Spring Loaded 50mm Square Card Holder

thingiverse

A case for some 50mm square QR codes I made with my K40. The cards are wood veneer on cardstock so I was worried about throwing them in my backpack without a holder. It should be able to hold other square cards of the same size as well. It uses a snap fit joint so no screws or glue are required, but you will need 4 springs to go over the posts inside. I have used both 3/8"x 5/8" and 3/8"x3/4" compression springs. Both work, but I prefer the 3/8"x5/8". You will probably need to use some strategic force to assemble the lid. I start by pressing together the edge above the opening slot and the lid, then quickly pop in each corner using the heel of my palm. Take care in lining everything up before putting the lid on since it won't come off again. Double check that the thumb slot is in the correct direction! It won't fit a ton of cards but it will certainly prevent them from getting bent while being carried around!