Iris mechanism glasses out of paper and string.

The above video was made in Autodesk Inventor publisher, and the model was made in Autodesk Inventor.

The attached PDFs are for 11x17 printing, outline of pieces are included to cut out with dimension to scale.
If you have access to a laser cutter there is a dxf ver attached as well.

Time:
3-6 hours
Get your geek on.

Materials:
Ruler
xacto knife
paper glue (i used soba brand)
string - thats thin and strong ( i used book binding string)
Bristol paper- 100lb
hole punch -or something that punches 1/8 in holes or less
Mailing tube - 2 15/16" inner diameter (got mine at fedex)
heavy chipboard/cardstock (mine was 1/32 thick )

Step 1: Cut Your Pieces

Everything you need to cut is in the pdf EXCEPT the mailing tube rings--cut two 3/8" high rings out of the tube.
The 36 "leafs" are cut out of bristol paper, everything else (except mailing tube rings) are out of chipboard.
You don't really need a hole punch but having one goes much quicker, and the hole doesn't need to be exactly 1/8in hole, a smaller hole is fine.

Step 2: Leaf Bending

Take the bristol "leafs" and score along the line at the end. Be sure your leaves are facing counter clockwise.
Then bend forward to 90 deg and back flat to apply some glue, then bend foward again. Turn up your headphones and do this for all 36 leafs. Be sure to periodlically bend them to keep them all at 90 degrees as they dry

Step 3: Attaching Leaves

Next take your leafs and double tie a knot to the piece that has 18 holes in it. Be sure to loop the inner side of the ring and not the outter and make sure the folds you made in the previous step are facing up.

Snip off the excess string, get a close cut but not too close as to undo the tie, then push the knot in the hole do this for all 36 holes
*hint when tieing pull on one side of the string to drag the knot into the hole then snip*

Step 4:

Take your mailing tube rims and mark/measure 2.5" diameter from one edge to the next. Cut out a 1/16" high channel between your marking.

Step 5: Mechanism Assembly

Glue your flower ring piece to the bottom of the rim of your tube ring , with the channel you just cut facing up(left pic)
Let it dry and flip it over. Insert your leaf bundle with the bent pieces sticking up between the flower ring(middle pic). Test drive how the mechanism works. When inserting the leaf bundle be sure the tab is close to the right side wall of the channel you cut(right pic)

Step 6: Glass Frames

Take your glass frames and score lines where the legs of the glasses will bend

Step 7:

Now attach your mechanism to the glass frames.
Be sure you keep the tabs at the right corner of the channel you cut out of the mailing tube ring.

And your done!