Mounting the Casters

Next I had to find a way to mount the casters at the right height, that would allow free rotation and a little bit of spring suspension. I settled on the all-purpose coat hanger for the job, along with some 5/16" O.D. aluminum tubing for the axle.

The coat hangers are just U-shaped, anchored at the corners by screws with large washers. Since they are cantilevered, they have a spring to them. At the caster end, the wire goes through holes in the 5/16 tubing to keep the casters in place side to side. All in all, the design seems to work very well. Here's a side view of the ground clearance:

Next is to see if the motors can fit in place, along with the casters and mounting screws. Here's a shot of all of it together for the first time:

It's starting to look like a robot!

As I was mounting the motors, I was trying to figure out a clever way to align the wheels precisely in line with each other, but I never found a good method. I ended up just eye-balling it, along with the help of a centerline across the diameter of the base as a guide. Here's a bird's-eye view: Does it look like my first sketch?

Now I started adding the next layer in the "wedding cake," using the plastic stand-offs. Some big holes in the next layer allow the wires to fit through, with their connectors, for easy removal if necessary. This layer will hold the motor controllers.

Here's a shot with the motor controllers in place, as I was planning the wiring and where to put more wiring holes:

I figured I wanted the battery as low as possible, but there wasn't really space in these lower layers, so I thought I would hang the battery from the ceiling of the next level, hanging directly over the motor controllers. Along with the battery I need to add a charger connector, charging resistor/LED, and power switch. Here's a shot of this wiring assembly in progress:

The battery is held onto the disc with that wonderful stuff, double-sided sticky-tape. What would we do without it? It also holds the switch and power jack in place. For the power jack, I made a simple L-bracket with a hole in it to hold the panel-mount jack. Now we need to connect this section with the lower level:

And now, before it's too late, I took off the white plastic protective layer from the discs. It make a big difference in the appearance:

Here's a side view of the bot in it's current state:

And one more shot, with the battery layer added:

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