This Expanding Mechanism is Crazy Clever

[@williamcastille4193]

Back in the early 90's this mechanism was used to create an "Automatic" gear on a bicycle as it had this mechanism spring mounted and used the torque placed on the pedal to reduce the diameter of the drive gear.

[@mimoslavich6639]

When I saw it Iwas like ummm couldnt this be used to make an automatic gear system, and there was your answer.

[@donalain69]

@@mimoslavich6639 LOL.. Same me

[@donalain69]

What was the reason why this wasn’t continued after the 90‘s? Looks quite superior to stacking different sized gears next to each other.. and would eliminate the gear switching problems..

[@ajsparx4133]

There's a mechanism called a variable transmission (I know its used in mopeds) that this reminded me of. It's basically two bowls spring loaded together at the base like this )( When the speed increases, the centrifugal force pulls the pulley apart )-( so it becomes a smaller diameter pulley system. Different mechanism, but same idea behind it.

[@donalain69]

@@ajsparx4133 if I understand that right that would be a transmission that automatically adjusts to speed, right? Sounds like a high tech moped...

[@3DPrintingNerd]

That mechanism is gorgeous and I love that you've modeled and 3d printed it. It's way easier to understand once you see it in motion in the real world.

[@JonathanScruggs]

I predict a super sized version coming soon. :P

[@MakersMuse]

Ohh a huge one would be insane!

[@pavellelyukh5272]

@@MakersMuse Dude the locksmith lawyer will not be impressed. A magnet lock can easy be hacked using a magnet and then rotating the wheel by hand. You need to connect it to a pin locking mechanism which releases the wheel when it begin rotating when the correct key is inserted that would need to be part of the gear key. Also making an organic tooth path and hiding the teeth under plastic will mean you'd have to capture the dimensions of the regular key and the gear itself.

[@AhsimNreiziev]

@@pavellelyukh5272 You forgot that this was a puzzle box, not a lock to secure valuables with. The Lockpicking Lawyer deals with the latter, not with the former. In other words: concerns he would raise are entirely irrelevant to this video.

[@pavellelyukh5272]

@@AhsimNreiziev actually locks are puzzles. Magnets aren't because the effect is too global. Imo a puzzle requires the manipulation of objects in 3-6DOF to work so unless you use a extremely advanced magnet with selective polarity you'll basically only have 2DOF puzzle

[@bloodwolf2609]

as an Industrial designer I can say that the mechanical movements book is extremely worth the purchase

[@julienmauguin3214]

I bought this book too some days ago and it is an amazing source of inspiration

[@harpereverett3300]

Purchased immediately after hearing it

[@GollumBeetus]

I’m a junior in college for Mechanical engineering technology and mechatronics. Any tips on getting a internship

[@EmilBjrn]

Since it's out of copyright, you can find all of the movements online if you search for the title on Google. It's a cool site to click through from time to time.

[@cvoisineaddis]

The website also has some flash animations of some of the mechanisms.

[@SageSylvie]

507 Mechanical Movements is just a gold mine that needs to be explored on this channel.

[@cameronmalchow7597]

I've seen this mechanism used for expanding tables. The ones that spin and have the leaves come from underneath and then lock in place. Very satisfying design.

[@dimapiwa]

That's exactly what I want to do myself one day. Hopefully author will take a look at this comment and will try creating a 3d printed expanding table so we can try this ourselves. Probably others will proceed with the bigger versions of it 😅 Anyway, a great video there! Thanks a lot 🙂

[@chrisjones3733]

Yeah, the Fletcher Capstan table for 50k. Its pretty amazing though

[@86abaile]

The expanding pulley design is used in the fletcher capstan table.

[@MakersMuse]

That table is a work of art! I think it might use some elements of this mechanism but it's also far more complex with the inserts that fill the gaps.

[@therealpanse]

ahhh... i wanted to say that.

[@CapApollo]

iam 4 hours late..

[@tye2876]

Late also, I wonder what other mechanisms go into the table to get the pieces to open wider then close to accept the wedges moving up.

[@therealpanse]

@@tye2876 I'd expect some helical tracks, some parallelogram to move them... well... parallel. Also maybe some springloaded detent to keep everyting in place.

