Tabletop Basketball With Tentacles

Unlike football/soccer and foosball, basketball doesn’t really lend itself to being turned into a tabletop game quite that easily. [The Q] has found a way around that, employing tentacle mechanisms to create a two-player, basketball-like game.

Each player uses a pair of two-axis control sticks and a foot pedal to operate a cable-driven tentacle with a gripper on the end. These are two stage tentacles, meaning that the top and bottom halves are independently controlled. The tentacles consist of a series of laminated foam discs clued onto bicycle cable sleeves. The cables are open in the section they control, and operate in a push-pull arrangement. The spring-loaded grippers are operated by the foot pedals, with a single cable running down the center of the tentacle.

The game looks quite fun and challenging, and we can imagine it being even more entertaining with teams of two or three people operating each tentacle. Add a bit of alcohol to adult players, and it might become downright hilarious, although the mechanisms would need to be beefed up a bit to survive that level of punishment.

We suspect [The Q] read [Joshua Vasquez]’s incredibly detailed three-part guide on two-stage tentacle mechanisms. Combine that with his guide to cable mechanism math, and you’d be well-equipped to build your own. Continue reading “Tabletop Basketball With Tentacles”

A Tentacle That’s A Work Of Art

We all bring our own areas of expertise to our work when we build the projects that find their way in front of Hackaday writers, for instance a software developer brings clever brains to their microcontroller, or an electronic engineer might bring a well-designed piece of circuitry. [Yvo de Haas] is a mechanical engineer, and it’s pretty clear from his animatronic tentacle that he has used his expertise in that field to great effect.

If you think it looks familiar then some readers may recall that we saw a prototype model back in February at Hacker Hotel 2020. In those last weeks before the pandemic hit us with lockdowns and cancellations he’d assembled a very worthy proof of concept, and from what we can see from his write-up and the video below he’s used all the COVID time to great effect in the finished product. Back in February the control came via a pair of joysticks, we’re particularly interested to see his current use of a mini tentacle as a controller.

At its heart is a linkage of 3D-printed anti-parallelograms linked by gears, with cables holding the tension and controlling the movement of the tentacle from a set of winches. The design process is detailed from the start and makes a fascinating read, and with its gripper on the end we can’t wait for an event that goes ahead without cancellation at which we can see the tentacle for real.

If you’d like to see more of [Yvo]’s work, maybe you remember his wearable and functioning Pip-Boy, and his working Portal turret.

Continue reading “A Tentacle That’s A Work Of Art”

From Hacker Hotel 2020: Badges, Sharks, Tentacles, Old-School Hacking, And Much More

The North Sea in a winter storm is a spectacular sight, one of foam-crested waves and squalls driven on the gale. It’s not a place to spend a lot of time if you are a land-lubber, so to cross it twice in a few weeks must mean there is something very much worth seeing on its other side.

More of that exotic cruise ship lifestyle.
More of that exotic cruise ship lifestyle.

But one of the best antidotes to February weather in the European hacker community was Hacker Hotel 2020. Around 350 people came from all the countries of the northwest of the continent to the comfort and hospitality of the Westcord Hotel de Veluwe in the eastern Netherlands, to experience a hacker camp with all the convenience and luxury of a resort hotel rather than a muddy field.

Three days in this environment results in a camp that’s just a bit special, and one that’s very much worth a visit if your range extends this far.

An Upscale Hotel Gets The Hacker Treatment

The Hacker Hotel badge 2020 has many hidden depths
The Hacker Hotel badge 2020 has many hidden depths

Our small party of Brits arrived a day early, on a damp Thursday morning ready to lend a hand with the set-up. Slowly an upscale business conference centre was transformed into a hacker camp venue, with conference rooms turned into lecture halls, lighting and video equipment in place and 3-phase power cables snaking along the skirting boards. A large hardware hacking area was set up in one wing of the building, then the EventInfra people came in and laid out a hacker-camp-grade wireless and wired network that delivered connectivity everywhere. The contrast between the two worlds is significant, but together they make for a unique experience.

One by one, hackers arrived from all points of the compass, bearing crates of the usual cool stuff. An amateur TV satellite earth station, a brace of oversized delta 3D printers, a coin-pushing game that’s familiar from other camps. And smaller projects; little roving robots, indoor-sized multirotors, and several crates of outdated Chinese photo-frames that it’s said can be hacked to run a Linux distro.

This is the lifeblood of a hacker camp, but of course the signature piece of hardware for any hacker camp is its badge. In this Hacker Hotel 2020 didn’t disappoint, with a beautifully designed Ancient Egyptian-themed badge that concealed an array of puzzles across multiple levels. We’ll cover the badge in detail in a separate piece, but suffice to say that it is something of a tour de force. For now let’s jump into all of people and activities on offer at the con.

Continue reading “From Hacker Hotel 2020: Badges, Sharks, Tentacles, Old-School Hacking, And Much More”

Two-Stage Tentacle Mechanisms Part III: Putting It All Together

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:

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Nothing like a fresh batch o’ parts.

Design Files

  1. The Almighty Bill-o’-Materials
  2. Vector Drawings for laser cutting
    1. DXF files pre-offset (0.003″)
    2. DXF files original
  3. STL Models for 3D Printing
  4. Original Tentacle CAD Model Files
  5. Original Controller CAD Model Files

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.

Continue reading “Two-Stage Tentacle Mechanisms Part III: Putting It All Together”

Two-Stage Tentacle Mechanisms Part II: The Cable Controller

A few weeks back, we got a taste for two-stage tentacle mechanisms. It’s a look at how to make a seemily complicated mechanism a lot less mysterious. This week, we’ll take a close look at one (of many) methods for puppeteering these beasts by hand. Best of all, it’s a method you can assemble at home!

Without a control scheme, our homebrew tentacle can only “squirm around” about as much as an overcooked noodle. It’s pretty useless without some sort of control mechanism to keep all the cables in check at proper tension. Since the tentacle’s motion is driven by nothing more than four cable pairs, it’s not too difficult to start imagining a few hobby servos and pulleys doing the job. To get us started, though, I’ve opted for hand controllers just like the puppeteers of the film industry.

Enter Manual Control

Hand controllers? Of all the possibilities offered by electronics, why select such an electronics-devoid caveman approach? Fear not. Hand controllers offer us a unique set of opportunities that aren’t easy to achieve with most alternatives.

Continue reading “Two-Stage Tentacle Mechanisms Part II: The Cable Controller”

The Bootup Guide To Homebrew Two-Stage Tentacle Mechanisms

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.

Continue reading “The Bootup Guide To Homebrew Two-Stage Tentacle Mechanisms”

Arduino Powered Knife-Wielding Tentacle Will Leave You In Stitches

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.

Continue reading “Arduino Powered Knife-Wielding Tentacle Will Leave You In Stitches”