This model is inspired by the wiha ergostar and was intended as my contribution to the Ergonomic Workshop Aids Contest:

An ergonomic way to have your hex keys / allen wrenches at hand.

Do you know the fiddling around until you finally can access the key with the right size? Wait no more, this is for you! With one turn of any key, all keys fan out so that the desired size can be easily reached. 

It accommodates keys from 6 down to 2 mm in 0.5 mm steps:

• 6mm, 5.5mm, 5mm, 4.5mm, 4mm, 3.5mm, 3mm, 2.5mm, 2mm

The design followed the KISS principles: Accordingly, there are plenty of spots where it could be reworked, most of them were (for now) deliberate design decisions and might be kick off points for remixes. I decided that:

• All the gears should be the same, just the tool accommodation should be different
  • The gears could be stripped of the unused teeth, reducing material and print time and obviously the overall size of the model → future revision
  • Gears of neighboring tool accommodations could also be on different planes, further reducing the spacing between the → hypothetical future revision
• The Housing consists of two identical half's, therefore the tool designations are on the gears
• Tool designations are only on the full numbers 
• Housing half's are glued (tape or superglue) together, they could be designed to clip together.

There are two types of relevant tolerances:

• tolerances between the printed parts are at least 0.2mm. It printed fine on a A1. I assume any modern printer will do. (See Post-Printing Instructions!) 
• tolerances between the actual key and the printed parts, these might vary according to your key. (This is not only the nominal size, but also the bending radius of the “L”-shape might come into play.) With your tools, your mileage may vary.

Printing: Print as already laid out in the .3mf file. It has the following features: 

• The gears are printed in place with the housing which will serve as support
• Print the second half of the housing separately. 
• The rack has two modifier features from the slicer that assure bed adhesion. Alternatively you can use a brim for the rack.  
• If you print separate gears, consider using an outer brim for bed adhesion.

Post-Printing: 

• Remove the bed-Adhesion features from the rack. 
• Since the lower part of the housing is also supporting the gears, you will need to break the gears lose. Press from the build-plate facing side against the gear and slightly bend the tool receiving end. 
• Assemble rack, gears in the orientation as printed (see pictures)
• Testfit the second part of the housing. Test if all Gears rotate as expected.
• Glue the two housing parts. 

Remixes are welcome. You can start from the Onshape files, or the provided STEP-Files.