[@TheWiseTorsk]

"Hexagons are the Bestagons" -CGP Grey

[@Dragon-xd9em]

All hail hexagon

[@anuragneelam8527]

@@Dragon-xd9em hail! hail!

[@AquaB33]

Hexagons ARE the bestagons Cgp grey is great :)

[@carbonbeaker409]

@@AquaB33 not really, it kinda six to be them(the hexagons.)

[@Averymoasycreek]

@@carbonbeaker409 Blasphemy!

[@the.SteamingVegan]

Can I just say, as someone who has never done any engineering, I find this fun, fascinating, and approachable! Super cool stuff

[@KTPDAILY]

you and me both --- we can learn anything!!!!

[@julio709]

Why does this guy look so friendly and kind? And why do I feel in 2001 looking at his face?

[@benjaminh.morgan3193]

Probably cause he looks like Spencer from iCarly?

[@xtankhillx7970]

This mechanism reminds me of a Centrifugal clutch that expand when torque is applied to grab an outer cylinder

[@JustCallMeChad]

I had the exact same thought when watching the vid, and came to say the same thing.

[@GuardianAngle93]

I'd swear it's the clutch on my trimmer

[@irishmick4278]

That's the first thing that comes to mind.

[@stephanied9331]

Added this same comment then wondered if I was the only one.

[@JesseSchoch]

worth mentioning this is how a lens aperture iris works. I used this type of design on my milling machine to lock the spindle via it's splines.

[@allhumansarejusthuman.5776]

Very cool!

[@frogz]

exactly what i thought when i saw it, its inverse of it

[@neilbajaj503]

Hi Angus, this this expanding pulley design was used in the design of an underactuated robotic finger in this academic paper: Underactuated Gripper That Is Able to Convert from Precision to Power Grasp by a Variable Transmission Ratio (Spanjer, Balasubramanian, Dollar & Herder, 2012) The finger has two joint both actuated by the same tendon, which passes over a pulley at each joint. By changing the size of radius of the lower joint's pulley, the stability of the finger tip force and grasping capability of the finger could be changed while still retaining some of the major benefits of an underactuated finger.

[@make.anything]

Another masterful mechanism Angus! I wonder what kind of funky stuff you could do by using different shaped slots for each pin :0

[@MakersMuse]

All sorts of funky motions! I'm definitely gonna keep experimenting

[@gamingforlive2150]

there have been tables using it

[@Zynh0722]

@@MakersMuse This is primarily just a thought, but I imagine if each pin was offset slightly beginning the motion, you could likely achieve an almost revolving opening pattern, where each locking lug opened sequencially

[@akashsaini100]

bro time for u to start work on new project :D

[@JamieMoller]

its a cam

[@7own878]

"And this important because it's beautiful." I like your mindset

[@DSSlocksmiths]

The expanded pulley has exactly the same friction contact area with the belt as when at the minimum size. There are many, many small vaults and lock boxes that use a system like this, but only to drive 3 bolts (up, down and the locking side, though sometimes there's a 4th, but that's normally where the lock bolt blocks the rotation) with the plate driven by the outside handle. Nice project! I'm also impressed you can get Fusion to move things that smoothly in the animations with contacts on!

[@thzzzt]

Use for the expanding pulley: How about an omni-directional hat stretcher?

[@blerst7066]

Perfect for people with big heads, like me.

[@julethug_7361]

Thats a beyblade

[@gabandreialcantara4649]

@@julethug_7361 YES YES YES YES YES!

[@donaldvincent]

There is an expanding table design that uses this principle in woodworking/furniture building circles.

[@zid_just_zid]

It could be used as a fly wheel, the change in size will affect inertia, dunno where thats useful tho.

[@MakersMuse]

Actually that could be pretty neat! Like how swinging your legs out on an office chair slows or speeds up your rotation.

[@liamburgo23]

I think I've seen a similar use case in some clocks

[@MrFixel112]

@@MakersMuse How about variomatic?

[@Andreas-gh6is]

It's also how cats rotate in midair.

