Nichrome Wire also known as Nickel Chromium Wire is a type of resistive heating element used in just about any electric heating device such as an Extruder and Heated BEd. RepRap uses Nichrome 80 which is composed of 80% Nickel and 20% Chromium.
Insulated Nichrome wire is generally preferable to prevent a short circuit but uninsulated wire should work as long as extra measures are taken to insulate the wires from each other. Kapton Tape or alternatively Teflon Tape is utilized for extra insulation.
You can buy on online shops the Nichrome Wire, however it tends to be expensive and they sell just a few amount of it, meaning that if you make a mistake you will need to buy more again and wait more time for it to arrive at your home. The best solution is to found on local shops, typically on ones that sells parts for electric machines. the same shops usually also sells the insulation.
See here a picture of the Casainho extruder using nichrome wire and insulation, both bought on local shop.
In RepRap-English, a Vitamin is anything that you need to make a RepRap, which a RepRap cannot itself make. Printed circuit boards, or stepper motors are vitamins right now. Plastic stuff is not. We're good at making that stuff.
- Pelican Wire
Note: This is a link from the wiki to stuff that should be on the wiki. We need a template for this, because that stuff is everywhere.