Drain Gun Storage Box

To help clear the drain line for my HVAC unit at the house, I purchased a CO2 gun off of Amazon. When it arrived, it came in a bubble mailer and I had no real way to store it. So, I broke out Fusion and modeled up a container and 3D printed it.

The CO2 Drain Gun is comprised of the five CO2 cartridges, the gun itself, and a hose attachment that you press against the drain line to create an air-tight seal. I didn’t just want to throw these into a random box, and I wanted to reduce any noise (and potential damage) from the metal CO2 cartridges banging together. I started by measuring all of the items and putting the notes in my notebook.

To avoid the cartridges from rolling around, I created a tray to nestle them into. But, I needed to also put this tray INTO something, so….

The storage box is based off a parametric Fusion model that I downloaded off the internet. This particular box was scaled to properly fit the CO2 gun components and internal printed trays. It was printed in Bambu Lab Light Gray PLA with Bambu Lab White PLA used for the latches and inner trays.

The latches are hinged using M3 x 20mm screws. The same screws are used for the clasps for the latches as well as the hinges on the rear of the box.

I modeled a second tray that exactly matched the first, but also included small posts so that the trays form the “bread” of the CO2 cartridge sandwich. The posts are designed to prevent the top and bottom trays from pivoting like a see-saw.

Adding in the cartridges shows how efficient the spacing is inside the box.

I reprinted the first tray (pictured here) because I realized that I needed to add a finger hole so I could pull the top tray out of the box…

…as seen here.

This is the finished look of the sandwich. To save on filament, the trays don’t fully envelope the CO2 cartridges. Instead, the bottom tray (with the posts) holds the top tray (with the finger hole) just above the cartridges. Hence, the “sandwich” analogy. Both trays were designed to snug up to the cartridges to prevent them from moving around.

Next up, the hose is coiled to not only fit it into a smaller footprint, but the rubbery material it’s made from, along with the hose’s desire to uncoil itself, snugly holds itself to the confines of the box.

The CO2 gun then rests on top of the hose. How do I keep these two components from rattling around? Glad you asked…

One half inch of foam was cut to fit the box cover and is press-fitted into place. I decided to not glue the foam in incase I needed to replace it in the future.

With the foam in place, when the lid closes, the foam presses down on the gun and hose and prevents them from moving.

And, to top it all off, I had to print a small plate so I know what’s in the box. The same white PLA was used with Bambu Lab Black PLA for the text. In hindsight, I probably should have printed the text flush with the tag instead of raised. But, I didn’t think of that until after I had attached it with CA glue.

Finally, here are the design notes. The CO2 Gun Storage Box is now living out its life in the garage with all the other tools.

Project ID: C001