Building a better Doc Ock Tentacle

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We’ve all seen Doctor Otto Octavius or Doc Ock, in the Spiderman comics and movies. Dock Ock has four tentacles and four of his own limbs, so that makes nine in total, and that’s the same as an octopus.
Lots of cosplayers have made Dock Ock cosplays, including Adam Savage, although mostly those tentacles are in fixed positions or supported with strings. So this time I’m going to try a different approach, using six actuators in each segment of the tentacle.
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[@JayFolipurba]

What I think is especially fun about this, is that the tentacles from the movies also have a triangular cross section and seeing how this moves, this might actually be the way to go about it

[@davidmartensson273]

And in an old comic where they showed some schematics on how they imagined they worked, while the exterior was tubular, internally each segment was drawn to have 3 pistons in a triangular pattern, quite a lot like this build, just using a different type of motion to get it done.

[@rommdan2716]

​@@davidmartensson273 Lots of people have put lot of thought into cómic book logic

[@n.d.378]

I clicked this video and was "if they aren't triangles ima be mad" ...low an behold, they are. lol

[@riohudson9612]

Shorten the struts of each segment. Reinforce the motors. Augment with hydraulics. Oh, yeah. It's all coming together.

[@julianrubinstein8499]

Ah yes 4+4=9

[@similar_username]

Yeah, it shout be 4 limbs, 4 artificial limbs, and 2 heads. So 10 really.

[@Love_N_Let_Live]

​@@similar_username 2 heads? Whut?

[@Love_N_Let_Live]

Yeah, I'm not sure how he got an odd number. I'd understand another mistake maybe, but to add even numbers to get an odd one is a first for me. I feel like a genius now, because this man is damn smart. Gotta take what you can get, I guess. This is our moment. 🧠🤓

[@TheLukemcdaniel]

@@Love_N_Let_Live Run it by a teenager. They'll get it real quick...

[@Spiker985Studios]

​@@Love_N_Let_Live Doc Ock had his own brain, and the tentacles had a neural link which was supposed to partially think for itself, and interpolate his thoughts to the tentacles It's why he talks to them

[@ShonicBurn]

For the second prototype feel like a smaller version of each segment to reduce the strain on the base might make it look even more like a real tentacle arm.

[@Harlequin_Actor]

Or making the base out of stronger material and then moving to lighter material as you went further out

[@marcobaldanza2332]

go big or go home!

[@nos9784]

​​@@Harlequin_Actor nah, tapering is better. Materials have limits, geometry has... later limits :D The strain is the product of load and lever. Increasing the diameter linearly with the arm length (=lever] means the base has to handle the same useful loads as any element. The structural loads (weight of the arm itself) add up, though, so the diameter should increase faster than linear.

[@jakeg6172]

I also was going to suggest tapering segments, thank you for getting there first

[@nos9784]

@@Harlequin_Actor i guess it would be best to do both- taper and build them progressively lighter.

[@kevinbeefchips]

can we appreciate how impressive real tentacles from octopus and squid and such are. To have the degree of flexibilty while still retaining strength is ceaselessly amazing

[@skullthrower8904]

Sure why not

[@justinmccleary423]

They are really alien creatures tho all the cephalopods are just built different from all other creatures even in all our oceans and bodies of water what with some being able to camouflage themselves with any surroundings, change skin textures, mock certain animal shapes, and just overall intelligence. It’s just other worldly tbh.

[@xenicmark]

Biology of crazy. Even the most basic organisms can be incredibly complex.

[@artempozdniakov2850]

That's some biology for you. Invertebrates muscles are actually crazy. Heck, all biological "actuators" are. Google 'sarcomere' and share your thoughts (that's basically the modular molecular motor assembly which is present in pretty much any muscle of any creature. It's really power-hungry, but immensely strong and, duh, stackable) With cephalopods there is this quirk: their "limbs" don't have any skeleton inside, pure muscle, some blood circulation system and nerves. This plus their rather tough skin for said muscles to latch onto gives them that crazy strength. Wanna go further? Go full exoskeleton, get all from biological muscles, become an insect.

[@smokill91]

you SIMP for mother nature. im with ya

[@kanadezosGT]

Implementing inverse kinematics for the end effector plate would be a very interesting follow-up!!!

[@addisonwoods9367]

it would be a good opportunity to make a video on the inverse kinematics of parallel mechanisms!

[@matthahne]

I bet that would get very tricky, because it's under-constrained. There are a lot of positions that top plate can be in where there are multiple ways to get there. So when you go to solve for joint angles, you get multiple answers. Picking from among those answers adds a new wrinkle.

