A little bit of online curiosity often leads to nothing but pictures of cats or an update on the weather. But sometimes that same curiosity can, like it did with Hackaday contributer Joshua Vasquez, spiral into the careful construction of an animatronic tentacle. And this likely would never have happened were it not for the stumbling on upon the Stan Winston tutorial that provided inspiration to the Hackaday monster.
The hackaday tutorial goes into great depth about the mechanics, some of the math and ultimately how its creator was able bypass a lot of the trickier elements found in the Stan Winston video above with Delrin as a source material, a laser cutter and some 3D printed parts. But when you are dealing with the creation of an animatronic anything the moving parts need to be considered as well.
Wanting to allow for four degrees of freedom along two tentacle stages, his design needed a mockup phase and a lot of preplanning so that “in an ideal world, tugging on each stage’s cable would form a perfect arc that decreases in diameter the more we tug.” In time, it soon became clear that not all of the parts (mainly due to the expensive nature of them) could be sourced in a way recommended in the original Stan Winston video so off-the-shelf parts needed to do. For example, Pololu motor hubs (often found in desktop 3D printers) were used with an extra Delrin plastic cut plate to hold the control cables in the right spot.