Wiring up the drives

Well, I heard from the frame guy that he mailed out the center ankle hardware Friday, so it should be showing up tomorrow or Tuesday. In the meantime, I'm prepping the center ankle itself and also wired up the drive controller.

After talking to a few people, I decided to go with a switch instead of a diode arrangement, chiefly because I intend to roll the R2 around sometimes with no battery inside it. So I mounted a switch just below the main power one to control power flowback from the motors to the controller:

Just so happens I had a DPST (double pole, single throw) switch left over from my proton pack build, so I just used that. It has both motors going through it, so I can toggle them both at once.

Anyway, the driver itself looks like this now:

On the left, the top 2 wires are going to the left foot, the middle two to the battery, and the bottom two to the right foot. I'm using landscape lighting wire as it's extremely flexible for 12-gauge.

On the right, the top two wires are going back to the signal pins on the arduino, where they control the actual movement. The bottom one is a ground going back to the arduino's ground pin.

(You can also see that the DIP switches have been toggled over to the correct configuration, with 1 & 2 off, and everything else on).

So that has come together very nicely. I'm hoping I can get it together pretty quickly and have the robot scooting around before too long. At least I should have it on its own 3 feet by the end of the week, if all goes well. In any case, this pretty much makes the wiring-up portion of the build complete. So that's pretty cool.

Getting ready to wire up

So now that the legs are on, it's time to thin about the foot drives. I've been working to get those fastened together, and finally got that done Saturday morning. Pictured here is a foot drive with the rear caster mounted and the ankle mount clamped on:

Now I've got to wire up the actual drives. I grabbed some sheet aluminum the other day and cut it to 6x7 inches so that it would mount inside of the leg braces on the frame. Since the motor driver is too big to fit on my current motherboard I'm breaking it off by itself. And since it's got a big heat sink on the bottom of it I went with a conductive base attached directly to the aluminum frame. Here is the driver--a Sabertooth 2x32 (2 motors & 32A each) mounted to the plate:

And here's the plate mounted inside the leg brace:

Pretty exciting. Hopefully the center ankle hardware will show up very soon, and I can get that done. In the meantime, I had a little side project over at Hammerspace this weekend, where one of our members is doing a two-part class on building lightsabers. He brought in a whole bunch of plumbing parts and whatnot, and we put them together however we liked. I took mine home for a little painting and touchup work, and this is the result:

Next class, hes' going to show us how to add sound effects, and make it compatible with the popular "blades" available out there. Very cool. I'm thinking I'm going to have to make some of these for gifts for my geeky friends.

Incidentally: this weekend marks not only Star Wars Celebration VII (wish I was there!), but also month 4 of this build. I now am 1/3 of the way through my projected build tome to get R2 up and running. I do believe I'm more than a third of the way through the build too, so feeling pretty good about that. Will I make it? Hope so. But we shall have to see.

3 down, 9 to go

So, a quick update: Planet ComiCon went rather well, though I do feel that I have a hell of a long way to go compared to everyone else's stuff. It was so much fun being there, answering questions, explaining how everything worked.

Anyway, looks like the next one is going to be the Maker Faire in June or July, I forget which. I've been thinking about then, and trying to decide what I want to have ready by then. Now, there's no sign of a skin run on the horizon, but I do have the legs more or less, and so I have decided to see if I can have R2 up and rolling around by then. Toward that end, I picked up a Sabertooth 2x32 driver for the motors, slipped in to the latest DDR2 foot driver run after there was a cancellation, and have begun soliciting info from other builders on how to put it all together.

I think probably the Sabertooth will not be going on the motherboard, if only because of the sheer size. Also, there is a heatsink on it, so I will probably mount it to the frame, let the heat dissipate. Still on the fence on 12v vs 24v. When the drives and things arrive, I'll have about 67 pounds of robot tooling around, so 12 should in theory do it, but I suppose in any case we'll see. The system I'm getting is easily adaptable either way.

In the meantime, I'm working on the legs. Got the horseshoes sanded down the other day and have begun to paint. I've got some nice white gloss which should do the trick. Then this weekend I'll see about sanding and painting the legs, possibly even starting to work on attaching the bits together. Come to think of it, need to print up some more ankle cylinders. Get a full set. Hopefully, the drives and things will ship out next week (I got some mounting hardware and a center foot mount as well so they can roll around until I get a foot shell) and I should be rolling along in the not too distant future.