[@conhennekens]

I think that has been tried in perpetuum mobile ;-)

[@pjnoonan2211]

Thanks for mentioning the book 507 Mechanical Movements. It has proved quite useful to me.

[@toyota9557]

You asked for real world use of this contraption? It is being used in a coil holder in a factory that specialises in sheet metal products. They have the sheet metal delivered in big coils and then flatten it. The device that holds the coils in place has four of these (slightly more robust than you 3D printed version) paralel to each other on a central axis. The main benefit being that it can pas trough the smaller hole in the flanges of the coilholder and uses a rotating movement for engaging the grip. So unrolling the coil automatically engages de spreader and centralises it. Keep up the fun work.

[@netyrk]

Thanks!

[@MakersMuse]

Cheers!

[@jaypaans3471]

Two thoughts: 1) expanding pulleys (or whatever they are called) are used in a centrifugal force clutch mechanism, like in a scooter. 2) pulleys are often use with ropes and they do not need to be concentric/circular to work.

[@Cloudman572]

Agreed, my 1st thought was the old massive leather belts used on 19th century machines (looms and machine shops with 1 engine powering multiple machines). The design could be used as a speed control if a idler tension wheel is used to compensate for the diameter change.

[@AlexSwavely]

The 'expanding pulley' used in belt CVT transmissions use a different mechanism to move the sides of the pulley toward the centerline.

[@Tom-yc8jv]

That is not for a clutch system, period. It's made to adjust the ratio of a pulley system, so the speed of the drive chain can be speed up or slowed down. Pulleys use ropes, chains, belts, tracks, or anything that is flexible, so as long as the shape is rotating, it doesn't matter what the shape of the pulley is.

[@OtakuUnitedStudio]

@@Tom-yc8jv The so-called "clutch" (actually governor) on a motor scooter is belt-driven, so it could potentially work with that. However, I don't think most do.

[@allhumansarejusthuman.5776]

They actually are for flat belts! Their purpose is similar to the purpose of the CVT but not identical. Ive seen them in manuals for machine tools from the 1920's and older but never owned one myself. Specifically for shapers, otherwise known amd arm-strong's These tools are so rugged even from the 1920's they still are in use in modern shops who can afford the space for them or shops that need skiving done like you se in copper semiconductor heat sinks! But they are very rarely made today, because of low demand and high market saturation, it really is an under appreciated machine tool. I could not hide my excitement to see a piece of it resurrected for a modern use!

[@jimabraham7275]

Just finished this, Angus. It's both ingenious and magical! My little granddaughter is going to love it on Christmas day. Thank you so much for a truly great design. I'm now printing out your egg puzzle. That'll keep everyone quiet!

[@MakersMuse]

Thanks for letting me know ! That's wonderful :)

[@jimigreco7230]

6:08 the spinning ashtrays segment unlocked memories from my past that I forgot I had

[@orbismworldbuilding8428]

someone i knew had one of those, knew them a long time ago

[@davebashford3753]

This mechanism is used in a woodturning tool called a Longworth chuck. Unsurprisingly, the Longworth chuck suffers from some of the same issues mentioned here.

[@microcar14]

They were onto CVT transmission for longer than we thought.

[@JoesWorkbench]

Reminds me of a longworth chuck that bowl turners use on their wood lathes

[@MakersMuse]

Hey you're right it is very similar to the scroll in chucks...! Great observation didn't even think of that.

[@Inventorsquare]

And a chuck boring ring.

[@maxleadleybrown]

@@MakersMuse No a scroll chuck is different again; A longworth chuck uses plates, one with left hand spiral cutout and one right spiral cutout, back to back

[@christiansorensen9175]

Came here to say the same thing. Looks just like a longworth chuck. I wonder how much more "bite" you could get out of a longworth chuck by driving it on a gear... Tried to use one once for a non wood turning application and was surprised at how little holding torque it had. (Could have been because I made it... lol)

[@whyoh8756]

they're used in expanding dining tables!

[@Hello_there_obi]

The description and diagram is very clear so yeah, it is simple! And beautifully elegant.

[@frankrwalsh]

it has been used in a bicycle for an automatic transmission. Ref: Yankee bike

[@samuelglover7685]

Thanks for that. It does seem like a pretty good mechanism for some kind of continuously varying transmission.

