Rapid Prototyping On the Cheap: Often in the classroom there is no access to advanced tools or expensive fabrication equipment. There isn't even access to the basic stuff sometimes. And finally, you often have to purchase it all ahead of time, which can be annoying for courses where the students are supposed to design something. Here's my list for cheap and versatile building materials. These can be great for science, robotics, architecture, etc. Nothing revolutionary, but it can be nice to have a list.
- Foam board, paper products like cardstock, and corrugated plastic. With clever designs like T-beams and I-beams you can make these into formidable structures. If you can find a delivery dock willing to work with you, you can source all the cardboard you'd ever need. Or dig through a recycling bin.
- Scissors, utility knives, and other simple cutting tools.
- Hot glue. Don't forget to get a lot of glue sticks; they go fast.
- Tape of all sorts. Scotch tape, masking tape, and duct tape are great. If you want something a little fancier, 3M sells filament tape in various flavors (different layouts of filament, different widths). Filament tape is a concept similar to ripstop fabric.
- Popsicle sticks, and old favorite.
- Straws are cheap and great for forming lightweight structures. The strawbee is pretty clever if overpriced. If you have access to a computerized cutting tool, just churn out a bunch of them yourself from a sheet of plastic.
- Stiff wire. Don't forget the wirecutters.
Electricity and Magnetism: There are so many advanced and cheap experiments out there for E&M. Electrical components can be bought individually even from major distributors like Digikey or Mouser. It will almost always cost you less than buying some kind of kit. The selection from these major distributors can be overwhelming but with a little research (just look at what is in the kits) you should be able to master their very useful search tools and winnow the selection down to what you need.
- Telephone wire is solid core wire. There are multiple strands in the main cable, each with its own color coded sheath. They work great with a breadboard. Specialized breadboard jumper kits are the biggest ripoff ever.
- Copper enameled wire. It comes in a variety of gauges and is used for things like motor windings and speakers (making motors and speakers are very easy experiments to run in a classroom).
- Velostat is a pressure sensitive material you can use to make cheap bend sensors. You can source a sheet from Adafruit and a variety of other sources online, depending on how much you need.
- Magnets. Cheap good fun. I have found that Ebay is the best way to find cheap neodymium magnets. These ship from China so expect a slightly longer shipping time.
- Foil, foil tape. Reflects light and heat, conductive, flexible. Great stuff.
Fancy Equipment for the Masses: This is a list of the more sophisticated equipment you can get that has really reached consumer level pricing.
- Thanks to a spate of new designs funded by Kickstarter, thermoplastic and even resin 3D printing is starting to be available for as low as a few hundred dollars. The landscape on what is available here changes pretty quickly and there is a lot to consider, so you'll have to do your reading. Filament is available for as low as $30/kg in some colors.
- Low cost oscilloscopes, function generators, and logic analyzers. Products like the Xmega Xprotolab and the Salae Logic Analyzer offer a lot of features suitable for many applications at very low prices.
- Arduino is hugely popular and for good reason. It is a microcontroller on a board with friendly features that make it very easy to get started with. At the heart of the Arduino is a chip called the Atmel AVR (or in some cases, a more sophisticated ARM chip). The convenience and low cost of the Arduino boards mean that even experienced users often choose to buy the board rather than to make one themselves (with the know-how you can buy the AVR yourself for a few bucks, put some circuitry around it, and flash the Arduino bootloader onto it).
- The Wixel is a $20 board featuring a microcontroller, wireless radio, and USB. There are lots of ways to add simple wireless capabilities to your project but the Wixel is one of my favorites. It is one of the cheapest solutions AND it includes a fully programmable microcontroller, so you can either use it as your all-in-one microcontroller solution or slap it on an existing development board like the Arduino.