Swiss Army Knife Style Key Holder
updated February 23rd 2018

All the info you need should be in this description. If you have any further questions please check the comments section.

People have been sending tips! This is great considering that creating these designs and testing/adjusting from feedback takes time and effort. If you like the Proteus Keyholder consider sending a tip through the Tip Designer button on my profile page: https://www.thingiverse.com/ProteanMan/about

This works like a swiss army knife with your keys folding into the holder. Each holder is designed to have an equal number of keys at each end. The center bolt keeps the keys from crossing onto each other. You can fit as many keys as you want on this, just have to get a long enough bolt.

NEW
Old fashioned key size. This is a requested edition and has been sized to fit a general purpose old fashioned key (see image). You will need spacers for this one - look in the files. This size is larger than the standard key size with a length of 112mm and a width of 33mm.

Choices

3mm Bolts
2mm Bolts
Large Key Ring
Small Key Ring
Materials Needed

PETG, HTPLA, or ABS are preferred. Anything stronger works too. PLA may be too weak for regular use.
3x bolts
3x nuts or knurls
(If you don't know what a knurl is then look at the pictures. You can buy them in packages online. Check image for knurl dimensions needed)
Bolt Sizes
Both 3mm and 2mm bolts can be found by measuring the thickness of the keys you want to put into the key holder + 6mm.
example: 6 keys with 3 at each end (pictures). 3 keys total width is 10mm + 6mm for keyholder body insets = 16mm bolt length.

Knurl Sizes
There is a picture with the suggested dimensions of the Knurls. 3mm and 2mm knurls have varying dimensions based on manufacturer. They won't work unless you have the proper dimensions to grip the holes. Knurls can be easily put in with a large set of plyers/clamp/hammer. They need to be pushed into place so that the edges cut and grip the hole. I use these for almost everything since they are easier and more reliable than standard nuts.

Key Spacers
There are two sizes of spacers. You can use a washer if you want, but plastic spacers may be better for the keys.
Standard Key Spacers come in 1mm and 1.5mm thickness
Old Fashioned Style Key Spacers come in 1mm and 2mm thickness. You can make your own easily through www.tinkercad.com if you don't have a CAD program.

Note: I personally don't use spacers since I like how the keys grip each other and stay together in my pocket. It's all personal preference.

Printing
Print with the inside face of each part on the print bed. This should work perfectly for any printer.
Try using high infill - 75% or above when printing.

Any ideas let me know. Enjoy!