The Tentacle
An articulated tentacle controlled with 3 motors.
I got inspired seeing some snake-like robot, and I was looking for a way to recreate snake-like movements in LEGO. This is the simplest and smallest result I was able to get. The Tentacle consisted of seven identical modules, with three separate strings going through all of them and fixed only to the top one. Each module included a ball joint, which allowed bending in any direction but to a limited angle, unlike the universal joints which would allow bending at right angles, and a wedge belt wheel which simply held the strings. At the same time, the strings were keeping the whole tentacle together and were pulled or released by three independent motors.
It is probably possible to build a much longer tentacle, but it seemed to get harder to control with increasing length. A short tentacle could be controlled manually by simply attaching the strings to some triangular piece mounted on a ball joint, and tilting it by hand. Since there are three motors required, the NXT could be used if somebody is able to create and algorithm that converts movements e.g. of a gamepad stick to the movements of three strings.
It should also be possible to build a much bigger and sturdier tentacle using the ball joints from the 8110 Unimog set, which would also allow to run a driveshaft through the middle, driving some device at tentacle’s top. Running strings through these ball joints could be a little tricky, but I imagine they don’t necessarily need to form a perfect isosceles triangle.
I was thinking that too. I think it might be more difficult to controll, as one motor releasing or pulling a string to move the arm, but more strings would have to work in unison or at least similarly mimicing movement of other strings, but with a workaround they would add more strength and accuracy. But I have basically no idea.
If I would make this I would use my Ev3 for pulling the strings so I could control it with a gamepad – much more comfortable! 🙂
@Sariel
When I’m building something I’m permanently thinking like “What part will I need next” and “how could I Improve what I have” and searching for parts so that I think it was impossible for me to take pictures of what I’ m building or even posting them on Facebook like you do _ but the reason also could be that I dont really take breaks when building which is why I usually build a model for a maximum of two days.
Hi, I made this tentacle with pneumatics.
http://enthusiastickbuilding.blogspot.jp/2013/09/the-tentacle-with-pneumatics.html
It does not move smoothly like yours…
@Leon Overweel
Cool… 😮
@mees
No, it’s not free.
do you know if robotC is free?
@Leon Overweel
Looks really good, I like the smooth articulation between the joints.
@Kwon8429
With Photoshop.
Hi sariel.
your Image editing was Awesome, Especially Font, Very many kind of fonts, there are all good! question…. How to make it? I am really wondering…
Hey I think we’re on the same wavelength here. I’ve had a prototype a lot like this but a bit bigger together for a couple of months now, but I haven’t had the time to build the supporting structure around it (being a lot heavier mine would probably also be suspended upside down instead of rightside up like yours is.)
Have you seen Festo’s Bionic Arms at all? That’s where I got the idea for mine; they’re pretty cool too. But yeah I took a quick video of my prototype version, let me know what you think:
http://youtu.be/R9YHQg7xHYo
For longer tentacles wouldn’t you just add more strings? If you had six strings, you would probably have much more control as opposed to just three.
Hahaha, the fencing part made me laugh a lot! Maybe you could make some bigger ones and have a duel with someone else…? 😉
@Harley
I’m not going to do that for a variety of reasons, starting from technical difficulties and ending with the fact that you wouldn’t really see anything interesting. My building processes are shown at Facebook, go check it out.
Austron, one of the best knex builders, is doing a livestream, through youtube, where he is building his next knex marvel and I thought it would be great if you considered doing something similar. It would give us a great insight into your builds and processes. /watch?v=MjYk0P8iiWU&feature=plcp
cool!
cool!
But still really cool! 😀
Wow, that’s pretty scary! 😛