Wednesday, December 29, 2010

CHOC Holiday Visit

Today R2 visited Children's Hospital Orange County, to spread some pre-New Year's Eve cheer to the patients.

R2 was bedecked in his New Year's Eve regalia, and used his new party horn to the delight of the young patients.

R2 was accompanied by Victor Jimenez as a Jedi Knight, and escorted from room to room by our contact at CHOC, Amber.

As usual, pictures with patients were limited, and on this visit the opportunity didn't arise to ask for or receive permission for pictures with patients, so this update will have to forgo pictures of the visits with patients. Suffice it to say we visited many kids, and one in particular really lit up when he saw R2 and a Jedi Knight come visit. We handed out stickers and action figures to the kids as we went.

On his way out, R2 spotted some tasty looking gingerbread houses. It's a good thing he prefers motor oil to human food.

Tuesday, December 28, 2010

Completed New Year Mystery Project

A few days ago I had mentioned that I was working on a little mystery project for R2. Because R2 is scheduled to visit the Children's Hospital again tomorrow, I decided that he would help ring in the new year a little early as only he can. This project is not for any particular New Year's Eve celebration he'll be attending, it's just planned for the hospital visit.

After testing how to use a can of compressed air with a couple of different party horns, I found the most effective method was to attach the horn directly to the can. I did this with a nail, as I showed earlier. How will I mount the can in the proper place inside the droid? Duct tape! It only needs to hold for a couple of hours for the hospital visit, and I'm far too lazy to come up with a more elaborate solution.

Well, you can't have R2 in a celebratory mood without a party hat, right? I picked up some poster board and gift wrapping paper, and prepared to go to work.

I want the hat to be 12" tall and have a 12" diameter at the base. Applying the Pythagorean theorem and some radian-based geometry yields an angle of about 160 degrees, and a radius of 13.4".

I debated over whether to tape the poster board into the cone shape, or glue it. In the end, I decided on tape, in case I need to undo the cone for some reason.

I'm happy with the test fit.

I cut the gift wrapping paper just a little bit larger, and also taped it in place on the poster board cone.

And a little blue and white ribbon to match R2's color scheme for the top of the hat. Later, I stapled some elastic to act as a "chin strap" to help keep the hat on.

Finally, I programmed a "Happy New Year" message on my Ben/Jason/Dave top front logic board. Time to try it out!

Hopefully this will work as planned for tomorrow's hospital visit.

Sunday, December 26, 2010

Drilled Frame for Skirt

Today I spent some time drilling the frame for the screws that will attach the skirt underneath it.

On droid #1, I used a total of six #6 wood screws, and so far this has worked out just fine. I have found that I use the skirt to slightly lift the front of the droid (well, the front foot) off the ground fairly often when I have to clear the occasional obstacle, so I decided I wanted to make the skirt attachment to the frame even more sturdy. I'm going with twice as many screws, and I'm using #8 wood screws this time.

First I used a 3/32" bit for the pilot holes.

Well, I was using a 3/32" bit, until I managed to break it with one hole remaining to be drilled. And then I broke it again pulling it out. I used a 7/64" bit for the last hole.

I then countersunk each hole.

I tested the fit of the #8 screw in the various holes, and all seems well.

I could have finished the job and attached the skirt, but that would have meant measurable progress, and we can't have that.

Thursday, December 23, 2010

Finished Work on Foot Hoses

Today I finished up the last of the foot shell hoses. It was pretty much a replay from yesterday: Cut hose to size, pull out original inner tube, replace with slightly smaller tube, install knurled fittings.

I picked up some some #6 knotting anchors to help push the inner tube out against the braided hose.

The tip at the end is sealed, so I temporarily screwed the #6 screw in from the opposite side to open it up first.

I then reoriented the screw into the other side of the anchor and started screwing it in place in the anchor, with the whole thing inside the vinyl tube. I used a pair of needle nose pliers to keep the anchor from rotating as I turned the screw into the anchor.

As the screw gets turned further and further, the anchor starts to bunch up, causing the vinyl tube to bulge. This is what I want.

