Way back when I very first started getting interested in electronics, and radio shack was more than a mini best buy, I picked up an invaluable learning aid / tool.

It was a simple piece of cardboard with 3 wheels inside of it, dial in the colors and it told you the values of resistors, capacitors, and on the backside 2 scales of inductors! (catalog number 271-1210)

While no replacement for proper education on the subject, it proved itself more than useful, so useful I still own the darn thing to this day 20 + years later, and even mention it in one of my Instructables as "the best darn piece of cardboard they don't make anymore".

The problem with it is, when radio shack changed from Archer brand stuff in brown packages to R (circle) stuff in blue and white packages, and eventually dwindled their electronic supply down to a couple of cabinets from 3 walls of the stuff, this handy device disappeared.

Without getting into too much RS / Tandy / Archer history, I would guess it had not been produced since the mid 1990's ... and thats a shame.

I have been meaning to make my own similar version of the card ever since I started Instructables, but ironically, I was going nuts trying to figure out a cardboard project for the "Gorilla Glue Cardboard Contest"...

Then one night, planning out how to shove a Cmoy amp into a 9volt battery, I was using this thing and all of a sudden all the DUH's came into place!

Welcome to my 6th Instructable.

Step 1: Tools and Materials

Computer (which if your viewing this I have to assume you have access to at least one)

Color printer, one that you can feed the paper from the back in a direct line to the print heads and out again (I used my wifes horrid 5+ year old HP all in one inkjet), even if you have a printer with a 2 stroke weed eater motor attached, curling the cardboard around the typical paper feed rollers will ruin it

Ruler / Straight edge

Sharp scissors

Xacto / Hobby / Scalpel / Matt knife with a fresh sharp blade

Black felt tip marker (sharpie is what I used)

Wire cutters

Thin cardboard, mine was cut out of a thick presentation folder / box, but the same thickness is often found in packs of plain underwear type T-Shirts

1 inch long "paper fasteners", thats the best name I can seem to find for them, they are a thumb tack sized doo-dad with 1 inch long thin metal strips on one side, put them in a hole and bend the strips over to hold paper. They are really common, I found mine at K-mart, in a pack o 100 for $1.29, but anyplace you can find basic office supplies should have them. Just for reference heres a link to some more fancy ones on staples.com


