Ruger Ten Twenty-Cue

There was a viral Instagram reel that showed up on my page a while ago. It depicted someone using a "rifle" as their pool cue: basically, when a trigger is pulled, a spring-loaded rod strikes the cue ball. It turns out there is somewhat of a market for this online (which I realize now isn't much of a surprise). I really wanted one of these contraptions to scare fellow students playing 8-ball in the commons block at UBC, but one of these things would set me back $361.00, which is essentially greater than my entire net worth as a first-year commuter. I'm so broke, I just did it myself.

For me, this project gave me a lot of practice with designing 3D printing parts that interfaced with each other and external materials. It was also a study into spring-loaded mechanisms.

This is a quick, easy project because I've already done all of the designing and testing. This is what I used:

Autodesk Fusion

3D Printer (All of the components were printed with 50% infill with PLA.)

11 Crazy Forts Rods (or any 9.5 OD, 450mm long rods will work. I think you can find aluminum rods of this OD on Amazon.)

The spring-loaded mechanism uses six 9x35mm springs from this box.

Rubber bands

Hot glue (or a similar, relatively strong adhesive)

I CADded all the components in Autodesk Fusion. I used the Sketch and Extrude tools as per usual, but I also used the Circular Pattern, Mirror, Loft, Fillet, and Thread tools to round out my design, distributing any stress applied to the model.

There are two types of connectors I used:

TYPE A CONNECTOR: This connector consists of a short rod with holes on either side. Two poles can be fitted into this part. With two of these connectors, I joined three rods together.

TYPE B CONNECTOR (SLIDER): This part has four tight holes on two sides, and a single loose hole through the entire part for one rod to slide through. I made the four-rod solid shaft of the gun with these connectors, and reconnected the central rod with the type A connectors between the loose holes.

Once I was done, I had a solid shaft with a single sliding rod in between it.

This is the largest component of the rifle and took me the longest to design. It consists of a handle attached to a hollow cylinder housing that is home to the springs of the rifle. To CAD this component, I took the slider connector model and worked with half of it as the part to interface with the rifle's barrel.

I attached four rods from the main shaft to the spring housing like with the slider connectors. I then slid the center rod into the loose hole in the center of the housing.

Now that the sliding rod had been inserted, it was time to load the springs into the firing mechanism. I took the six springs and three components: the Spring Rod Connector, the Spring Partition, and the Spring Screw. I slid the springs into each of the holes in the Partition, and attached one side to the Spring Rod Connector, which I then inserted into the spring housing. I connected the Spring Rod Connector to the sliding pole inside the spring housing. Finally, I attached the three exposed springs to the Spring Screw and screwed the entire thing into the chamber.

If done correctly, the sliding rod should rotate along with the spring screw. If not, the springs may fall out of position and the tolerances may be too tight.

Finally, it was time to bring everything to life. I printed out the final seven components: two pairs of pins and corresponding caps, the trigger, the lock, and the spacer (this was initially intended to be a reload mechanism, but was just changed to simply act as a large washer). The spacer goes into the spring housing. I had to unscrew the spring assembly and slide it in, then screw the springs back in again.

I fit the lock into the square hole in front of the handle of the spring housing (making sure that it was oriented in the correct direction, with the flat side of its slope facing towards the screw side of the spring housing), and slid the trigger in between the lock, where I then threaded the pin with knobs on the end through the holes in the lock and the slot in the trigger (I used a hot glue gun to attach the cap to the other side). I then inserted the second pin (with no knobs) through the set of holes in the spring housing and through the trigger's pivot, hot gluing the cap on as well. Everything was finally attached.

I finished by taking small rubber bands and wrapping them around the knobby ends of the lock pin, sliding them over the inset hooks on the spring housing. The trigger and lock were then pulled upwards into the spring housing, locking the sliding rod in place in loaded position when it was pulled back.

To use the rifle, just grab the center rod and pull it back until it locks in place. Then fire with the trigger.

Here is a clip of me using the rifle (I actually replaced the springs with a larger spring I found lying around in the shop, and I think I will try to find an even stronger spring to propel the cue ball with a bit more force).

This was such a fun project and is a great toy. I hope you enjoyed reading about my creation as much as I enjoyed building it!

Thank you for reading!