I had one of these Adafruit Circuit Playground electronic component plushies laying around just waiting to be hacked. So, thinking along the lines of the Resistor Value Helper Tie, having a resistor value decoder laying around would be pretty handy. Also fun to use and get kids interested in electronics.
This is a simple task to create a set of stacked freely rotatable rings like a cryptex, affix the color coded bands, and mount them on the plushie.
Relax. meditate, do not fear divining the value of any unknown resistor, oooooooooooooooooooooooooooooohm...
Step 1: Just a Few Parts...
A piece of plastic pipe 1 1/2 inch diameter to cut into rings for the color bands. I just got a kitchen sink tailpiece stub to use since it was cheap and I didn't need a whole long pipe to do any plumbing. The 1 1/4 inch diameter pipe for bathroom plumbing may be too tight so don't get that.
There are many ways to cut plastic pipe. If you don't have a power saw, a hand saw will work. Even better if you have a tubing cutter for plastic pipe. If you are really desperate, a cotton string held tautly and sawed across the pipe will friction cut it.
Just be sure to clamp the pipe securely in a vise or something and block around it in a block of wood with a V channel cut in it so the round shape does not slip.
I think you can also attempt this project with metal or even cardboard tubing(paper towel/toilet paper rolls, electrical tape cores) if desired. I chose plastic since it would be more rigid and would not really wear out the fabric of the plushie.
Have a small file or some sandpaper to deburr the cut edges of the plastic. No need to use solvents or solvent vapor like in smoothing out a freshly minted 3D print.
You will need sticker address label paper to print out the graphic for the color bands. You can also use double-sided tape or a good glue to stick the printed graphic on regular paper to the plastic tube.
Click on the graphic color chart image until you get to the original size file download area and download the image.
Step 2: Slicing and Dicing...
Mark 1/2 inch increments, allow for the cut away waste of the blade between sections.
Carefully, cut the 4 separate rings. Note that the plastic shavings will stick to everything from the static charge generated from the sawing and don't do this in the kitchen with the pipe balanced off the end of a cushioned chair with the wastebasket below hoping to catch all of the fragments...just don't do it...
You made a mess so just continue with the sanding to deburr and smooth out the plastic rings. Try not to breathe any of the stuff in as it is probably not good for you.
Step 3: Oooo, Look at All the Colors...
Note that due to the space limitation, you will have to use as double duty the 2nd ring to figure out 5 band resistors where there is a third place value.
It is sized for the 1/2 inch rings using 1 1/2 outside diameter pipe. This is how we celebrated Pi day by calculating the circumference to size the length of the graphic.
Print out actual size and do a test fit around the plastic ring.
I tried to run the sticker paper through the color laser printer but the color toner didn't stick too well. I printed out a regular sheet and glue-sticked it on to the sticker paper.
Cut out the different columns of the graphic to place on each of the rings.
Peel off the liner backing paper to expose the adhesive.
Line up on the ring and go around smoothing the sticker as you apply it. One end may overlap at the finish due to printing variations. You can trim it off or just stick it down over the other end.
Burnish it all around to ensure all is adhered.
Step 4: Slip It On...
Gently push the ring past the "eye". The ring should be confined snugly in the indented area between the eyes.
Of course, line the rings up in order by referring to the original graphic.
Take it for a test spin...
See? It's Mho better.
Do the right thing and make one today.