[@Silentscob]

Yankee bike 😂 perfect

[@partsdave8943]

I started using PrusaSlicer with my Ender 3 about a year ago. I was/am so happy with the results. Much better than I had been getting with Cura.

[@stuartcooke2787]

I’ve seen this design used for an amazing expanding round table that had extra pieces to fill the gaps rise up from the middle at the same time as the table expanded

[@mateofoulkes499]

I've always been bugged by how the hands in oval shape clocks don't adapt their lenghts to the oval shape. This mechanism might solve it so I can finally rest in peace

[@eekee6034]

When I was little, square clocks were in fashion, particularly in cars. The hands moving in circles really bugged me! :) I think a static cam could be used to change the hand lengths whatever the shape of the face.

[@tyrel7185]

Back in the 1800’s this design was used to adjust vanes inside water turbines that ran flour and grist mills and early factories that were water driven by rivers. They needed to compensate their RPM and torque for the machines based on different water conditions before and after big rainfalls, different seasons ect.

[@j4nch]

I love seing such mechanism. Is it just me or wouldn't it be very satisfying to see this driven by a motor like a safe :P. You well deserved a new patreon support for your hard work!

[@frankscruggs9089]

3 Jaw self centering metal lathe chuck : the single slot's pitch is so gradual that it engages each jaw several times

[@magicalpencil]

same on my old wood lathe

[@wesleymays1931]

this is that but 6 jawed and coarser pitch

[@tyrel7185]

Scroll chuck.

[@Tom-yc8jv]

That adjustable pulley is for changing the ratio in a pulley system, to speed up or slow down the drive chain. It's still used to this day.

[@VuLamDang]

yeah the expending pulleys is the corner stone for modern CVT transmission

[@SineEyed]

Makers Muse: "... I suspect this design didn't see very much use..." also Makers Muse: "... it's kind of bad at what it was designed for..." 😂

[@Akuseiko]

The Fletcher capstan table almost certainly uses a variation on this design.

[@crossthreadaeroindustries8554]

Super great use of 3D printing - mind benders.

[@marcfruchtman9473]

Really amazing design work. Thank you also for showing "507 Mechanical Movements" wow, what a great find!

[@mrclown7469]

Now we'll see how smart Popeye really is... 😅

[@MakersMuse]

Hahaha oh man... he'd just throw it off the balcony but I really want to find out now.

[@jakeman3659]

I could see a dm for dnd giving the final version to their players and a couple sessions later giving them the key cool box for sure

[@MakersMuse]

Yeah that'd be really neat! With secrets hidden inside.

[@benjybooth2840]

I was thinking how to put this in a dnd campaign

[@phantomflash6873]

that simple expanding pully just gave me (in theory)a brileant idea for a comitative beyblade gimmick

[@shadowsoul720]

I was trying to think of the same thing! No joke :O Only I'm wayyy to new to 3d printing to accomplish that xD

[@ControlledWrinkles]

When I worked at TechShop, there were a couple of guys that were laser cutting Delrin to make and sell cams for sewing machines like yours. I congratulated them on finding a solution to a very unique need.

[@adrianscarlett]

I was thinking of this for an expanding wheel a while back. My plan reduced the effect of the individual sections creating flat spots by utilising a stack of these offset from each other. I also added a rubber pad that compressed more at the peak of each section. I was attempting to make a bicycle wheel that could reduce diameter for easier use on public transportation. It works reasonably well.

[@benloi9874]

It reminds me of watertight (or airtight) door locks, designed to secure doors against pressure differences, used in ships or passenger aircraft.

[@Noahs80series]

Or the one of the vault door designs from Fallout

[@EllAntares]

@@Noahs80series Only FO4 111 ones. Most from before where just roll and push doors.

[@TheWadetube]

It's a table that has been around for some time now. The whole table gets bigger and adds a rising centerpiece that settles in to fill in the gap. As for a pully the tee shaped outer ends need to overlap while small.

