Another TechShop member (who was in the middle of a 3d print), asked me how I liked the vacuum-forming machine. I told him "Distressingly analog." I think he got what I meant.
For all that the high-tech fabrication methods are replete with numbers; for all that they come (often) out of computer models, go through digital positioning; and for all that the knob-setting is replete with numerics and other quantization, the final results still depend too much on the less quantifiable.
Even at the laser cutter; although the beam position may be as accurate as 10 micrometers, and the beam around .001 inches wide, the width of the kerf will depend on not just the laser settings but how good the focus is, how flat the table is that day, even the color of the plastic.
I've been lasering out holocron pieces with an aim to get a good snap fit. But the necessary precision for this is roughly the same as the variation in thickness between different sheets of material from the same manufacturer, and variances in how wide the laser kerf is. I can adjust the latter a little to take up errors in the former, but that still means trial and error. As digital as the process seems, it needs that analog touch, that craftperson's touch, to get the desired results.
This was my first start-to-finish use of the vacuum former as part of the build of a prop. This is the oxygen mask for the pulp "space" helmet. And as usual, half the techniques were chosen because I wanted to learn more about those techniques. And half the remaining decisions were forced by time and availability of materials (I'm trying not to spend much on this particular prop!)
I reinforced the first try with plaster bandages, and when they started to dry out and come apart, paper towels dipped in white glue. It was heavy and didn't look right and I abandoned it half way through the modeling process.
The selection of air-hardening clay at my favorite store was poor, so I tried Sculpey for this project. It will never replace FIMO in my heart.
Which was an adventure on its own. I used a toaster oven rescued off the street. Those things do not have precise temperature control, and my first cook was a little cold. My second cook burned the material, and because the additions expanded slightly, it cracked the surface. A little Bondo repaired that, but that made sanding an even more onerous task. I'll use clay next time!
Oh, yes -- and after taking this shot, I re-thought how the inlet should work, and built up a different shape on the finished sculpt.
But I was able to repair the buck with sandpaper and some quick spot putty, and it held up for the pull to the left without collapsing. So it was a good mistake; now I know more about the limits of the material.
Today I picked up webbing and d-rings. Not quite right; I'd like some nice hardware and leather straps, but the only place for those seems to be Tandy, and I'm eager to get this thing out the door. And keep the expenses down on it, too.
In the meanwhile I made a plaster mold from the bits of carved foam and apoxie sculpt I carefully pressed into the eye slits. The mold looks horrible and I'll be lucky to have one good pull from it. I'll be pouring clear acrylic into it tonight.
I have several different approached to the insignia on the painting table. The only other major bit for this prop, then, is to create substitutes for the vintage oxygen canisters (which are chemical oxygen generators that we almost certainly do not want to open up). I've been measuring soup and oatmeal cans but it looks like I'll have to fabricate these from scratch as well. There might even be a little vacuum forming for the distinctive top (or I might do as I did for the insignia; heat it up with hot air gun and press it over a form with my fingers).
I need this project to complete and clear the decks. My holocron just got a mention at Adafruit, there's interest at the RPF and the Jedi Master is getting closer to purchasing a half dozen or more for his students. And the "Tiki" raygun needs to start machining before the end of the month!