Proteus Key Holder

Swiss Army Knife Style Key Holder
updated Sepember 16th 2018 - 3 sizes, design tweeks, logo size tweeks for printing combatibility, removed older versions from download list, removed M2 sizing because it was barely used.
updated September 11th 2018 - All New "Hard Edged" version with larger logo that is easier to print. Fixes old issue with the details in the logo not printing on most printers.
updated August 31st 2018 - File names and knurl hole tweaks.
updated February 23rd 2018 - Design and finalization of pieces.

Help support my designs by going becoming a patron: www.patreon.com/proteanman

Basics

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 remove it if you want). Fit as many keys as you want, you will just need a long enough set of bolts.

3 Sizes to print
Regular - common key sizes, house, mailbox, car, etc.
Large - industrial, heavy duty locks, keys you can't buy in a hardware store
Extra Large - usually old fashioned style keys, but who knows what else you can fit on this? ... it's big

Bolts/Nuts

• 3mm (M3)
• 4-40 (Imperial UNC)
• 4-48 (Imperial UNF)

Knurls

• M3, 5mm outer diameter, 4mm height
  Search ebay.com/aliexpress.com/amazon.com for the proper sized knurls

Designed for 3mm (M3) bolts and nuts there is equivalent imperial (USA) sizes available. If you want the strongest and most reliable design you will need to use the Knurl option. These can be obtained from Ebay.com very easily. Search for M3 Knurls and ensure that they are 5mm outer diameter and 4mm in height. There are varying knurl sizes if you aren't careful. To put them in you can use a soldering iron to just melt them into the slots or use a heat gun to heat them on a bolt and then insert them. Check the video (coming soon) for a visual guide.

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 Lengths
Measuring the thickness of the keys you want to put into the key holder + 7mm will give you the length of bolt needed.
example: 4 keys with 2 at each end (pictures). 2 keys total width is 6mm + 7mm for keyholder body insets = 13mm to 14mm bolt length.

Knurl Sizes
There is a picture with the suggested dimensions of the Knurls. 3mm 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 or melted into the holes with a soldering iron. 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 permanent 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 - 50% or above when printing.

Any ideas let me know. Enjoy!