Musical Skittles

One thing about being a grandparent is that you are always looking for new and exciting ways to entertain your wonderful grand kids; and in such a way that also allows you to tinker on your own hobbies.

Enter the musical skittle. Using an ATTiny13 (but any Arduino type board, that will fit inside the skittle, will work) and a copper piezo disc with a tilt switch, I created the following skittle that plays a short tune when it falls over.

Materials used:

• ATTiny13
• Copper Piezo Disc
• Push Button Switch (self locking)
• Tilt Switch
• 8 Pin DIP IC Socket Adapter (optional, just makes it easier to revise or change your code later)
• White 3D Filament
• Small, 1.7mm x 10mm screws
• Battery CR2025
• Battery holder

(Please note that these links are not part of any affiliate programme and as such clicking on them does not generate any revenue for myself)

Tools use:

• 3D Printer (Tevo Tornado)
• Soldering Iron
• Solder
• Small iron file
• Glue gun
• 1.4mm drill bit
• Small metal file or sand paper

Software:

• FreeCAD
• Ultimaker Cura

Using FreeCAD, I created the above skittle, exporting it to and STL file for printing.

To open the attached diagram in FreeCAD, download "Skittle-V8-doption.FCStd.txt", renaming it to "Skittle-V8-doption.FCStd" (Instructables does not allow one to upload FCStd files).

Open the "Base" and "Top" files in Cura, saving the sliced gCode to your printers storage card.

I printed with 20% infill, taking just under 9 hours in total.

I plan to print more skittles in various colours as well as mix some colours using the "Pause at Height" post processing script as discussed here.

Adapting Łukasz Podkalicki's code slightly I created the attached code.

In order to Successfully compile the code, I needed to install and use the DIY ATtiny code by James Sleeman.

I uploaded the code to the ATTiny using an Arduino, as discussed here.

I used EeasyEDA to design and print my PCB but this is not necessary and some strip-board could just as well be used.

Connect everything up as per the above schematic.

To connect the piezzo disc, sand a spot on the copper part (to allow the solder to stick); the inner white part does not need to be sanded or filed. Solder one lead to the copper part and the other to the white inner part.

Using a glue-gun:

• stick the switch in place.
• attached the PCB board to the "Base" upright.
• stick the Copper Piezo Disc to one of the internal surfaces.

Using a small drip bit, drill out the screw holes and then insert the screws to hold the "Top" and the "Base" together.

Switch the skittle on and your grandchild is now ready to bowl over the skittle(s) using an old golf ball.

Have fun :)

I had find making this and look forward to adding more interesting skittles to the collection i.e. different colours, colour combinations and patterns or embossings.

On a side note, better sound volumes can be attained by experimenting with how and where the piezzo disc is attached; but I will do that another time.

Lastly, I have just started playing with surface mounted devices so going forward I will probably try and shrink the electronics :)

Final Comment

I finally got my multi-colour print done but a number of times when I changed the filament I managed to accidentally move the head resulting the the print resuming at the wrong place. On eventual completion I thought that I got it right (after having to restart a number of times) only to discover that on the last change I must of pushed the heard to the left or right a little so the to part is off-center a little :( Next time I am going to add commands to the gcode so that the filament is loaded without me having to push it at all or as much.