How to Make a Magnetic Xylophone Marble Run

This instructable shows you how to make a magnetic xylophone marble run that plays when you drop a marble down it. This instructable was inspired by a video I saw of a xylophone marble run (You can click >>here<< to see it), but I was very sad to realize this was a CGI simulation, and I couldn't buy one myself. Then I realized that I could just make one, so here I am after two weeks and countless failed attempts, presenting to you... the magnetic xylophone marble run.

Materials:

• Xylophone keys - you can remove the holders with pliers and take the keys off
• Super glue
• Marble - make sure it isn't too heavy or too large (you can also use a ball bearing)
• Rubber bands
• Magnets - make sure these are strong enough!

Tools:

• Ruler
• 3D printer + filament
• Pliers (optional)

1. Measure the width of the holes on the xylophone key, as shown above (in my case 8.5mm).
2. Open up a new Tinkercad project, add a cylinder, set the width and length to slightly less than the width of the holes (I chose 8mm X 8mm), and set the height to about 20mm.
3. Add a cone on top of the cylinder, set the width and length to slightly more than the hole's width and length (I chose 9mm X 9mm), and set the height to the same (in my case 9mm).
4. Duplicate so there is one holder per hole (⌘C+⌘V)

1. Measure the length of the key (in my case 80mm)
2. Measure the length of the magnet (in my case 25mm)
3. Add a cylinder and set the width and length to be a few millimeters larger than the cone (in my case 12mm X 12mm), and the height to the length of the key (in my case 80mm)
4. Add another cylinder, but make it only 3mm tall, and slightly wider and longer than your magnet (in my case 30mm X 30mm)

1. Measure the distance between the holes on the key (in my case 43mm)
2. Add a cylinder, set the width and length to slightly larger than that of the holes on the key (in my case 8.5mm), and select 'hole'
3. Rotate the cylinder 90 degrees and place it 20mm above the plane, cutting into the tall cylinder
4. Duplicate the cylinder and space it out the distance between the holes on the key (in my case 43mm)

1. Export the file using the button on the top right
2. Chose the file type that your printer supports (.stl, .obj, etc.) and download it
3. Print!

1. Make sure you have all the pieces (key, magnet, super glue, large holder, 2 small holders)
2. Superglue the magnet to the flat cylinder on the end of the large holder
3. Slide the smaller holders in the holes of the key
4. Add rubber bands beneath the key to hold it in place
5. Superglue the 2 small holders into the holes in the bigger holder

*Repeat steps 1-5, changing measurements if necessary, until all the keys have holders*

Congratulations! You have successfully made your own xylophone marble run pieces! Enjoy! (Below is a video of some experiments I did with it)