The Bootup Guide To Homebrew Two-Stage Tentacle Mechanisms

September 13, 2016 by 42 Comments

What’s not to love about animatronics? Just peel back any puppet’s silicone skin to uncover a cluster of mechatronic wizardry that gives it a life on the big screen. I’ve been hunting online for a good intro to these beasts, but I’ve only turned up one detailed resource–albeit a pretty good one–from the Stan Winston Tutorials series. Only 30 seconds into the intro video, I could feel those tentacles waking up my lowest and most gutteral urge to create physical things. Like it or not, I was hooked; I just had to build one… or a few. This is how you built a very real animatronic tentacle.

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I built this. And you can too!

If you’re getting started in this realm, I’ll be honest: the Stan Winston Tutorial is actually a great place to start. In about two hours, instructor Richard Landon covers the mindset, the set of go-to components, and the techniques for fabricating a tentacle mechanism with a set of garage tools–not to mention giving us tons of real-film examples along the way [1].

We also get a sneak peek into how we might build more complicated devices from the same basic techniques.  I’d like to pick up exactly where he left off: 4-way two-stage tentacles. And, of course, if you’ve picked up on just how much I like a certain laser-cuttable plastic at this point, I’m going to put a modern twist on Landon’s design. These design tweaks should enable you to build your own tentacle and controller with nothing more but a few off-the-shelf parts, some Delrin, and a laser cutter… Ok, fine, a couple 3D printed parts managed to creep their way in too.

bom_graphicIn a good-ol’ engineers-for-engineers fashion, I’m doing something a little different for this post: I’m finishing off this series with a set of assembly videos, a BOM, and the original CAD files to make that beast on the front page come to life. As for why, I figured: why not? Even though these mechanisms have lived in the robotics community and film industry for years, they’re still lacking the treatment of a solid, open design. This is my first shot at closing that gap. Get yourself a cup of coffee. I’m about to give you every bleeding detail on the-how-and-why behind these beasts.

All right; let’s get started.

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Arduino Powered Knife-Wielding Tentacle Will Leave You In Stitches

November 30, 2015 by 31 Comments

Writing articles for Hackaday, we see funny projects, and we see dangerous projects. It’s rare to find a project which combines the two. This one somehow manages to pull it off. [Outaspaceman] is familiar with LittleBits, but he’s just starting to learn Arduino programming. He completed the blink tutorial, but blinking an LED just wasn’t enough fanfare for the success of his first Arduino program. He connected the Arduino Mega’s LED output to a pair of LittleBits which then switch a servo between two positions. A bare servo wouldn’t be much fun, so [Outaspaceman] connected a tentacle and a small Swiss army knife. Yes, a knife.

The tentacle in question is designed to be a finger puppet. There’s something about a tentacle waving a knife around that is so hilarious and absurd that we couldn’t help but laugh. We’re not alone apparently, as this video has gone viral with over 1 million views. It’s almost like a violent revenge of the most useless machine. For the technically curious, the tentacle’s seemingly random motion is analogous to that of the double pendulum.

Our readers will be happy to know that [Outaspaceman] has made it to the Arduino servo tutorial, and is now controlling the servo directly, no LittleBits needed. We just hope he has a good way to turn his creation off – without the need for stitches.

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Printed Tentacles For PCB Probing

May 9, 2015 by 15 Comments

Every hacker workbench has one or more of those “helping hand” devices to aid in soldering and assembly. When it comes to testing and debugging though, it could get tricky if you have to start handling test probes while looking at the meter display or fiddling with knobs on the oscilloscope. Sometimes one has to test a board that has just pads for test points. Or maybe you need to directly probe pins on an IC. Checking multiple signals on I2C, SPI, Serial or USB is not too easy with just two hands. [Giuseppe Finizia] is an electronic engineer at the Scientific Investigations Department of the Carabinieri in Italy. He works as a senior analyst in the Electronic Forensics Unit and deal’s with technical investigations on seized electronic devices. To help him in his investigative work, he designed and built a 3D printed PCB workstation with octopus-like tentacles that provides all the additional fingers needed.

The tool is basically a base with adjustable clamps where the test PCB can be fixed. Around the base, up to twelve articulated “tentacles” can be fixed. Various test accessories are attached to the ends of these tentacles – Alligator Clips for holding electronic parts, IC Hook Clip Grabbers, Micro SMD Grabber Test Clips and some others that he is still working on. [Giuseppe] used  MOI 3D modeling software to design his device, and the files are available on Thingiverse for download. He does warn that printing all the parts, specially the tentacle units, can be quite tricky on a regular 3D printer. He used a ZORTRAX M200 printer in high resolution mode and Z-HIPS filament. However, it may be easier to just use machine shop flexible coolant pipe for the tentacles. This may require some sort of modification to the base mounts and the business end of the tentacles though.

