Introduction: How to Make a 12 Leaves Mechanical Irirs

Picture of How to Make a 12 Leaves Mechanical Irirs


1 - bicycle chain......yes a bicycle chain, you'll seee what's for.
1 - copper sheet
1 - 15mm MDF board (20 x 20 cm will do)
1 - 3mm MDF board (20 x 20 cm will do) ( not on the pics)
1 CD tube case
And also some tools such as:

Bicicle chain tool
4 mm drillbit
130 mm Holesaw
75 mm Holesaw
Table saw or router table, or router, or dremel.
A blowtorch
Soldering wire and paste
A visegrip (recommended)
A Vise

You will also need a template file wich you can download from here, is a dwg (Autocad) file, you have to print it on a 1:1 scale.

Step 1: Getting Some Pins

Picture of Getting Some Pins

Ok, so what the heck is the bicycle chain for? well, every iris leaf, has two pins, one of them is  a pivot pin, and the other is a travell pin, wich runs in a slot.
So, in this project we will use the bicycle chain pins, ;)

Now,what you need to do is to take your bicycle chain, and dissasembly it several times, in order to get 24 pins, as the images show.

I put my chain tool in the vise to have a better handling.

Every chain link is componed by two pins, two little rings, and two little flat pieces, we will only use the pins, but save the other little pieces, cause they can be very usefull, and you never know when you gonna need them.

Once you get the 24 pins, clean them up very well (i use alcohol), to get all the oil and grease out, and we are ready for the next step

Step 2: Cutting the Leaves

Picture of Cutting the Leaves

Now let's make some leaves!

Ok, first print the leaf template, and glue it to the copper sheet.
Now cut the leaves!

Regular scissor will do the job (Remember, this copper sheet is 0,1 mm thick)

Once you get them all cut, remove the paper, and we are ready for the next step!

Step 3: Soldering the Pins

Picture of Soldering the Pins

Ok, now comes the fun part, we will solder two pins in every leaf, you must be carefull of where you place the pin, you have to guide yourself using the leaf template

I had no time to make a jig to precicely position the pin in every leaf, so i did it "by eye", anyway, we dont need surgical precision for this one.

Now, in case you're wondering ¿how do i solder those little things? i'll show you how i do it.

-First, i fix my visegrip on the vise
-Then i fix the leaf with the pin in position, in the visegrip
-Then you have to apply some soldering paste (flux), be generous.
-Heat it with the torch, just enough to get the paste melted
-Then, cut a piece of soldering wire, about 15 mm long, and twist it in a "U" like shape
-Then, wrap the wire around the pin base.
-And finally, heat everything untill the solder gets melted, use a soft flame, there's no need for exesive heat.
Do all that, and 20 minutes later you will have your 12 copper leaves set, ready to go!

Step 4: Making the Rings

Picture of Making the Rings

Now lets make the two rings.

First, print the rings template, and glue them in to the mdf boards.

-The ring with the runners, is for the 15 mm MDF borad, and the ring with the 12 holes, is for the 3 mm MDF.

-Then cut them with the holesaw

-Sand all the edges

-Drill the holes ( 4 mm holes)

-Cut the runners in the table saw (or router table, or with a dremmel, etc) i set the cut depth to 10 mm.

And that's all, now lets go to the assembly part!

Step 5: Assembly It!

Picture of Assembly It!
Ok! so now we have our 12 copper leaves set, and two mdf rings, let´s put them all together.

First, take the cd tube case.
Then put the 15 mm MDF ring on it
Then put the first leaf, with the tracking pin in a slot (the tracking pin is the one tha's a little offset, the other one is the pivot pin)
Then put the second leaf under the first one
Put the 3rd leaf under the 2nd......and so, untill you get the 12 leaves set up.

the put the 3 mm mdf ring on top, make all the pins fit with their respective hole (you can use some stick, or screwdriver to help) and YOU ARE READY TO GO!

Lets see a video of the iris in action! i must said this one works like a charm, opens and close very smooth.


PabloF8 (author)2017-08-09

Im checking your dwg files. The exterior circle is supposed to be 130mm, but I see 123mm. The inner circle is correct with 75mm.

Any idea about this?

JoshuaH159 (author)2016-12-05

is it possible to use pieces of heavy wire instead of bike chain pins?

Wynton made it! (author)2016-09-23

Hi Kommodore,

Thanks for these complete details and instructions. My client sent me your link and requested that I make a similar box for him, when I manufactured his engagement ring. It turned out absolutely perfectly and his girlfriend (now fiance'), was thrilled.

kommodore (author)Wynton2016-10-13

wow, sorry for the late response, that's one really cool ring box! pretty cool!


