# Celebrate National Pi Day with These 3D Printed Items

Some people get irrationally excited about dessert, and some people get excited about irrational numbers. When I first heard it was National Pie Day, I imagined my favorite flavors and a large bottle of whip cream to accompany them.  But that’s not the kind of pie we are talking about here.  Today, 3.14, is special for lovers of the number π (the Greek letter representation that has been used since the 18th century), or “pi.” The ratio of a circle’s circumference to its diameter, pi is commonly approximated as 3.14159 — as you may recall from your good old school days.  It cannot be expressed exactly as a common fraction because it is an “irrational” number, meaning that it never settles into a permanent repeating pattern. Its representation in decimal form never ends. These are just a few of the reasons that pi has such a devoted following. Here we offer a sampling of 3D printed items that are pi related to help you celebrate the wonders and joys of this irrational day. (It’s also Albert Einstein’s birthday by the way.)

1. Pi-Penholder

People favor household items to remind them of some of their favorite things, so why not 3D print your own Pi-Penholder? Thingiverse offers us this option with a sleek and simple design featuring the trailing number around the rim of the holder. It can also be used as a vase, or a place to keep coins. Like the number itself, its uses seem endless.

2. Pi penholder small

Over at Shapeways, there’s another penholder that features the numbers throughout the base instead of surrounding the rim.  This one is available for \$39.90 and can be printed in plastic in a variety of colors.

3. Mobius Strip 3.14 Pi Color

A Mobius strip is a surface with only one side and one boundary, so what better thing of wonder to pair up with pi?  Shapeways offers this 3D printed colorful item from Vidalcris that claims “you will never have so many digits of pi in your hand” in sandstone for \$29.99.

4. PI D6

mctrivia brings us a functional form of pi as a die that has been tested to work as it is “perectly weighted and all sides are roughly the same landing area.” Each side is numbered  on this .75 x .75  x . 75 inch size item that can be printed in metal or plastic with a smooth finish. Why use standard dice when you can have your own pi symbols instead?

5. Pi Signet

\$10.75 can get you a nylon plastic white version of this pi ring, while \$58.75 can get you the stainless steel version.  Either way, if you are a fan of the number pi, you can’t go wrong sporting this timeless piece of an endless number that is featured on the outer band.

6. Science jewelry: Pi Pendant

If jewelry and supporting science education sound like a good idea, but pendants are more your thing, somersault18:24 brings us this pi pendant that is available in a variety of metals between \$60.00 and \$200.000.  But remember that some of the proceeds will go to supporting science education. somersault18:24’s website has already raised \$3,121 for science education, so you can be part of this bigger project and wear a nicely designed pendant at the same time.

7. Pi Earrings

Staying with the jewelry theme, pi earrings are also available from CaseStudios. (Apparently one can go onto Shapeways and view pi jewelry in almost every shape and form imaginable!) These earrings can be printed in any number of metals, with the most costly in platinum for \$999.99 and the least costly in matte black steel for \$22.99.  So, top off your ring and pendant set with some earrings and you will be ready for any National Pi Day party that comes your way.