I jammed this back into the hose, and gave a few more turns with the screwdriver, and the anchor did its job. Everything is reasonably tight. If needed, a layer of masking tape around the vinyl tube could make things tighter, but right now I don't think that's necessary.

I wrapped up by starting on a little mystery project. I drilled through the nozzle of one of my cans of compressed air, just below the hole where the air comes out. I also drilled through another object, and used a nail to secure the object to the nozzle.

What could it be? You guys are a clever bunch, I'll bet you've already figured it out.

Wednesday, December 22, 2010

Started Working on Foot Hoses

Today I worked on the hoses that run between the battery boxes and foot shells.

I'm using 3/8"-diameter brass braided hose that I picked up at Lowe's. Each hose is 20" long. The blueprints call for the hose segment to be between 11.5" and 12.5", so it needs to be cut down.

The first step is to wrap the hose with tape, to help prevent the ends from fraying when they are cut. The brass fibers are sharp too.

Next, I used ye olde tin snips to cut the end off. I think the last time I used these was when I was working on the hoses for droid #1.

Although the hose is spec'd to be between 11.5" and 12.5", I measured off 14.5" and wrapped masking tape around the other side to be cut. The extra length accounts for the the fact that the knurled cable fittings will cover a couple of inches of the hose.

Then, I did something different from droid #1. I pulled the inner tubing out of the braided hose. I did this because it is very difficult to jam the hose into the knurled cable fittings. I replaced the tubing with a thinner one, as I'll show momentarily. I had actually tried jamming everything into one of the fittings at first, and I succeeded, but I decided this is not the way I want to go this time.

I purchased some vinyl tubing from Home Depot. The dimensions are 3/8" outer diameter x 1/4" inner diameter x 10'. I'll use this inside the braided hose instead. It's just a little thinner than the braided hose, but enough so that the knurled cable fittings can fit over the hose. The tubing is required to give the hose inner support. I plan to do as Mike Senna did, and use an expander to force the tube up against the braided hose to prevent the tubing and knurled cable fittings from sliding about.

I measured and cut the tubing to length, and threaded it into the braided hose.

Finally, I slid the knurled cable fittings on. Unlike the fitting on droid #1, these did not put up much of a fight.

Three of the four hoses are done. I want to redo the first one. I made enough of a mess of it when I was jamming it into the knurled cable fittings with the original tubing inside, that I'll pick up a replacement and then finish it up.

Tuesday, December 21, 2010

Unmasked Dome Ring

After a ridiculously long break from building, I got ridiculously little done. (In slight fairness to myself, I was sick a few of those days.) Tonight, it was (beyond) time to unmask the dome ring that I painted a week and a half ago.

Off comes the masking tape on the top half.

And off comes the masking tape on the bottom half.

Unfortunately, a small area of paint chipped away during the unmasking process, even though I went slowly and carefully. I think this was due to letting the masking tape ride a little too high when I originally applied it.

The good news is that Roy Powers discovered that the Uni-ball Vision Elite dark blue pen is a very good match for the blue formula I use.

A minute or two lightly tracing over the bare areas, and it's virtually undetectable.

The dome ring work is done, and it's ready to be attached to the dome.

I had hoped to get a lot of painting done this week, but it's been raining here in sunny Southern California for almost an entire week, with more rain on its way tomorrow, so that didn't happen. Maybe next week.

Wednesday, December 15, 2010

Installed Half Moons on Foot Shell Doors

Tonight I spent some time installing the resin half moon pieces onto the foot shell doors.

For each half moon, I started by taping the part in place on the door.

Next, I measured and marked where to drill the holes on the back side of the door. I'm using 1/2" #4-40 screws, so I need to drill at least 1/2" deep.

I used another half moon piece underneath the work to keep it level, and perpendicular to the drill bit.

Then I drilled the holes, using a #43 drill bit.

Next, I screwed in the screws. The resin and plastic are self-tapped by the screws, so there's no need for a tap bit. I clamped the half moon piece tight to the door, to ensure that the threads that were being formed in the holes would meet up properly between the plastic door and the resin half moons.

Close enough.

I repeated the process for the other center foot shell door, and the outer doors.

That's one more thing out of the way, many more to go.