Thanks to [CFTechno] for sending in this tip.

Robotic Tentacles For A Disturbing Haunted House

September 16, 2013 by 9 Comments

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[ivorjawa] is putting on a haunted house this Halloween that we really don’t want to go to. His robot tentacle is already supremely creepy, and we’re assuming it will only be more frightening once it’s covered in fabric and foam rubber.

Each tentacle can move on two axes thanks to four steel cables running through this strange Geiger-esque contraption. In the base of the tentacle are two stepper-motor driven cylinders that take up slack on one cable and draw out another cable. Two of these control boxes, driven by a stepper motor and an Arduino motor shield, allow the tentacle to reach out and grab in any direction. You can check out the mechanics of the build on [ivorjava]’s flickr

On a semi-related note, even though we’re more than a month out from Halloween, we should have more Halloween builds in our tip line by now. If you’re working on one, don’t be afraid to send it in, even if you’re just showing off a work in progress.

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Tentacles And Phalanges Made From Drinking Straws

January 3, 2013 by 8 Comments

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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.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Death Metal Macro Pad

September 14, 2023 by 7 Comments

At “the size of three 60% keyboards (put together)” or approximately one Cannibal Corpse record on vinyl, this beautifully-executed death metal font-inspired macro pad by [zyumbik] may be better off hanging on the wall than hanging out on the desktop.

But let’s say you did have room for the 9-key Deathpad on your desktop. Wouldn’t you just play with the tentacles (?) all the time like I would? Yeah, that’s what I thought. They’re pretty inviting.

So why does this look so fantastic? It’s an SLA print, for one thing. For another, [zyumbik] spent over 1,000 hours designing the thing. Unfortunately it’s not open-source, but you can buy the only other one in existence for a cool $1,000.

Rubik’s Cube Keyboard

Although it doesn’t rotate (yet), creator [_Rudeism] is calling this the Rubik’s Cube Keyboard. Fine with me, though any type of actual rotation would be insanely difficult to pull off. The plan is to do it with RGB LEDs.

The layout is QWERTY-adjacent — the white side is the num pad, yellow has the modifiers, and the other four sides house all the letters. As you might imagine, this uses a custom frame and PCBs. The switches are Glorious Gateron Clears, which definitely supports the blinkenlights planned for V2.

This thing reminds me a bit of of the SafeType™ vertical keyboard, or even [Aaron Rasmussen]’s spherical keyboard. Be sure to check it out in Monkeytype action, where [_Rudeism] manages to pull off about 20WPM. Continue reading “Keebin’ With Kristina: The One With The Death Metal Macro Pad” →

The hack's author performing the operation described at his workdesk, with a separate camera window showing the acupuncture needles being used to touch the board points

Find SWD Points Quickly, No Extra Hardware Needed

January 31, 2023 by 9 Comments

Say you’re tinkering with a smart device powered by a CPU that uses Serial Wire Debug (SWD), but doesn’t mark the testpoints. Finding SWD on a board — how hard could it be? With [Aaron Christophel]’s method, you can find the SWD interface on a PCB within a few minutes’ time. All you need is two needles, a known-to-be-ground connection, an SWD dongle of some kind, and a computer with an audio output. What’s best — you could easily transfer the gist of this method to other programming interface types!

The idea is simple: you wire the ground up, connect the needles to SWDIO and SWCLK, launch [Aaron]’s Python script, then start poking around all the unnamed test points. The script runs JLink software to probe for SWD devices attached to the probes — if an SWD interface isn’t found, it beeps idly, but as soon as the device is detected, your computer will start beeping at you in a lively manner. In this way, you don’t have to re-scan devices manually, solder to any test points except the GND one, or try and hold both probes on test points with one hand – the scanning process itself is hands-free.

Depending on how many points your board has and whether you try to optimize the process by probing points closest to the SWD pins on the CPU, you might hit the jackpot immediately, or you might have to poke around for a minute-two. That said, [Aaron]’s method seems to be the best you can do while remaining relatively extra-hardware-free, and if you want to make it a tinge more permanent, clothespins are there for you.

In case you don’t mind extra hardware – could we interest you in some 3D printed needle probe desks? There’s a wide variety of those, whether you’d like some tentacle-like ones, or ones that make your desk look like like an acupuncture table. Or, say, would you like a more automatic method of finding all kinds of debug interfaces? Then JTAGulator might be what you’re looking for.

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