[@Bob_Dub]

*_"This Lock Box Mechanism is 150 Years Old"_* Wow, who knew 3d printers had been around for so long?! ;D

[@pig_master101]

Wwow

[@nicolasdejardin3412]

I think somewhere we could adapt this mechanism to make a cool magnetic switchable hook Thanks for this from France

[@donteatyellowbears7387]

the mechanism shown at 2:29 is widely used in the Efteling themepark in the Netherlands. Motorised disks with bumps and dips in specific patterns make the actuators move, which in their turn pull and push cables to make various animatronic figures move.

[@Celcius1]

I could potentially see it used in earlier braking systems, like early pre-cursors of drum brake systems

[@samiraperi467]

Or a centrifugal clutch.

[@mclaynebalzly1739]

This would make for a really good cvt pulley for a cvt transmission. You could do this on a bicycle to make an automatic transmission bicycle

[@billysbikes8671]

already been done but it cant of been that great as it never caught on!

[@mclaynebalzly1739]

@@billysbikes8671 that’s lame

[@MarMonkey2606]

This actually reminds me of an expanding clutch mechanism.

[@juliusstande2355]

In the „Schraubdeckelzange PROFI PLUS“ by manufacturer „wmf“ you can see a perfect example for the use of this principle in the real world. There it’s used to grab the Glass lid when you’re not strong enough to open it.

[@jameshamilton4406]

Well done Angus. Model printed out extremely well no problems. Will now have to expand horizons and learn how to use Fusion 360, Thanks again

[@MakersMuse]

Great to hear! Thanks

[@sxeshoe]

With the symbols it looks like it could be a prop for Stargate.

[@jivejunior8753]

Precisely what I was thinking!

[@kurtlindner]

OMG, Angus doesn't hate Ender 3s anymore, the ground feels like it's gotten cooler... ;)

[@DownhillAllTheWay]

I would expect the expanding pulley to work reasonably well with a V-belt.

[@daleanderson1727]

Wxcellent, thank you. I will be using a variation on this design to lock up smething on my boat so this is very much appreciated.

[@nomekop777]

Thanks to this video, I've actually bought this book and a 3d printer!

[@nickiebanchou]

title : "crazy clever" my expectation : "oh is there more than a cam?" content: "actually it's a cam" i feel baited....

[@Gaswafers]

The Virgin Machinist vs The Chad Cam Master

[@andyman8630]

it's an S cam

[@lampostsamurai2518]

Okay, but hear me out, what if a cam, but actually six cams at once?

[@funkystudent5403]

Who else randomly got this recommended to them, but are happy about it?

[@ronanlanam1127]

Yes

[@eivindthorsen3547]

I would say the most regular use of this (can we call it "an extrapment-device" ? ) is in some variations of recoil starters, like chainsaws =)

[@CandleMan5]

Nice mecanism and I love your box design

[@MahdiDesigns]

At my job we made a prototype of a robot to drive through large underground pipes. We used this mechanism attached to the front of the robot to expand sensors outwards so they could make contact with the pipes wall. We later scrapped the mechanism and went for something else because it didn't provide a high enough expansion ration to cover the range of pipes we were working in... It could also be used to lift and move cylinders by expanding within them creating a high friction force.

[@willb5150]

I need this for my pimp'd out Magic the Gathering deck!

[@mkhornetHD]

well, a CVT belt transmission seems like an obvious use case for this

[@crelos3549]

7:11 you can still open it with a magnet and without the key.

[@Henrix1998]

Yep, this doesn't have "that" kinda key

[@bradster2214]

simple fix, give it an actual key to pull back a bolt that locks the disc in place.

[@jamoin3829]

Thanks to you i came along 507movements amd used it many many times🙏

[@paulpickett4522]

Dude....What you made is beautiful...

[@ssseaweed3800]

he literally just made a fancier version of a cookie jar

[@everythingawesome7671]

Lol yas

[@FarBeyondStrange]

Correction: He made the best version of the cookie jar.

[@asgard_]

Damn, the algorithm has good taste for once!

[@andyman8630]

Al Gore Rhythm

[@321doucheface]

@3:43 couldn't this be useful for changing gears on a bike? you'd just have to figure out a way to avoid breaking the chain when you adjust the size of the gear.

[@billysbikes8671]

derailleur???!

