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.

While Youn Ji so generously gave me her time in trying to make a pattern for the insecurity prosthesis prototype I put together last week, it became clear that using a pattern to cut and sew silicone together is not going to work–my prototype is just too irregularly shaped for pattern precision. What I need to do is to think about what it is I want to get done with this piece and what is feasible in terms of this timeframe (always remembering that there’s time later to complete things).

There are a couple of routes I can take. I could try to make some plaster casts and do molding and casting using silicone, but I am already neck deep in this unfamiliar technique for the anxiety prosthesis and would maybe like to lighten that cognitive load a little. Putting all of my eggs in this basket, as it were, becomes a little terrifying. Another thing I could do is to take the form that I’ve already made, get some more mesh and maybe sculpt over it, solidifying the form (maybe casting over it), and then using medical fabrics to upholster it in a sense, calling it a prototype sketch and mentioning where I want to go with it.

It’s especially worth remembering that I am presenting this stuff in my thesis class in three weeks, and during thesis week in five. Food for thought.

Well, after a number of false starts, I talked to
Daniel Liss, got his AT settings for an autonomous xbee broadcasting garbage data, and can use the Processing program Tom Igoe wrote here to monitor the strength of the signal. What’s left to do today is to modify Daniel’s arduino code to PWM the LEDs in the boxes I’ve been working on.

(more…)

I needed a good way to route the power into the boxes that would be clean and work well. I driled holes into the side of the three boxes that I’m going to have in the end and routed out space for a DC power jack. Now they can get power and look kind of like something you might buy at Ikea.

Now, All I need to do with these guys is make the xbee range detection work, and get some silicone to make tops for them, maybe two days’ work. Excellent!

Also, some pictures of the newly-reassembled casting:

I went to blick art after thesis class today and got some sculpting mesh and some plaster bandages. The plaster is for reattaching the shoulder pieces to the back cast. With the mesh, I sketched out a general shape for the insecurity prosthesis. I wrapped it in some fabric that I saw Rory leave on the junk shelf yesterday. After pinning the fabric around the mesh armature, I pinned the heating pad to the underside.

It goes around the neck and shoulders and hangs down onto the chest. It works pretty well, gets nicely warm (even if not very heavy) and hasn’t caught on fire yet, which is a kind of success. Drew Burrows, Kyveli Vezani, Robert Moon, and Rory Nugent were kind enough to model it for me.

I think that what I’m going to have to do is to make a pattern from this shape, and then cast and cut the pattern out of silicone, eventually sewing it together with the ubiquitous red thread. I need to think of something that could fill it that wouldn’t cause a fire or electrocution hazard. Aesthetically, I’d love for it to be really well sealed and to be filled with water, but that would be pretty dangerous with an AC heater involved. Maybe rice or lentils, but that seems to subvert the medical angle. small glass or plastic beads? that seems like it’s getting expensive. Stuff to think about, I guess.

I figured I’d put up some shots I took of the cast that I’m working with.