[@igorordecha]

@@matthahne thats why we have random number generators

[@edsilver]

@@matthahne you could use something like FABRIC, which works for systems with multiple solutions.

[@Connor_McCann]

@@matthahne Actually no, parallel manipulators are very easy to solve the inverse kinematics. The forward kinematics are where it gets complicated and there are multiple solutions. It's sort of the opposite of a serial manipulator arm. For a typical Stewart-Gough platform, you basically just decide "I want my platform here," which tells you where all six attachment points will be in space. You know where the six anchor positions are on the base, and you just need to compute the length between those six pairs of points to calculate the actuator lengths. This implementation is a bit tricker due to the extra links he's stuck in mid-way to expand the workspace size, but it should still be possible to work out a one-to-one solution, I believe.

[@apocriva]

That's really cool!! One relatively simple way through code to add some organic-ness to the motion would be to propagate the input to each segment with a delay. So, for a tentacle-y feeling, pulse the input through the base segment, then a slight delay before the second, then the third. If propagated in the other direction (tip first, then mid, then base) it would probably look more like a snake, where the head is making a decision where to go.

[@antonliakhovitch8306]

In the film, Doc Ock's tentacles DO move in that snake-like way in some scenes for precisely the reason you describe! They want to imply that the tentacles are making all the decisions, so they have the motion start from the end effector so it looks like a "head"!

[@HarkerAu]

This is exactly what I was thinking!

[@emkasCG]

Damn I was gonna suggest that, that's basically what we do in 3d animation.

[@Aurich88]

Further showing that Dr. Octavious' fusion demonstration really glossed over the robotics miracle of his tentacles. Great video, really can't wait for the next version!

[@BenHeckHacks]

I like how they fixed that in the Spider-Man game by having Doc Ock's research be about prosthetics.

[@arsarma1808]

Robotics, Artificial Intelligence, Fusion Power, man machine interfacing. Any one of which would revolutionized our society and he was using all 4 in one demo.

[@andybrice2711]

Look into using flexures rather than pivots. It should be lighter, and the springiness will give a lot of inherent structural integrity. I've had good results combining PETG with spring-steel inserts and elastic.

[@jfolz]

Was thinking something similar, possibly with the servo pulling the center to bend it.

[@tristanwegner]

One could also tune these to get a pretension that the tentacle stays upright without any strain on the servos in the default position. So the servos at the bottom would actually pulling down for some moves, instead of just resisting gravity less, as it is now.

[@tomfoolery2913]

Yeah and then using wires to control the placement of the tip, like how most mechanical hands work

[@SasteJugaad]

Amount of servos this guy uses in his projects is mad. Respect ++

[@MartinPittBradley]

And I recall him having bearing and 3D printing sponsors, but servos? James might be a whale for AliExpress

[@guerrillaradio9953]

Imagine the peak current draw 8o.

[@Cristopher.C]

I for one cant get enough of that sci-fi servo sound :Q__

[@Skyentific]

Really great video! And thank you for mentioning my work!

[@milou66]

Doc Ock quite often uses his lower tentacles for stability, so that might help with the weight issue. Also, I would say it's already a work of art, even sans LEDs.

[@GeorgeCowsert]

The weight issue still applies to the individual tentacles. He uses his lower two for stability so that he doesn't flip over when he lifts something heavy. Strain will always exist. It's merely a matter of knowing your limits.

[@elijahbutterfield4869]

I too use my lower testicles for stability.

[@coalthedergsune]

@@elijahbutterfield4869 r/cursedcomments

[@JakHart]

6:44 It's uncanny to me, how this setup looks somewhat lifelike as you operate the joystick. Yes, it's moving mechanically, but it does it with flow, it feels alive because of that.

[@finndriver1063]

Could you change the kinematic model such that each segment starts moving a bit before the one below? I think that might give it a slightly more organic feel, like it's curling into each movement rather than leaning.

[@loganhollows]

This is one of the coolest projects you've done in quite some time! Love it! Keep it up

[@iamkian]

I agree 100%

[@tristanwegner]

I am really surprised how organic this looks, especially with some segments inverted. But there are so many more ways to move such a system. Probably a reason why octopuses have such a large brain. This would also be an interesting movement problems for machine learning to improve in a simulation.

[@JacobShepherdEngineer]

I'm always impressed by the scale of the projects you put out. It would take me months to design and build what you do in a week.

[@stcattc]

No other channel gets be as excited for an upload as James!

[@NicholasSkvarla]

For the macro positioning, you could use a parametric spline function. As you know the length of each section, you can easily calculate the 3d slope at a given point along the curve, which will give you the normal for the platform that you can feed into the inverse kinematic function.

