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Early Arm Prototyping

Overall results look good so far. We did a little experiment today – I made a rubber mold of one of the arms, then made a hydrocal copy of the original 3d printed part. We didn’t have quite enough hydrocal on hand, so I filled it with some expanding foam to give it a bit more structure.

Then we headed down to the local university, where we had previously discovered a vacuum forming machine buried underneath piles of other crap in one of their workshops.

It took some fiddling, some repairs, and some duct tape, but we brought the thing back to life and got it working. We banged out a quick test pull on some tools that were laying around and it looked like it would work!

This table’s definitely not big enough to accommodate the torso, but it’s certainly more than sufficient to give the arm a try, so we loaded up some more plastic and threw the hydrocal buck onto the table.

Not bad at all, once we peeled all the film off! Only one problem…

It’s a bit too small for my arm. Damn.

We’re going to go back to the 3d printed molds and build them up a bit longer with some monster clay and apoxie sculpt, then make rubber molds for each and do hydrocal copies. From there, we should be able to pretty effectively bang out pulls in the 1/16″ PETG sheets.

It’s an arduous process, but at least the end results are getting somewhere. I could probably do this with a heat gun and tons of patience trying to shape it over the hydrocal, but the table makes it a lot easier.

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