MauricioP49 (author)Wynton2016-09-27

Hey, I was wondering how long it took you to make it and how difficult you found it. I was planning on making one that can be ran with a motor. Thanks!

dhazelwood (author)2016-10-07

How do I scale this up for a 2ft windows?

MauricioP49 (author)2016-09-27

Hi kommodore, I was wondering how long it took you to make it and how difficult you found it. I was planning on making one that can be ran with a motor. Thanks!

manuelmasc (author)MauricioP492016-10-06

Hi MauricioP49. It may seems difficult, but you will notice by yourself that is not! I really enjoyed building it and it took me just 2 hour and a half (you could build that in less time if you don't spend a lot of time like me checking and rechecking everything in order to make it as perfect as possible ahaha).

manuelmasc made it! (author)2016-10-06

Hi kommodore! thanks for the great instructable!

I really enjoyed building it!! I didn't liked the plastic cd container so I modified a little the design in order to get a single piece.

kiel814 (author)2016-06-03

Is there a trick to make the iris reach a fully closed position. I have been looking at several different designs and most of them seem to leave a tiny opening when closed. This one does not seem to have that issue. Any explanation?

kommodore (author)kiel8142016-06-10

Hi, it will depend on the thickness of the leaves, when closing the iris, the leaves overlap with each other. In this case, the thickness of each leaf is 0,1 mm. When fully closed, the 12 leaves sum 1,2mm thick in the center. This causes the leaves to bend inward a little bit. So the thicker the blades, more force will be needed to bend the leaves in order to overlap with each other, sometimes making it impossible to fully close after some point.


LaylaY1 (author)2016-04-14

This is great! Have a few questions, how can you be reached ?

Malkaris (author)2016-02-22

Do the leaves reinforce each other? Would it be like bending 12 layers of the copper or does it feel rather flimsy when shut?

I'm playing with scaling your design up to about ~8-10"

It looks like the leaves are should cover 180 arc but how do you determine the width/thickness of the leaves?

lnino (author)2015-07-16

Thanks for this great tutorial. I love building things out of wood.

I am building the iris right now and let you know when I finished it.
A step by step documentation will be done as well on my Website:
I created a PDF file which has both files included (leaves and rings), with the same measurement.

I decided to make it a little bid smaller, because I can cut it with scrollsaw or bandsaw.
Maybe this PDF is usefull for somebody else. For me it was great because I have no AutoCAD and no knowledge about it.

Outer Diameter of my rings is 11,7 cm and Inner Diameter 7,1 cm.

greetings LNINO

kalexa1 (author)2015-05-14

Wow. Excellent stuff.

Marsh (author)2011-08-21

This is very well done! Excellent detail! I'm going to try to make it from tempered hardboard and large enough to walk through.
The only change I would like to see is that you post the iris.dwg file (presumably that contains the templates you mentioned) in a compatible file format. Very few of us are likely to have autocad.

kommodore (author)Marsh2011-08-22

You can also download this free dwg viewer from Autodesk.

ManOfScience (author)kommodore2011-09-11

Viewer does not allow modification; Not even scaling, as far as I can tell.

But I'm sure a quick search would provide someone else's example in a friendlier format that you could start from for your larger, wooden version. There are lots of iris examples out there.

I'm sure you won't need to start from scratch, Marsh; When i eventually get around to making my own variation I'll be looking for YOUR work as my starting point, so don't forget to use an open format and post!

Great work though, Kommodore! Elegant & inspirational.

kommodore (author)ManOfScience2011-09-16

try to scale it whe you print it, maybe there's an option there.

ryanto12 (author)kommodore2015-04-17

There is also the free draftsight program from solidworks/dassault systems. Its a pretty good clone of autoCAD, lets you modify and everything.

jeowf (author)Marsh2011-08-22

It might not be able to work because i think that jwkoi's one didn't close simply because wood doesn't bend. I think that the reason that this one closes to such a small aperture is because the copper can bend. You may have a problem with tempered hardboard.

pcooper2 (author)jeowf2011-08-24

It's not the flexibility of the iris leaves that matters — it's their thickness. Ideally, the leaves should be infinitesimally thin.

Marsh (author)pcooper22011-08-24

I think 1/8" will be thin enough for a three foot radius. I'll certainly post it if it's successful.

