BorisArchive

From Simreal

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Older, Archived Photos of Boris

First Prototype

... ugly, inefficient, but a start

When I started out on this project, I had nothing for metal working tools. The most expensive tool I purchased was my oxy/acetalene welder (and now I just love to weld!). The most "precise" was this cutoff saw... and I hope to prove that it is possible to build a high-tech robot with simple low-tech tools.

Don't laugh -- I know this first leg is ugly. But it was a start! The bored kid holding the leg is Harry.

The joint in the leg was like a piano hinge... and a pain to make.

I was also going to use McKibben muscles... but decided that standard pneumatic cylinders would be easier for this application.

Second Prototype

... getting better

The mechanism of the first leg was far too complex, and rickety. I hadn't worked out the "triangles" right. In this next prototype, I have moved to a form factor that is very close to final.

I also started using a new leg joint -- a simple flange and peg arrangement. Much easier to make, align, and it provides good strength and smooth action. To ensure the joints are on a line when I weld them into the framework, I put a rod through the holes before welding. Of course, the scale on the metal builds up and I have a hard time getting the rod out again, but the joints are nicely in line.

This joint style also allows for a simple attachment for a potentiometer, to measure the leg's angle.

Final Prototype

... best!

The greatest change from Prototype 2 to 3 is the placement of the cylinder for the shin. In the old prototype I put it in the knee joint itself. In between these tests, I tried it in several places above the thigh.... but I finally moved it to the more vulnerable but also far more practical location it has now, below the thigh.

Here are some more pictures of the leg, in simulated action. I don't have many photos at this stage of development -- but I promise ample pictures of the final robot as it goes together!