Rugged Key Card Holder

Details

This is a plastic key card holder I designed since I have a bad habit of breaking them.  My card’s dimensions are 85.65mm long, 54mm wide, and .85mm thick and the modeled case is 106.65mm long, 68mm wide, and 7mm thick.  I printed my name on my holder, but I’m supplying two separate generic sets of STL files with different tolerances that apply to the card only, not the hardware.  I used .2mm tolerances, but the other option is .3mm.  I’m also supplying the Fusion 360 file in case you’d like to add your name or adjust dimensions.  I’m teaching myself how to use Fusion, so I apologize for any mistakes, but I tried to make it parametric.

If you share or remix it, please give me credit.

Print Instructions

I used Prusament PETG and printed the parts face down for the texture.  I used supports around the text and screw holes (because the screws are designed for 100 degree countersinks).  Make sure the support around the text is far enough away from the perimeters, or you’ll have a hard time.  If you want to test everything, I’m including test square files I printed to make sure I was good before printing the full version.

I used the Prusament PETG profile in PrusaSlicer

.10mm layer heights

15% infill

I added a color change in my G-code around 1mm

Hardware

This was designed with hardware from McMaster-Carr in mind.  The links are below. 

For the heat-set inserts, I used a drill bit, soldering iron, and a small block of aluminum with a flat face.  I made sure the holes were clear and allowed the insert to engage by using a small drill bit by hand.  I then used my soldering iron to heat up the insert.  It doesn’t take much, and I used the side of my soldering iron tip to start pushing the insert in.  Try to keep the insert straight and don’t push it in all the way with the soldering iron. 

I then immediately used the aluminum block’s flat face to finish pushing the insert in.  This made sure the insert was square and flush to the surface of the holder.  Be sure to let it cool before testing it. 

Black-Oxide 18-8 Stainless Steel Phillips Flat Head Screws

100 Degree Countersink Angle, 2-56 Thread, 3/16" Long

https://www.mcmaster.com/96640A294/

Heat-Set Inserts for Plastic

Brass, 2-56 Thread Size, 0.100" Installed Length

https://www.mcmaster.com/94459A230/