This project was originally released on my website www.robives.com

Resistors use coloured bands to show their value. There are usually four bands, the first two code for the first two digits of the resistors value, the third is the multiplier, basically the number of zeroes on the end of the number. The final band shows the tolerance of the resistor, how accurate it is.

This color wheel helps you decode the bands on standard resistor so you can see what value they are .

## Step 1:

Print out the parts onto thin card (230 gram / 67 lb)

Cut out the holes then cut out the parts.

## Step 2:

Lift up the three tabs in the largest disk. Thread the other two disks into place as shown above.

## Step 3:

Fold the tabs flat. Dab a small amount of glue on each tab and glue the cover into place. Make sure the disks are free to turn.

## Step 4:

Flip the disk over and glue the guide on the back.

## Step 5:

To use the Resistor Code Calculator, dial in the colours and read off the number - simple!

So for example a yellow, purple, orange resistor, would have a value of 47k ohms. Paper engineering meets electronic engineering.

<p>I made this handy device the other day. I enlarged it by 10% so I could see it easier and used a 10-32 screw and nut for the center. A drop of superglue on the threads after getting the right amount of drag to allow turning keeps it from backing off. I added a small neo magnet to the back for easy hanging. This was a great idea and will be used a lot by me.</p><p>Thanks again for sharing it.</p><p>Bill</p>
<p>Thank you for a great design! I laminated my pieces before assembly, hoping it will hold up under the use of my students. </p>
<p>Brilliant! Thank you very much!</p>
<p>muy bueno</p>
<p>pretty slick, i used hot glue to keep it together, spins like a dream.</p><p>thanks!</p>
<p>A GREAT REVIVAL OF AN OLD IDEA THEY WERE COMMERCIALLY AVAILABLE MAYBE STILL ARE AND WERE GIVEN AWAY IN MAGS LIKE PRACTICAL WIRELESS AND R.C.M.&amp; E. WHITE ART BOARD WOULD MAKE A STIFFER CHART STILL NO DETRACTION FROM YOUR IDEA</p>
<p>I just upgrade this good idea with<br>a sotch tape for have more solidity.</p><p>(FR)</p>
<p>Very nice idea.</p><p>Complimenti Idea Fantastica!!!</p>
<p>In my eagerness to get started, I sort of stopped at step 1, hence my unconventional build. </p><p>Still handy all the same, thanks. :)</p>
<p>R&aacute;pido e f&aacute;cil de se fazer. Muito obrigado!</p>
<p>Thanks for the great Instructable, I find it to be quick and easy to use and very helpful.</p>
<p>Will it work with regular paper?</p>
<p>Very nice idea</p>
<p>Really nice to see a made up version. Thanks!</p>
<p>This is a great idea! This takes all the guesswork out of resistor selection. I can spot a few (100, 220, 1000, 2200, 10k, 22k...) by sight - but otherwise I can't remember the mnemonics for the colors well enough and always have to test on the multimeter to be sure. This will be a big help. </p>
oh that is too cool... thanks for the 'ible!
<p>easy to make and great to have.</p><p>thank you.</p>
<p>Clever idea, very useful.</p>
This brings on a &quot;Why didn't I think of that&quot; moment!