Marsh (author)jeowf2011-08-22

Tempered hardboard has plenty of flex, and I'm pretty sure it will have to be sanded so the edges taper thinner. I'll post is an an Ible if successful.

kommodore (author)Marsh2011-08-22

go ahead, and if it's going to be big enough to walk through there's no problem using the harboard, as long as it's no more than, let's say, 5 mm thickness, i think 3 mm would work great for the leaves.

about the dwg file, i could export it to pdf or something, but i can't assure it will maintain the original measures when you print it (it might be a problem just if you're going to use the 130 mm and 75 mm holesaws, but if you're going to use another tool to cut the rings, the original measures doesnt matter) so i'll try to export it to a pdf file.

garethllewelyn (author)Marsh2011-08-22

For Mac users there is a free app from the Apple app store to open.dwg files ;)

sketchpunk (author)2015-04-15

Love you're design. I tried making a 3D printed version of it. You're works better though.

LordNikon1 (author)2015-01-06

Just out of curiosity, is there a specific measurement used for the leaves so that they will close completely? I'd like to scale this a few different ways but I want to make sure that any adjustments I make will still create a closed iris.

RKumar1133 (author)2014-05-22


Great instruction set; thanks! However the pdf only has the template for the leaves. Is there another file that has the template for the two circles that need to be cut from wood?

purgedsoul (author)2012-04-19

Thank you for the template. It's wonderful! I made a scaled one out of chipboard, 220 GSM vellum board; and round tootpicks as pins. It was fun building it. I am now planning on making another one out of straighten pvc pipes and aluminum soda can.

kommodore (author)purgedsoul2012-04-22

Wow! Very nice done! show us some video of it, it looks awesome, im glad the templates help you!


purgedsoul (author)kommodore2012-05-06
Hi kommodore, sorry for the late reply, was busy with work, and tweaking the iris. Here's a video of it. Modified the iris, and put it in a pringles can.

kommodore (author)purgedsoul2014-04-07

Very nice!

OpIvy (author)purgedsoul2012-10-09

Love this and think it is amazing. I made one myself out of cardboard.
A small adjustment that I think could make the Iris even better is making the pins smaller, not as high as they currently are. They would instead look something like in this picture I included.

mathieulj (author)2014-04-07

Nice. Thanks for showing that us poorly equipped folk can still make neat things :) . Man I'd love a laser cutter but its really impressive what we can do without one.

kommodore (author)mathieulj2014-04-07


BroBotMKIII (author)2014-04-03


I tried to download the template and open it on my mac, but for whatever reason it didnt work, i downloaded a software called Inventor Fusion from autodesk, what software should I use to view it?

Is it possible for you to provide an image of the template like in step 2 that we can print out and use?

Thanks :)

kommodore (author)BroBotMKIII2014-04-03

I will upload a pdf file for the templates, just stay alert, i will upload it in a few hours, so stay alert!


BroBotMKIII (author)kommodore2014-04-04

Thank you so much :)

kommodore (author)BroBotMKIII2014-04-04

Ok now i upload it! i completely forgot about it yesterday XD, sorry, but now there's a PDF file with the leaves template, just print it as it is, i tested it first, and the scale is correct!


BroBotMKIII (author)kommodore2014-04-04

Hahaha ok great thanks :)

abdallah2319 (author)2013-08-06

Hello from Egypt, Kommodore.

Thank you for sharing this with the world.

I have a question, is there a ration between window diameter and the width or number of leaves? Thank you in advance.

gpresentey (author)2011-08-21

What's it for?

abdallah2319 (author)gpresentey2013-08-06

If you're ever seen the movie Lemonie Snikket's A Serious of Unfortunate Events it is a very cool window if you make one large enough.

the same design is used for camera shutters

Make a big enough one and you have a door :)

richardcole (author)gpresentey2011-08-22

what is that , i hv same question...

recklesskiba (author)gpresentey2011-08-21

who cares it is awesome. lol sorry i don't mean to be mean.

tisaconundrum (author)2013-06-28

Here's a thought.
1) place paper jpg copy on top of paper
2) place pin on top of paper that is on top of copper
3) vice grip it together
4) use blow torch and burn the paper away
5) solder as usual :D
6) profit :D :D

leoblue2002 (author)2012-08-29

thank you i dident notis it sry for spelling

leoblue2002 (author)2012-08-19

how do i download the template for the leafs?

kommodore (author)leoblue20022012-08-19

Hi, the template is in the "Intro" step, right before the step 1, is a DWG file, so you need Autocad or a DWG viewer to be able to see it.

If you want to scale it, you will need Autocad.


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