After only six actual work days, a few afternoons spent on CAD, and a lot of tweaking, I’ve got a working robotic tentacle prototype! I used the hand pump off of a sphygmomanometer and a lot of sil-poxy, but it’s working in a rough and ready way. There’s video after the jump below.

I had to cut this one open to fully remove all the core and then sealed it back up. I think the next version will evacuate the core cleanly due to the powder tweaks we made, though. It could also use some revisions to the way it interfaces with the air supply. In the future I’m going to have to run some tests on adhering silicone to various plastics to see what will make for the most solid fittings. The sil-poxy infosheet says polyurethanes are a good candidate, so I might start there.

I owe a ton to Jim Bredt of Viridis3D who, in addition to refining the tentacle design for printing and casting, 3d printed and cast this mold. I wouldn’t be able to do any of this without him.