I used 1/8 eyelets for the axles and added our Makerspace's logo. I lasercut the holes and card outline. I will likely redesign it a bit to get 2 cards per sheet, then make a bunch to give away at our classes, etc. Thanks for sharing your work!
does RadioShack still sell the cards?
On a Commodore 64 simulator I made a program that asks if it's a 4 or 5 band resistor. You type in the color, then it matches it witch the right color (i.e. green then value would be 5) for the rest of the significant bands. Then it does the same thing for the multiplier band. (I.e. blue would be 10^6). And finally it asks for the tolerance value, and calculates the lowest to highest possible value.
BTW Its a split pin. LOL<br>
Very nice. Very handy. Just printed it out at work (they have the color printer) and going to assemble it tonight. I was teaching my son some basic electronics a couple weeks ago for a Boy Scout merit badge and had him looking up the color values from an index card taped up on the back of my electronics kit box. This will make it easier. <br> <br>I just hope I don't lose it... :-)
good one
it works graet<br><br>thanks bro
Your welcome!
THANK YOU! i have been killing myself having to figure out resistors! now thanks to this i can easily figure it out without having to search up a resistor color code chart on the internet.
your welcome, and the more you use one of these the less you need to
yes, especially when im away from the internet! 5*s
I was in dire need of using the like resistor calculator after our 9th grade teacher showed us those things a couple of years after teaching the politically incorrect version of the color bands memory aid that my father had used also. <br> <br>The prime reason I did use the calc thing from Radio Shack was because I was lazy and it was a bit quicker than figuring values in my head. ** grin ** <br> <br>Oddly enough, I still have that thing in workable shape sitting in my office. Probably because it got a break after one of the first programs I ever wrote for any home computer served the same purpose in letting me put the bands in and having it quote a calculated resistance for me on an old Commodore Vic-20. <br> <br>Did you resistance calculator look like the one in this uploaded image I'm including?
Yes thats it!<br><br>you can see mine in a picture on step two, and I still have mine today also
I must make this!
I realize no one has posted here in almost a year, but since I just now came across this, and have been tearing my hair out over resistors for ages, I figured I'd say thank you:). Just now finished mine, I used photo-paper instead of cardboard, so it's probably slightly less sturdy, and used rivets to fasten it. Now I'm off to make a second one, since the first was more of a hasty prototype, as I was unsure if the wheels would still move after being riveted (They do). Thanks again!
relatively simple project. going to make one as soon as possible!<br /> awesome idea!!<br />
i just finished mine now, it oozes amazingness, lol<br />
I am impressed!!!!<br /> <br /> Osgeld you are a genius!!!<br /> <br /> Very clever
this is very useful, thanks a lot<br />
Thanks, and your welcome<br />
I have many fond memories of the cardboard resistor wheels. I've found that a simple table is a lot easier and more straightforward however. I keep this chart above my bench and I can refer to it without even taking my hands off what I'm doing.
That is great, thanks. I&nbsp;have troubles with oranges and reds, and although they are clear on the chart, on a resister they sometimes are much less so. <div id="refHTML">&nbsp;</div>
agreed<br />
Very nice.&nbsp;&nbsp; At my workbench, I&nbsp;use a chart (as someone else mentioned) but when away from my bench, this would be a VERY&nbsp;valuable tool. <div id="refHTML">&nbsp;</div>
I used 1/4&quot; brass grommets instead of brads for a cleaner look.&nbsp; A lot stronger too.&nbsp; Grommet kits, made by either Stanley or General, are readily available at most hardware stores.<br />
I have a friend who is colorblind, and now I kind of want to make him a little scanner device that can read the colors off a resistor and tell him what the resistance is... Hmm... *pondering*
ohm meter?
nawh, that would be too simple...
Why would you bother making something to read the colors off a resistor only for it to change it back to its resistance, or build something to read the colors and then tell him the colors so he can re-decode them? And that would require a lot more electrical work and be less accurate than a ohm meter. Also, what if he is working with a SMD resistor, then the color reader thing woulding work... (well, neither would the card here, but the ohm meter would read both through hole parts and SMD parts, resistance wise atleast) Or better yet, get a a MULTI-meter
hey so am i instructables is red to me
Great little helper - exactly what I was looking for :)
Sharing this with us is really great. It comes in very handy. Thanks.
Thank you everybody for your kind comments!
ausome nice idea but what did you use to make the card
The card itself is made out of thin non corrugated cardboard, the graphics were done on Inkscape + The Gimp
Far out man, slick work. I can see some one making a super sized version for wall art in the shop. 5 stars.
theres some free software that has a resistor thing for coputers :)
That's pretty slick! good idea, thanks! I'll give you $5 to print out another piece of cardboard and send it to me. Just kidding! :)
This sounded like a good idea for college, so i made one in my college colors. i think it turned out really well. great idea!
looks good! (I was wondering when I would see others artwork on this)
How awesome would this be as a BUSINESS CARD!!
great instructable, but i prefer the ipod app just cause its an ipod app.....worth 5 stars though!!
<em>I love this.</em> I can never remember what those darn transistor colors mean; and even if I could, I would be constantly second-guessing myself.<br/><em>It's so simple, yet such a great idea!</em><br/>
My 1st PUC (Class - 11) teacher taught it as:<br/>&quot;B.B.Roy Of Great Britain had a Very Good Wife&quot;<br/><br/>Very Good Idea, But where to find a Colour Printer. I have two B/W Laser Printers!!!!!<br/><br/>5 Stars from me. <sup>-</sup><br/>
lol 660 so close
foo its been on the web for like 5 days and its featured already thats smart
The idea is very cool and helps in the long run.Glad that someone made this.
Could i scale it down to fit between two credit cards (old gift cards or something similar)? mdog

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More by osgeld:Project Advantage: Install a famiclone into a NES Advantage Joystick Spinner / Jog Wheel Inside of a VCR Head No CPU / MCU led pulse-fade 
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