This is an upgraded version of my Octo-box iris box. This version now uses screws instead of 3D printed holes and pins, making printing and assembly much more straightforward. Using screws also allowed me to improve the mechanism, such that it produces a smooth octagonal aperture when fully opened. To open the box, you push the cutaway handles in an anti-clockwise direction. No supports are required for the parts.
I have made many of these boxes as unique gifts in many different variations and sizes as shown in the pictures.
This design was originally posted on MyMiniFactory in late 2017 and I have now moved it here as well. I have designed many other iris boxes which you can find on my design page: https://www.thingiverse.com/BrienAllison/designs.
I also have premium designs which you can find on my MyMiniFactory page: https://www.myminifactory.com/users/Brien%20Allison including an improved version of this design: Octo-Iris Box https://www.myminifactory.com/object/3d-print-93150.
The box (unscaled) is 80mm overall in diameter, has a 64mm wide container opening and is around 80mm tall. The part files are designed for M2x6 countersunk/flathead screws (as with my other designs which use screws); 40 screws are required in total for one box. The parts can be scaled to use larger or smaller screws e.g. the larger printed examples are at 150% scale and use M3x8 screws while the smaller examples are at 100% scale and use M2x6 screws. Note: it's a lot cheaper to buy the screws in bulk from a specialist supplier.
There are two versions of the iris parts. The basic versions are plain flat parts while the others are embossed decorated versions (used on the larger examples) and are designated with '(dec)' at the end. There is also a shortened version of the container 'Short Container' (used on the smaller examples), which reduces the height of the box from about 80mm to 40mm.
The 'Top handle' parts allow you to open the box by gripping a pair and turning anticlockwise. The 'Top door' and 'Top handle' parts can be assembled as you like on the top of the box although I recommend you position them in pairs (e.g. the smaller printed examples use 2, 4 and 8 handle parts).
I recommend at least 3 shell wall thickness with an 0.4mm nozzle, particularly on the container as this makes sure the walls are solid. I tend to use 0.2mm layer heights for the standard size boxes as this gives a good balance between strength, print quality and print time.
Step 1 Part Testing
Before printing off all the parts you should make sure the screw joints work correctly with your print settings. Print one 'top door' and one 'bottom door' parts. Check that your screws fit tightly in the holes in 'door top' but are free to rotate in the 'door base' holes and the head is flush with the bottom surface. You may need to use hole XY compensation (Ideamaker is a free slicer which does this) to get a good fit.
Step 2 Printing and Assembly
Printing and assembly
For the box you will need to print 8x 'Top' parts (any mix of 'Top' parts can be used but I recommend handles are positioned in pairs across the box), 8x 'Bottom door', 8x 'Link' and 1x 'Container'.
To assemble the box, begin by screwing the non pointed end of the links to the container.
Next take the door top (and top handle) and door bottom parts and begin assembling them into the iris mechanism. Match the outer holes on the top parts to the outer holes on the base parts. The middle holes and holes on the points of the doors should also be matched together, between the top and bottom doors, in a likewise fashion.
Continue assembling the doors, ideally in the closed position and keeping the screws straight to keep the box top as neat as possible. Be sure not to overtighten the screws, otherwise opening the box will be difficult. Once assembled, the iris mechanism should be free to open and close in your hands.
Next open the iris fully and place it upside down on a flat surface then take the container assembly and place it upside down on top of the iris door mechanism. Finally screw the other ends of the links to the final holes in the base of the iris.
The 'Octo-Box' should now be fully functional. Let me know if you have any questions or problems with the design