[@ianmilham7397]

I’d love to see a movement that each stage mimics the motion before it, but with a slight delay. You could get a really cool snaking effect with it

[@joe1205]

It's amazing how you've managed to make something so mechanical seem so organic and alive!

[@Theballonist]

Very cool, I haven’t seen a project like this achieve such interesting motion so quickly before.

[@hazonku]

Amazing work, James! I always love the complexity of movement you manage to get out of simple servo movements & a bit of maths.

[@megabrawndo]

With three sections I would say it really is more like a worm. The cords even look like the digestive tract.

[@inventorbrothers7053]

Honestly...you are a genius! You're my inspiration for being at a STEM college right now! Thank you for making such cool stuff!

[@osamarabee3927]

man , i respect you soooo much for such projects cannt believe the time and effort put to this all my respect

[@insaneninjabunny]

See, I have the oddest feeling that he’s gonna build a whole human, and keep it open source, so we can all build our own.. which.. I’m down for.

[@TimeTravelingFetus]

catgirls

[@CodeManMike]

One of the best designs you have made! So amazing to watch!

[@BenHur872]

Really enjoyed this one. Look forward to seeing the idea develop

[@davidwilliams7094]

That's awesome! Can't wait to see the next version.

[@alvinandreasson136]

Literally the coolest robot-building video I have ever seen! So thrilled for part 2!

[@thehumblefactory]

This is a super interesting design and implementation. I wonder if you might get quite a bit higher ratio of bend per segment by doubling the servo assembly on both the bottom and top of each segment -- basically, you would get twice the extension and compression for each segment, without adding any length, so even though your weight of motors would increase, you would still probably get a tighter radius of bend in fewer segments. As always, you're doing an incredible job pushing the edges of what's possible - I always love sending your videos to my Industrial Design university students, it's a great kick in the pants for them to just try something.

[@sethbaus]

You have an amazing mind. The speed at which you come up with new ideas and bring them to fruition is so amazing. You inspire me to learn about computer code, and how to program. You have such a vast knowledge of computer programming and electronics. It’s very impressive.

[@webbot15]

Would love to see how it looks if the middle section was delayed 100 milliseconds, and the top delayed 200 milliseconds. OR if the top one responded first, then middle, then bottom. I think you'd get some really organic motions.

[@AnimilesYT]

When you mentioned independent control of each section I started to think about ways to have more control over each section. There are 3 joints between the palm of your hand and the tip of your finger, so maybe it would be possible to have more independent control by controlling it with your fingers? Maybe you could use 3 or 4 fingers to control multiple directions. A device to accurately determine the position of each joint of your fingers may be a challenge though. It would probably require some kind of glove. Maybe with strings or a hydraulic system? One of the problems I currently see is that finger joints are rotational, so there isn't linear control for extension or retraction. Therefore horizontal movement and making the arm longer or shorter wouldn't be easily achievable with finger control. The thumb has a lot of control, so maybe you could have 3 points in space to switch between rotational, horizontal, or vertical motion? Like, you move use your thumb like it's one of the sticks on the controller. But if you have it in the bottom right you control horizontal movement, in the bottom left you control rotational movement, and at the top you can control vertical movement. Then you can also mix those types of movement by having your thumb in-between the positions. It sounds like an interesting way to control an arm, but I also expect it to have a steep learning curve 😅

[@VileProject]

In order to reduce the stress on the bottom tiers, you should make each tier slightly smaller than the last. This'll reduce the over-all weight as well. This also will help it look more similar to the source material.

[@gavin5410]

That worm motion you mentioned would look really cool with 6 or so joints, i can imagine a pulsing motion periodically moving from the base of the tentacle to the tip, even when the arms are just still, it woyld make them look so full of life

[@H34...]

Cool, reminds me a bit of your exoskeleton project. I expect you to rock the final build along with doc ock's spectacles.

[@theperfectbotsteve4916]

no its 8 limbs what would be the 9th wait a minute no no no nooooo

[@Love_N_Let_Live]

He must have watched the X rated version movie. That's not Doc Ock, that's Doc Cock.

[@absalomdraconis]

But there's _two_ options, so it would still be 10!

[@soulsyrup]

i am begging for a 2.0 of this!!!! absolutely mind boggling

[@nicolo.lazzaro]

Great one James! Very much looking forward to this project development

[@cluckyduck7029]

You should have the sections taper, get smaller and smaller towards the end. And you should definitely do a version with twisting. And more pronounced movements, wider range, more extension, more compression, more bending. So cool man. One of the top channels on KZbin. Always fascinating. Thanks.

