimensions are centered on the center of the tread section.

None of these dimensions are actually "official" but they do come close to what I have seen on other Robots. Feel free to change them as you desire.

And on top of the pipe sections is the waist plate made of 1/2" thick material. Having this simple internal pipe structure allows great design freedom of the leg/knee section.

On top of the waist plate will be the torso. Normally people have a central structure mounted on the waist plate that extends up through the torso, this structure does not rotate with the torso. To be slightly different I will not have a central structure. Electronics in the torso will be attached to and rotate along with it. The rotation motor is actually located just under the waist plate. A small battery will supply power to the electronics.

This all gives a number of advantages: lower CG due to lower mounted torso rotation motor, torso with continious rotation and no electrical connections between the leg section and torso. A simple mechanical connection of the torso with the waist plate will also make disassembly for transportation simple.

An advanced feature may be to replace the pipes with linear actuators. This would allow the Robot to pivot at the knees. Fantastic for up or down hills! CG would no longer be a problem. Maybe for the future, not right now.

So as far as the structure is concerned thats it. Everything attaches to this structure.