[@DSSlocksmiths]

Not with a chain it wouldn't, but with a belt drive and two microcontroller adjusted pulleys, it would work. Belt slipping? Tweak one pulley a fraction larger to tighten it.

[@xXxserenityxXx]

This one video makes me want to switch from EE to ME. That is a thing of beauty. Good effort bud.

[@GregTank]

Very nice design, great work!

[@XanTheDragon]

"so you can definitely print this at home on your low end 3d printer" snobbishly laughs in mk3s with mmu2

[@frogz]

*laughs tediously in 3d printing pen and hours...days....weeks of patient hand work*

[@happyjohn354]

screw 3d prinking i want to machine this out of steel and aluminum...

[@craigkoch977]

I've seen this used by the Amish in designing a round table that expanded for guests.

[@nickTeeKaystrickland]

This is very similar to a clutch system, expanding outward to engage with something at speed as it expands.

[@andyman8630]

centrifugal clutch, also used in old centrifugal point distributors

[@thearcenist]

Nice work, the mag latch is a very clever design. Well done!

[@viodre6652]

I've seen mechanisms like this before and it's been on of my favorites

[@JinNOSify]

It was used for the Chamber of Secrets! Jk

[@GiulianoMazzina]

Oh geez, I thought that at first too. LOL. IMO he missed a fantastic opportunity to recreate that door too.

[@Mobile_Dom]

aaaaaaaaaaandim now $5 poorer... happily

[@tonyradle8747]

Im early today... Lol

[@stephenlayland2889]

Consider an example of six tee-arms one hundred-twenty degrees on the circumference. They would meet on angled, rather than butted, faces. Each face would be in the shape of a parallelogram. The more steeply angled the sides, the narrower the gap perpendicular to the plane of rotation.

[@rollbot]

this is probably the first design of the continuously variable transmission clutch like seen in ATV and Snowmobiles. mind blown

[@Usual_User]

This looks amazing!

[@jdmeesey]

There are expanding tables that use this mechanism, and they have leafs that move into place with the spinning motion to fill in the gaps. In this way you don’t get an adjustable pulley as much as one with two distinct sizes. The tables look super cool too!

[@tigertiger1699]

Mate you are a very clever engineer 👍

[@beowolf9480]

I have a puzzle from I think the 90s which uses a bit of a modified version of this mechanism to allow them to move independently of others, however, where it's a modified version of this puzzle is that each pin moves a plastic divider, allowing some to move at some times and sometimes not at all, creating for an interesting combination puzzle which can be solved pretty easily

[@kengoold7157]

this is great. awesome channel

[@hadiTHEgreat87]

It's interesting! Love it! It maybe fun to add it to my list to make things with a 3d printer

[@jimmyzhao9748]

It's gorgeous. Maybe a candy jar that a *Bond Villain* would use.

[@BrunoPonce]

Well done, yet again!

[@thexbigxgreen]

You're a refreshingly pleasant presenter

[@amadeuscardenas4623]

Man I'm loving your work

[@KingQuetzal]

Was so funny I started watching the then realized I have this book so I went and grabbed it. Love the content.

[@woodyTM]

Thumbnail loosely resembles what the doors in Metroid look like and I was very confused and excited.

[@marcdraco2189]

Wonderful work young man!

[@anthonyquaye3577]

For me this is a very useful solution for variable initial regulator.

[@thekeywizard3313]

Most in floor safes use a similar mechanism to withdraw 3 bolts allowing the safe head to be lifted out with a handle. The better ones allow you to remove the dial, and some have specific dials that are offset from others, so without the correct dial AND the combination, you can't open the safe. I can provide photos if you like. Added: Also, the entire Wheel is the Cam, the Pins are pulled and pushed by Channels in the Cam which drive the Bolts, your bolts have arcs attached in the early version, but they are still bolts. A Cam is any driving device set to pivot on a single point.

[@DoSomethingFun]

The first cam /roller thingy is used in round tables that expand to seat more people.

[@rompis.a]

How do they cover the gaps tho?

[@DoSomethingFun]

@@rompis.a kzbin.info/www/bejne/f4LJnJ98bceniqM kinda like this but instead of popping up all fancy ya had flip each ext.