[@davidmartensson273]

Twisting is not really required if each section can move in any direction, you would only need rotation at the end for the gripper. And adding the rotation will add complexity and mode springiness in the movement, especially if you do not use some rim bearing. A central shaft would make it quite a lot less durable and wobbly.

[@_ninthRing_]

Impressive use of taking an existing technology & putting it to an unintended use - the essence of invention. Looking forward to v2.0.

[@itsjjbones]

This looks really fun to use

[@dacolib]

I think it would be cool to try using pnematics for something like this! You can make it stretch and contract with very light materials! Not sure how the tubing would work though

[@davidmartensson273]

The original comics uses something that looked like pistons. But they could probably be linear actuators in a shell. The problem otherwise with pheumatics is piping and valves, and you would probably go hydraulics since pneumatics using air get more springy, and would bounce a lot more.

[@hiroshrosh3535]

you could make the bottom servos beefier and make each stage successively smaller and lighter, because it only has to be able to move what is above it, a bit like a pyramid

[@bertusackerman]

What I see as an interesting use case for these three stages (maybe 4) is a flashlight/floodlight that follows a target that's been picked up by some sort of sensor-array. That way your security light doesn't just come on and flood the area, but roughly follows a target around - creating a much bigger feeling of "being followed" rather than just the whole yard lighting up...

[@d-emprahexpects849]

Insane creation there. I couldn't understand anything or the mechanical, electronic or engineering side but I thoroughly enjoyed this contraption coming to life. Well well done!!!

[@emanuel.is.suffering]

"... Dock Ock has four tentacles and four of his own limbs, so that makes nine in total ... " written in the video description. But why nine?

[@kiwigaming09]

Your forgetting the "third leg"

[@MyMainTV]

This is so cool, more of this please

[@heyitsthatdude17]

Wonderful project as always James

[@BrockCheddar]

Great work as always, James!

[@NeilABliss]

Peristaltic motion worm is a great idea, you wouldn't even need the switches ,, you could just program the inverse of each section loop wise after each move.

[@Marshaze1]

always building the coolest stuff!

[@tsc_blt]

This is the beginning of something amazing. I hope other KZbinr do this too so the collaboration can push the idea further.

[@BeckyStern]

Love it! Thanks James 😀

[@drednaut6969]

I feel like if you made 4 or 6 of these 3 section tentacles and put them on rotators connected to a platfrom, they would work quite well as legs (especially with the added supports you mention) because that heave/contraction motion could help with the clearance required to move a leg. Nice work!

[@matthewbadger8685]

I would love to see him build a robot like those from the Matrix movies. The eyes could be replaced with sensors that allow it to navigate its environment using some form of AI, like what boston dynamics use.

[@RomanNumural9]

This is really cool! The best one I've seen so far! If you had 20 of these made really small and stacked together it would even look like the tentacles. At that point you might need a new way to control them though

[@crazyblazeX]

Awesome, you inspired me to work on a new cosplay project! Gotta buy a bunch of servos now 😅

[@eugenvonderkipe6031]

cant wait for the complete build

[@ThaBullykid]

Great concept! I think you should move the cables to be in the middle of the tentacle. It does not only look nice, it also has the benefit of moving al lot less than they would when kept on the outside of the tentacle.

[@nielsvdmarel]

such a cool project! really enjoyed this video!

[@r5bc]

We need version 2 asap! 😊 Who agrees with me?

[@lloydsvoid]

Such an awesome build! I would love to see what it looked like wrapped in cloth

[@MrPatrik775]

Good and nice job ! I would like to add that most probably every next segment of the tentacle should be scaled down to reduce the weight and force at the end of the tentacle itself. Like branches attached to the main trunk of the tree.

[@georgeaura]

I would really like to see this upgraded in the way you mentioned it could be.

[@keelan270]

This is so cool ! Looking forward to the next part of this series!

[@jtjames79]

9 in total? Umm... 🤔

[@the_omg3242]

The guy's pretty good at building robots. He doesn't have to be a math wiz. ;^)

[@danatronics9039]

🍆🤔

[@fred1369]

Can't wait to see v2!

[@AB-Prince]

not sure how to calculate the position for this type of stewart platform, but I know if you use linear actuators then it's fairly simple trigonometry

[@ZenHulk]

I have been trying to build a Stewart platform forever, but i could never find any help on programming anywhere. Thank You for your videos, in case no one has told you lately.

[@HaysonTM2]

You could give the sections their own independent rotational movement if you used small electric hub motors mounted at the base of each structure, then instead of have a long central bar that spans each entire section you could have a smaller peg that slides the a bearing on the top of each section that sits flush with both section's surfaces.

[@river1711]

Please do the second version I’m super excited!

