A 12 leaf (double layer) Iris box design. This box is essentially the same design as my 8 leaf iris box 'Octo-box', but with 12 instead of 8 leaves. The overall dimensions of the box are the same as the Octo-box, but this opens to a larger aperture. The mechanism parts utilise ridged pins and holes that clip together. The box is 80mm overall in diameter and the container opening is about 62mm in diameter. The box is opened by pushing the handle sections in an anti-clockwise direction.

No supports are required for this object.

I have since designed many other iris boxes which you can find on my profile page including improved versions of this design: Dodeca-box V2 and Dodeca-Iris Box.

The hinges of the mechanism use ridged pins and holes that clip together. The ridges alternate with 0.1mm layer heights, for this reason the parts must be printed with 0.1mm layer heights at the hinge and pin sections. Using adjustable layer heights in your slicer will allow you to print the majority of the parts at a thicker layer height for speed.

The effectiveness however of these hinges may depend on your specific printer and print settings, they shouldn't be either too tight or too loose. You could use contour xy compensation (ideamaker is a free slicer which does this) or alter your flow rate to adjust the fit for the hinges. The tolerance on the hinges is 0.15mm.

'top door 1' is a plain iris leaf for the top of the box while 'top door 2' is an iris leaf with a curved extension for opening the box. I recommend you print at least two of 'top door 2' (maximum of 6 as in the printed examples and assembly diagram) and arrange them on opposite sides of the box to allow ease of opening.

Part testing

I would recommend printing one upper and lower door with the settings you expect to print the whole model to test them. The hinges on the points of the doors are slightly smaller than the others so don't mix them up when testing them. Some of the hinge sections are quite thin as I focused on compactness, but are suitably strong on my models, using good quality PLA. A good first layer is critical on the 'lower door' parts.

Printing and assembly

For one box you will need to print 6x 'lower door 1', 6x 'lower door 2', 12x 'top door' (including the handle parts), 6x 'link' and 1x 'container'.

You will probably need some pliers or similar to clip the hinges together.

Firstly begin by assembling the iris mechanism. Be very careful while assembling the iris, not to put leaves in the wrong positions, as they can be hard to separate afterwards without breaking. In particular 'lower door 1' and 'lower door 2' must be interspaced around the mechanism (see the light and dark green parts in the assembly diagram). It's ideal if the iris is assembled in the closed or partly open position, otherwise it can be very hard to close if assembled in the fully open position and the hinges are still stiff.

After assembling the iris, push the link pins into the container (this may require a large amount of force depending on tolerances). Finally clip the links to the lower iris doors.

Your Dodeca-Box should now be fully functional! Let me know if you have any questions or difficulties with the design.