4b+The+hot+end

We want a page to contains about this level of detail. This text is from [] We will rewrite and expand the section on our hotend - the ceramic core option.

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For those new to RepRap, the hot-end assemble essentially acts like a hot-glue gun. The extruder assemble feeds ABS or PLA filament into the hot-end, which is held at 180-240C, depending on your chosen filament type. At the further end is a nozzle with a hole with a standard diameter of 0.35mm (more or less depending on what’s available). Note that 1.75mm filament does //not// yield improved resolution over 3mm filament. Layer thickness and precision is dictated by nozzle diameter. A good hot-end with a 3mm extruder will print as quickly and accurately as a 1.75mm extruder. Anyway, three types of hot-ends are currently in use: ceramic core, power resistor, and cartridge heaters. I wanted to buy a power resistor type hot-end from [|Mendel-parts.com], but every model was sold out. In fact, every power resistor hotend I could find anywhere was out of stock. Disappointed, I bought a [|Makergear 0.35mm Hot-End Pack] (a nichrome wire kit). Rick at Makergear is a great guy. Very helpful, friendly service, and his hot-end kits are enormously popular in the community. Unfortunately, Rick’s site is a disaster! Get it together, man! J
 * Ceramic cores use a piece of thin nichrome wire, [|wrapped tightly around the hot-end] and covered in a layer of hardened ceramic paste. The nichrome wire heats up like coils in a oven. Assembly is time consuming and messy, but it’s reliable.
 * Power resistor hot-ends are simpler. Stick a 5 to 6 ohm power resistor into the hot-end and you’re done. However, operating a resistor at 240C longterm means it’s operating way out of spec. As long as the resistor isn’t physically disturbed, it should hold up for months or maybe years. But if disturbed, the abused resistor will shatter.
 * Cartridge heaters are used by Makerbot. This is the same type of heating element found in soldering irons and similar devices. Cartridges are more robust than power resistors, but still not bulletproof. Makergear and a few others in the DIY community have experimented with cartridges. Supposedly they haven’t been widely adopted due to poor availability for our 12V application. It’s easier to use a cheap power resistor.