Sliding Fidget Toy

For my 3D modeling class, we were tasked with yet again another challenge. We were to design a fidget toy using the skills we had learned in class. We have discussed gears, hinges, sliders, spherical joints, and more. This design had to be 3D printable, functional, and involves some kind of moveable part. The fidget toy also had to be creative and not just something we copied from a tutorial.

I decided on making a box with a sliding lid that goes in two directions, similar to a dovetail box. It was very simple to design and is very fun to play with. Here is how I made it!

For the design of my fidget, I had to consider clearance, size, and functionality.

I knew I wanted the lid to slide in two directions without falling out if you turn the box upside down. For this, I created an angled opening where the lid slides in and out of. As shown in the picture above, I planned for this edge to be a trapezoid that the lid just slides into.

The next challenge was the lid itself. Since it is moving in two directions, all of the sides of the lid had to be angled. Therefore, the lid was similar to the frustum of a square-base pyramid.

The final constraint was the size. I wanted to make it small enough to fit into your hand when you use it. I also wanted to to be useable with only one hand. I had to make the whole design itself small to meet this criteria.

After sketching my fidget toy, the next step was to model it in Fusion 360.

I tried to stay as close to my sketch as possible, but I did have to change some dimensions. For example, the "height" of the lid space was a little larger than marked.

Something else I had to account for was the clearance of the lid. For the 3D printers at my school, the best clearance for a tight-squeezing fit is 0.3 mm. I made the clearance slightly larger, 0.35 mm, to make for an easier sliding experience.

In order to create this clearance, I offset the entire body of the lid. Since I made the lid and box separate components, this was very easy to do.

A difficult part, however, was actually creating the lid itself. I needed this to be a completely symmetric piece that would fit on both sides of the sliding space. I had to create multiple parameters in order to make the lid as symmetrical as possible.

One change I made from the design is the lid sliding space on the main box body. Instead of having a trapezoid that has angled corners, I chamfered those edges inward. I did this originally because my lid was too large for one side of the sliding area. It ended up working out when I 3D printed the fidget.

Overall, this piece printed very easily. It only took about an hour to print and was two separate pieces that I put together after it was finished.

The issue I had with the print was the lid not fitting into the sliding space I had created. Since I only made my clearance 0.05 mm bigger than a tighter fit AND the trapezoidal edges slightly melted outward, it did not even slide in to the box. In order to accommodate for this, I just sanded down the edges of the lid.

Now, with the revisions to the printed piece, the lid fits pretty well and it is functional.

Overall, I am pretty proud of this project.

Is this fidget toy the pinnacle of innovation and creativity? No. But, was it fun to make and fidget with? Yes!

If I were to change the design, I would make the lid have a larger clearance on the lateral sides that are angled. I think this would make it easier to fidget with and easier to fit the two pieces together.

Special thanks to Sarah (@ 3D Printing is Cool) for testing its "fidgetability".

Here is the STL link if anybody wants to print it: https://a360.co/3xCTQeQ

Happy printing!