I started designing this crossbow in Tinkercad a while back, and it came out pretty well. After I finished, the design just sat untouched. Recently, I have looked back at my old design, noticing it still had many issues, like the fact that you had to use hot glue to assemble it, the striker was very short, nothing held the marble in place, it wasn't very powerful, and so on. So, I started refining this design, and fixed a lot of problems and made this crossbow easier to use, easier to assemble, more powerful and more accurate.

I made this toy crossbow to be a toy, and also part of a game. You can just launch marbles around for fun, but you can also play a game with these, with as many players as you want. In the game, you have a crossbow, some marbles, and 5 targets (I used plastic army guys). Then, you take turns shooting at your opponent's targets. You launch a marble, they launch a marble, and so on. I usually draw boundaries of how close your crossbow can get to your opponent's targets. You are eliminated if all 5 of your targets fall, and the last person who still has standing targets wins!

In the rest of this instructable, I will tell you how to print, assemble, and use this crossbow.

Supplies

All you will need is a 3d printer, this article, a marble, and a rubber band!

Step 1: How to Print

Start by downloading the .stl files at the bottom of this step. If your printer has a large enough print bed, download the file marked "Full Crossbow." This file prints both parts at the same time. If your bed is too small to print both parts at the same time, then download the files "Crossbow Body" and "Crossbow Striker," and print them individually. Then, use a slicer to prepare the model or individual models for your 3d printer. I used Ultimaker Cura to slice this design for my printer. My print bed is small, so I had to print the parts separately, and rotate "Crossbow Body" in Cura to fit on my bed, as shown in the image above. The striker might also need to be rotated in Cura to fit your print bed, if it is as small as mine. If you have a bigger bed on your 3d printer, you shouldn't have to rotate anything. You do not need to print supports for any of the files, because I tried to design them so supports wouldn't be necessary. The rest of the settings in Cura do not really matter, as long as they work for your printer. Then, print it!

Step 2: How to Assemble

Once both parts are printed, assembly is easy. In the video, I used a 100mm long by 6mm wide rubber band, which is the perfect size for this crossbow. If your rubber band is a different size, don't worry, they stretch! Watch the video above to learn how to assemble this crossbow with a rubber band.

Step 3: How to Launch

Launching the crossbow should be pretty simple, because I added handles for your fingertips and grooves to keep the marble in place. Watch the video above to see how to take aim, launch a marble, and take down a target using this crossbow. Enjoy!