Single-Stage Tentacle Mechanism Workshop Edition

“But you may find that with a proper introduction, the subject will catch you.” –Joseph Campbell

Back in 2017, I threw my first hardware workshop at the Hackaday Supercon. It was my take on a “crash course” in functional rapid-prototyping using a laser cutter, and folks loved it! This year, I did some refinements and took it back to Supercon with not 13 but 20 kits.

The Why

Even in 2018, laser cutting seems to be deeply overshadowed by 3D printing. Admittedly, hefty CO2 lasers are dangerous, expensive, and they take up lots of garage space. Consequently, scarcity seems to hold back an open discussion on the variety of techniques that you can use with them. My workshop was a first-take to get folks excited about laser cutting in the hacker and hardware-prototyping community.

I’m an engineer by training. As a result, I seem to have acquired a taste for function-with-form over form alone. For this reason I opted to introduce folks to laser-cut Delrin parts. Delrin is far more ductile and far less brittle than our other favorit go-to material: Acrylic. Furthermore, with a laser cutter that has at least a 60-watt output, Delrin cuts beautifully, vaporizing to leave a buttery-smooth surface finish that’s free of burn marks.

Delrin also nicely accommodates press-fit pins, bearings, heat-set-inserts, and bushings, making it excellent for prototyping when mixed with a variety of stock parts. I used a mix of these stock parts to give folks a taste of various elements that they could apply to future projects.

With a little luck, this project could be that “proper introduction” that catches the hearts and minds of other aspiring engineers.

Your Turn

I’ve attached the instructions and BOM with part-file links. May they serve you well on your animatronics-building adventure.

The instructions are split into 3 parts: the controller, the tentacle, and the integration of the two. Take your time with this one. This build takes students about 3-4 hours with some guidance, but also keep in mind that laser-cutting these parts can take a few hours. Also note that one part (the flexible shaft) has a lead time of up to 3 weeks since it ships from China via Aliexpress.

Feel free to drop me a note if you’re puzzling your way through building your own!

Source Files