Here is the PCB, fresh from Advanced Circuits. I threw it together and mocked it up with the battery from sparkfun for size. It looks like it’ll be fine. For scale, I measured it against my thumb. It’s a little thicker than I’d like, as I’m thinking about casting a resin box for it (probably not in time for the thesis presentation, more likely for the show), and the size may make it kind of unwieldy for a pocket. Otherwise I’m pretty happy with it.

The last couple days I’ve been doing some writing of the thesis paper. Tomorrow, I debug the xbee circuits with the new PCB controlling them, and hopefully plan out how I am going to build the insecurity prosthesis that has me kind of stymied at the moment. Triage time!

Also, this is a really nice review of the new Iron Man movie, talking about a lot of the same stuff that I’m working through as I write. Zeitgeist?

Today felt pretty good. I cast a new, thin layer of silicone for the top of the alienation boxes and sewed it on. Then I put together a bunch of the pulley wheels and attached them to the back of the anxiety prosthesis.

I took a break from the anxiety prosthesis to try stitching up the boxtops for the alienation prosthesis today. It’s pretty tough. I have a decent stitch going, but the thickness of the silicone makes it hard to do around all of the sides. Spending like 6 hours for one side of one box in the end is not very encouraging. I’m thinking of making new, thinner casts for the boxtops.

Today I finished sharpening the tool to cut out the shapes for the anxiety prosthesis. I got a whetstone, and went to town. I have a newfound respect for the skills necessary to do that kind of thing–keeping the blade straight enough to sharpen over the course of maybe a hundred strokes while trying to ensure that the blade isnt curving or getting any part of the edge off of the surface is tough.

In any case, I punched out the hackles and trimmed them off with an xacto knife. Now I’m in the middle of assembling the hardware to eventually control them. As usual, here are some pictures:

Today I demolded the skin from the second round of painting on silicone to the plaster cast. Here are some photos of the first result and some in progress shots of the second.

I also got some aluminum and made a tool for cutting out the hackles from the second skin, and marked approximately the layout of where they will go on the silicone.

Over the last two days, I’ve been working on making the silicone layer that will form the outer layers of the anxiety prosthesis. Operating on the excellent advice of Evrim Sahin, I brushed layers of silicone onto the plaster cast of the mannequin’s torso that I made earlier. It was kind of slow, messy, harrowing going. I wasn’t sure if the result would be very worthwhile, as every layer that I added on made weird looking ridges and drips in the silicone. Ultimately, after about 4 or so layers, I peeled it off of the mannequin and was astonished at the pretty decent quality of the casting. The part of it that was against the plaster ended up with a really nice, fleshlike texture, if a little bit problematic in places.

What I am going to do now is take the plaster cast, make another layer of plaster bandages as smooth as I can in order to make a somewhat larger and somewhat more consistent outer layer of silicone. I need two layers of silicone because one will be the base and another will be the layer that the hackles will be cut from. At this point, I’m really optimistic about how this piece will turn out.

This week’s theme is “oh man I really need to get on with building a mold and getting some casting done for the anxiety prosthesis, allegedly the centerpiece of my thesis work.” in the spirit of the theme, I got in today and build a jig that I will be doing the mold pour into. It’s ineterior dimensions are 2 feet square by one foot tall (approximately), meaning that I’ll need around four cubic feet of plaster to fill it. This mold is going to be pretty complicated. At least, it’ll be in three layers, in order to let me release silicone from both the front and the back of the shoulders, with probably around four pieces in the middle layer to let me release the top of the shoulders cleanly.

I’ve never made a large scale, remotely complicated mold before, so I’m pretty intimidated, but also fairly excited. I’ll do some research into the material to use and talk with Peter Mendelson, who teaches the Materials and Building Strategies course at ITP before I begin to pour. With that in mind, I think that the next step is for me to get my hands on some material to build the positive of what I want to cast in silicone on the cast of the mannequin’s back.

Well, things went pretty alright today–it looks like the light is being PWM’d by the xbee based on the distance and I have code that outputs the values (and what I modify the values into the PWM output) onto the screen. The next step is to find the right math that will make the xbee’s really inconsistent distance sensing work all right for the scale I want this device to operate in. This is going to be really rough, and I knew it from the start. the xbees don’t exactly operate on a precision ranging system, and it’s going to be choppy at best

Tom G mentioned that I should think about using #222 bulbs (the kind you may find in a flashlight) for the lighting source in the boxes. I like that idea a lot, and will probably install some TIP 120 transistors into the electronics package to control the relatively high-amperage devices. As it stands, the boxes will all have their own AC adapters, so current draw won’t be a problem.

today was fairly frustrating, but I’m pretty sure that I’ll get some good stuff from it in terms of knowing how to approach the problems I faced today next time. I took one of the boxes (the odd one out in case anything went irrevocably poorly) and drilled holes so that I could test stringing the silicone to the top of it. I ran into some trouble with the thread I was using.

I think that regular cotton thread is a problem in this case, bing too weak for the fairly heavy and resilient silicone. What I’m going to do early tomorrow is go to craft stores in the area and see if I can find a heavier nylon thread. I went through two spools of red cotton thread today and nothing worked very securely. On the brighter side, the McMaster order I made yesterday came in, so at least I can feel like I’m getting something done.

Also, the oiled woods and the red thread look great. This will be very nice, once I get past this hurdle.

Today I finally bit the bullet and bought a full gallon kit of the Dragon Skin silicone. For two hundred dollars, it’s nice that it includes around a gallon each of parts A and B, letting me make close to two gallons of silicone mixed.