A papercraft resistor calculator from Adafruit

The Adafruit blog just posted a neat papercraft resistor calculator. If you haven’t yet learned the horribly offensive mnemonic for resistor color codes, now’s your chance to have a cheap and portable resistor value reference.

This papercraft resistor calculator is the latest in the family of Circuit Playground tools that include a fabulous electronic reference app we reviewed some months ago. Instead of an Android or iOS device, the papercraft resistor calculator runs on its own mechanical computer; a series of four printed disks and some paper fasteners.

If you’d like to print out your own resistor calculator, Adafruit put up the PDF on GitHub and posted the Illustrator file on Thingiverse for easy editing. It’s not the old-school cool of a slide rule, but we could easily see this resistor calculator being useful if you’re ever lucky enough to teach electronics to children. At least then you won’t have to share that offensive mnemonic.

Slide rule for musical scales

For all those engineers who dabble in music [Magnetovore] has your back. Musicians simply must know their scales and he came up with a papercraft slide rule for major and minor scales.

The system is very easy to use. He’s uploaded PDF files that let you print out the mask for the top layer and bar chart and directions for the bottom layer. The top layer is laid out like a piano keyboard, with windows for each key and a couple of windows to identify the major and minor scales being displayed. Just slide the mask until each key is a solid color. The color codes show the tonic, third, and dominant for each key so you know where to start. In the video after the break you can see how it works by playing all of the non-black keys in order. But wait, if you order now you’ll get the slide rule for Cello scales at the same low-cost; free!

This is a fun quick-reference, but you really should know your Circle of Fifths. Continue reading “Slide rule for musical scales”

Piano Box is a digital synthesizer made of paper

We love the look of this papercraft piano which [Catarina] built along with some friends at NYC Resistor, a hackerspace in the big apple. It starts off as a cubic black box with a white top. But just lift that top as [Catarina] does in the video after the break and three of the sides fall flat to reveal a pair of speakers and the single-octave keyboard.

The key’s don’t move when you press them. Instead, she decided to use the CapSense Arduino library to implement touch sensitive keys. Each key is made up of a plane of copper foil tape, with a strip of tape running back to the center of the box where it is interfaced with an Arduino Mega hidden there. The Tone library produces the waveforms which are played by the speakers, and a set of LEDs on the upright side of the box illuminate the keyboard diagram as you press each key. You can see that there are short white bars on that display which correspond to the black keys on the keyboard.

If you take a look at the code, you’ll see the libraries really make the code for the project simple.

Continue reading “Piano Box is a digital synthesizer made of paper”

Locking notebook enclosure

[Dombeef] made a locking enclosure for his sketchbook. The diamond seen in the center of the book is formed by the four sliding parts of the lock. Only with the proper movements will you get the cover open so you can plan your next hack.

He was inspired by this wooden version created by artist [Kagen Schaefer]. There were no tips about how the mechanism was made but a bit of deep thinking led [Dombeef] to discover the secret. Being the papercraft ninja that he is (he makes things like gyroscopes, strandbeests, and claws) this was created using cardstock as the parts. There is a wooden pin on the right that serves as the latch. Each of the four puzzle pieces moves around each other to free a slot from its hold on the notched latch.

There is a diagram showing the parts and their movements in the post linked above. [Dombeef] also mentioned an animated GIF that he promises to publish soon.

Papercraft strandbeest is a great rainy day project


Here in the Midwest it sometimes seems like Spring will never, well…spring. We get that “April showers bring May flowers”, but nearly all of the last month has been cold and rainy around these parts. While things are improving, we think it’s always good practice to have a few fun projects at the ready, just in case your plans with the kids get rained out.

We think that Hackaday reader [Dombeef’s] papercraft strandbeest is a perfect idea for a rainy afternoon. The supply list is pretty short, requiring little more than some scissors, pliers, paperclips, and glue in addition to the thick paper that makes up the body of the strandbeest. The paper is cut into pieces according to the PDF template he includes in his Instructable, secured to one another via small pieces of paperclip.

Once the legs are all constructed, a main axis is built from one of the remaining paperclips, and everything is joined together under the main portion of the strandbeest’s body.

As you can see in the video, the legs work quite well, though the strandbeest can probably benefit from a hand crank in the short term. [Dombeef] plans on adding a small motor to his creation, which should get the strandbeest moving about quite rapidly once completed.

If you are looking for more fun projects to do with the kids, look no further than this papercraft gyroscope or these squishy circuits.

Continue reading “Papercraft strandbeest is a great rainy day project”

Papercraft gyroscope

Although spring keeps trying to break through the winter doldrums you might be looking for just one more weekend activity before the outdoor season begins. Grab the kids and give this paper gyroscope a try.

It’s not an electronic sensor made of paper, but the modern equivalent of a spinning top. The frame remains stationary while the center assembly spins at high speed, keeping the whole thing balanced on one narrow point. [Dombeef] put together a printable template which you can use to make your own parts. He got a hold of the heavy paper that’s used to hold X-ray film, but you can just trace out multiple copies of the parts and make a beefy section by laminating them together with glue. Combine the inner and outer parts using a paper clip as the axis and you’re ready to go. Pull hard on a bit of floss wound around the axis to get the center frame spinning, then sit back and see how long it will remain standing.