Laser Cut Pom Pom Pressure Sensors!

So you have loads of left over yarn from your wonderful projects, and you've just invested in some conductive yarn, and you want to make some squishy pompom pressure sensors?

Here is how...

You will need

• Laser Cutter (I used this one)
• Scissors (strong enough to cut through yarn)
• 1/8" MDF (approx. 10" square, depending on size of pom pom you want)
• Yarn (use any thickness, mix colors, use up those little bits!)
• Conductive Yarn (from Sparkfun)

And here is a video of a pompom pressure sensor activated bongo drum in action:

You can modify the file to the size you want. Use the Illustrator file or PDF to cut out your pom pom maker on the laser cutter. If you do not have a laser cutter you can print out the makers, and stick them to corrugated card, which does the same job.

The file has 3 sizes -small, medium, and large.

This can be a bit tricky and takes some patience. Tie the end of the yarn around the maker in a knot, and then start to wind around. You'll need to be able to fit the ball of yarn through the center of your maker, so if you have a massive ball of yarn, just wrap it into smaller balls first.

Before you make one rotation of the yarn, add your conductive yarn.

Add colors you like -when adding a new yarn, just tie it loosely in a knot and then keep wrapping. The conductive yarn must be continuous from the center, so don't cover it up with the non-conductive.

To spread out your conductive traces, on your last circuit wrap the conductive yarn around the whole thing.

This part requires some patience. Find the center of the pom pom maker and start to cut the yarn you have just wrapped, using the maker as a guide. Cut all around following the path of the maker.

Pull the 2 maker parts away from each other, leaving a gap in the middle. Don't pull too far apart or they whole thing will fall to bits!

Tie some conductive yarn in the center of the 2 maker parts. Wrap around several times, pull tight as you can, and secure. The conductive yarn you are adding in the center will be your "wire" so be sure that it has contact with the conductive yarn you wrapped earlier.

When you have secured puff the pom pom out and trim off any stray long bits of yarn.

https://vimeo.com/97918836

Connect your to a Makey Makey (as in the video) to use as a sensor. Or you can use an Arduino for capacitive touch or use a specific sensor! Let me now how it goes!