One of the things you find quickly when making your own circuits is resistors can be a real pain to organise. Resistors come in many different values so it's essential to have a way to organise them to find the value you want quickly.
I hit upon the idea of using test tubes to store the resistors. They are cheap to buy and using a test tube holder, easy to store.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Parts and Tools
1. 60 X Plastic Test tubes with lids– eBay. The ones I used have a 16mm ID
2. Test tube holder – eBay
3. Piece of dowel – Hardware Store. I think it was 10mm but to be sure, just take one of the lids from the test tubes to the hardware store to work out the size
4. Resistors – buy them in assorted lots on eBay
1. Some type of saw to cut the dowel
2. Hot glue
Step 2: Cutting the Dowel
The lids that come with the test tubes are hollow on the top. To be able to indicate what the value of the resistors are on each of the test tubes, I decided to fill-in the tops with some dowel. That way I could write the value on the tops.
1. Place the end of the dowel into the lid and mark where the top of the lid is. Give yourself a few extra millimetres so you can sand down the wood to make it even later
2. I used a band saw to cut the dowel so I just set it up so I could just multiple pieces at the same length.
3. Cut enough to fill all of the test tubes
Step 3: Gluing and Sanding the Dowel
1. Add some hot glue inside the top of the lid and push in a piece of the dowel you have cut.
2. Keep on doing this until all of the lids have a piece of dowel stuck inside of them
3. To clean up the finish, sand each of the lids with the dowel so the wood is flush with the top of the lid
Step 4: Adding the Resistors
1. Assemble the test tube rack
2. The resistors come in lots of 20. Grab one of these and take note of the value which is stamped on the paper holding them together. If it isn’t, then just use a multi meter to find the value
3. Roll-up the lot of resistors and place them inside the test tube
4. Write on the lid what the value is
5. Place each test tube into the test tube holder making sure that you have the values from smallest to largest so you can find the value you are looking for easily.
That’s it! You will be able to store 50 different resistor values into the holder. If you have more, then just buy another lot of test tubes and a holder.