[@hatimalmaghrabi7034]

We need the version 2 for this 👏🏼👏🏼👏🏼

[@tvheadd]

Since the inside of each section is more or less hollow, it might be possible to add a servo within the top side of each segment that stands proud and connects to the base of the next segment above it, giving each section a kind of "wrist turn" motion. Granted it would be huge loads of math to process, but the additional flexibility and freedom of movement might be really neat!

[@TheTwistedTraceur]

more segments like you said, but smaller could make it very articulate. great video!

[@romanhunter9116]

I’m really interested in this new project and I would really like to see how a version two would work out.

[@ransombot]

Bézier curve might be a fun way to control it could constrain them to the robot's constraints and use them to form the shape.

[@brenopereiradealencarbarra5285]

Amazing work

[@billieslang5864]

WOOOWWWWW I AM SO SO HONORED TO HAVE A LITTLE CAMEO IN THIS! Means a ton to me, even its just four seconds 😅😅 thank you so much! Also, your build is incredibly impressive, god damn

[@Apossuman]

I say leave a hole or tube in the center for running the cables. Cant wait for the next version!!

[@jakem3422]

How are you powering all the servos? Also, I'm curious what you where pulling in amps?

[@thecrazy8888]

Man your good... I just can't wrap my head around how you translate all that motion into code you can control with those sticks.

[@turtlebunch2]

would a thin anchored fiberglass rod down the middle be a good way to help take the strain off the bottom servos? or would it just add unnecessary strain to everything?

[@Big_Un]

Awesome. Thank you! How about a hole in the center of your base plates to route all your wiring?

[@sam289]

Fascinating. Not an engineer, so feel free to haze me hard if I say something stupid, but I could see pneumatic as being really good for this. If you had a central highly pressurised tube with connections at the base of each section, you could drive the stewart platform with pistons connected to solenoid controlled valves. Letting the pressure control the movement of the mechanise. I'd also sagest having each segment stacked around halfway (or whatever mathematically works) along the former, allowing a smother, more tentacle like movement due to the fact that this would allow the mechanise to efectivly counteract the angels necessary for a stewart platform to work. However, I have no idea how complicated this would be to get working right, if it's even posable, and if there would have to be some kind of mechanical stabilising ring that would lock the bace of each pistons position ,of each segment, to a parallel planer position to the base segment, no matter the place it holds in the chain. You could also use the expanding of the pressurised tube to help support the mass of the mechanise, having bracing rods paced on universal joints halfway along each piston and utilising the force exserted by the tube to hold them steady. This, I think, would solve the problem with the servos lower on the chain being under more stress and allow a more natural movement, as well as, since you would be using pistons, remove the problem of large amounts of joints coursing wobble. Not an engineer though, so just some plebs thoughts.

[@lee2952]

this is so frickin cool!

[@guyinarobe228]

I've looked for years, thank you.

[@Big_Un]

Do you have a video of your joystick controller build? I've looked through your past videos but haven't been able to find one.

[@Rygoat]

This unlocked a memory for me, If you ever wanted inspiration for a skin for it Try checking out an Australian kid's show from the 90's called "Lift off" The whole show was a fever dream, but outside of the lift there was a living plant that was basically a tentacle with an eyeball on the end. I did a quick search and apparently the plant was called "Beverley"

[@whimbur]

You could probably reduce a lot of weight by taking material out of those upper plates, to reduce strain on the servos and add more sections

[@matthewmccalister5594]

:o That is amazing!! Damn this opens up so many possibilities and it is still (relatively) simple!!

[@raftsail]

Awesome! Develop this project! It will be very cool!

[@HCivicFg2]

Absolutely want to see v2. I beg for no more than a years wait.

[@anismokadem972]

Hello, i'm working on a project to control an inverted rotary pendulum with the dc motor voltage as input and the vertical pendulum angle as outout. Any tips for designing the controllers and wothits implementation?

[@mrheisenberg83]

This looks awesome. One problem I see is controlling four of those at the same time, it might be a tad confusing with all those reverse switches. Other than that I think a hole in the middle for the cables to go in will be a nice last step for cleanup. Looking forward to version 2.0.

[@guerrillaradio9953]

It looks like something which could be refined into a robotic arm with possibly enough dexterity to replace lighting and perform other ceiling work like hanging drywall in a safer, faster way from the floor.

[@mograms]

Mesmerizing!

[@rolfathan]

The organic movement on this is so good.

[@raymondrice1360]

I was 7th to like and because of that I just wanna say that I love this man’s creations; ain’t nobody do it besides him and I only with the best for you and thy near future ❤

[@stalnos3581]

That’s actually so cool