Tired of your bills getting lost or just ending up as a crumpled mess in your pocket? Or maybe you just want to keep your money more accessible than tucked away inside your wallet. Either way, a money clip does keep it all together. And of course if we can customize it to make it more special, all the better.

OK then, let's get started.

This Instructable is a part of the 3D Project Challenge: Money Clip. Create your own 3d file for a money clip or modify the template to enter.

Step 1: Design Issues

I came across a few designs for money clips, but many had the same problem: they didn't grip so well. Also, many were thicker than I wanted and would be too bulky in a pocket.

Tinkercad.com is great ant their tutorial for a money clip is great for learning, but the results weren't so hot once I printed them. Too big and bills easily fell out when I printed it on a MakerBot Replicator 2.

So that leads to two things to fix. The size (no problem) and the grip (a bigger problem).

Step 2: The Grip

With regular money clips made out of metal you can get a slight spring action by folding the metal over. Having the metal flush is no problem here. But that is a problem for 3D printing since you always need some gap. Otherwise the print would fuse together and be useless.

To solve this I created a dip in the body of the money clip. Then the arm of the clip could extend past the original surface of the body. With this done, the money would have a lot more friction since it would have to go around the arm. This also gives us some tension since the default position for the arm is past the body.

The result? Money stays in nice and tight. Even with one bill folded over it held strong, keeping the bill in place while it was being moved or shaken around.

Step 3: How to Make the Design

The creation of the file in tinkercad uses just a few basic shapes: cylinders, boxes, and a round roof. Here's how it was put together

Make a cylinder that's 12cm in diameter and 30 mm tall
Subtract a 8 mm from that for the hole
Subtract an offset 20 mm cylinder to make the result a "C" shape and make these 3 cylinders a group
Add two elongated boxes for arms
Add cylinders to the ends of each arm
Subtract a cylinder from the long arm and make the long arm a group
Add a round roof to the outside of the long arm

You can see the results on Tinkercad here. This result is a template that I encourage you to copy and modify. Do whatever you want with it.

Then export the results as an STL and you can print it. I used the basic low-quality settings on Makerware for the Replicator 2 and it came out fine.

Step 4: Tweak the Design

With the template in place and working, play with the design by adding or subtracting elements. In these files I subtracted triangles and circles to create some geometric patterns. The results were printed up by our friends at 3D Creation Systems and all are still champs at holding onto money.

If you want, you can tweak these files as well. Here are the links: