Welcome back to the final chapter in our journey exploring two-stage tentacle mechanisms. This is where we arm you with the tools and techniques to get one of these cretins alive-and-kicking in your livingroom. In this last installment, I’ll guide us through the steps of building our very own tentacle and controller identical to one we’ve been discussing in the last few weeks. As promised, this post comes with a few bonuses:
Depending on your situation, some design files may be more important than others. If you just want to get parts made, odds are good that you can simply cut the pre-offset DXFs from the right plate thicknesses and get rolling. Of course, if you need to tune the files for a laser with a slightly different beam diameter, I’ve included the original DXFs for good measure. For the heavy-hitters, I’ve also included the original files if there’s something about this design that just deserves a tweak or two. Have at it! (And, of course, let us know how you improve it!)
Ok, now that we’ve got the parts on-hand in a pile of pieces,let’s walk through the last-mile tweaks to making this puppet work: assembly and tuning. At this point, we’ve got a collection of parts, some laser-cut, some off the shelf. Now it’s time to string them together.
Everyone wants their prototypes to look polished, as opposed to looking like 3D-squirted weekend afterthoughts. The combination of Delrin and a Laser Cutter make this easy, especially if you learn a few tricks-of-the-trade that will make your assemply pop, both functionally and aesthetically.
If you’re just getting started in this domain, let me introduce you to two classic techniques for laser-cut prototypes: puzzle-piecing and the T-nut-slotting. While these techniques are tried-and-true, I hope, fearless reader, that they’ll leave you hungry for something cleaner, something more refined. If that’s the case, read on!
He human hand is one of the most impressive pieces of machinery – biological, mechanical, or otherwise – that you’ll ever lay eyes on. With two dozen degrees of freedom, the hand can gently caress the most fragile flower petal without bruising it, or beat a hammer into an anvil with tremendous force. Simulating the human hand, however, is quite a challenge that requires dozens of servos and complex mechanical linkages. [Tomdf] over on Instructables is able to create hands, tentacles, and other weird biological contraptions using spring-loaded drinking straws and custom-made 3d printed joints.
[Tomdf] got the idea for drinking straw phalanges after seeing a few 3D printed drinking straw connectors meant to be used for creating 3D objects out of disposable plastic tubes. After designing a new spring-loaded joint for drinking straws, [Tomdf] is able to add a few lengths of thread to serve as ligaments to control the segments of drinking straws. It’s a similar setup to the horrible demon spawn we saw at Maker Faire last year, but far more extendable for any project that might pop into your head.
You can check out the drinking straw tentacles in action after the break.