Hi All!This is a blatant crosspost. ;-)TL;DR – I explain how a hotend and the fans work, and explain the terms people often get confused. For Beginners.I usually am not a fan of crossposts on Tech subjects, it’s confusing for everyone to keep track of the replies across multiple subreddits, but I thought this general enough to qualify.I don’t hang out much on 3DPrinting, mostly you’ll find me hiding on the CR-10 subreddit: http://ift.tt/2ElsAop we’ve had a rash of new users asking endless questions about fans, and clogs, and on & on, that all tell me that a lot of you don’t get the basics of how it all works.Let me see if I can help with the basic confusion, many who buy a 3D printer don’t get this part of it’s working (and it’s NOT obvious!!).THE ITEMS BOLDED ARE THE NAMES OF THE PIECES THAT YOU’LL SEE DISCUSSED IN THE 3D WORLD.The plastic must be melted to flow. (Duh)That’s the job of the HEATER which is inserted into the HEATER BLOCK, which the NOZZLE screws into.The temperature is monitored by a small glass bead with delicate wires called a THERMISTOR, inserted into a hole on the HEATER BLOCK the wires (not the bead itself) are held by a screw & washer.The HEATER heats the NOZZLE but it also heats a small threaded metal tube going upward called the HEAT BREAK. the lower part of the HEAT BREAK is hot and melts the plastic as it enters the NOZZLE.The HEAT BREAK has a narrow area just above the HEAT BLOCK that has no threads. That, technically, is the actual HEAT BREAK. BTW – The lower part is short, the upper part is long.The upper part of the HEAT BREAK is screwed into the COOLING FINS (some call it the COOLER BLOCK, but the proper name is HEAT SINK).This is the part cooled by the HOT END FAN. On most machines it’s the frontmost, some have it on the rear. Most run continuously, but some turn it on when a certain temp is reached.The purpose of all this is to keep the filament cool and rigid as it’s forced down into the heated chamber for melting. The narrow portion of the HEAT BREAK lets it stop the transfer of heat from the lower hot chamber to the upper cool chamber. (Narrow = less metal = less heat transfer).The fan, of course, is an integral part of this cooling, so must blow across the cooling fins.Lots of problems occur if the filament melts or softens before it reaches the lower chamber, mostly clogs …The entire assembly of the HEAT BREAK, COOLING BLOCK, HEATING BLOCK. HEATER, THERMISTOR, AND NOZZLE is called the HOTEND. (Yeah, I know technically the cooling block isn’t hot, but it’s still part of the HOTEND)The part that pushes the plastic into the HOTEND is called an EXTRUDER. Tip – keep the gear clean!(Yeah, yeah, I know. You would think that the part that squirts out the plastic is the EXTRUDER but it ain’t. THAT’S called the HOTEND. Don’t blame me, I didn’t name the damn thing.)On some machines it’s mounted just above the HOTEND (called Direct Drive) and some, like the CR-10 machines, it’s mounted elsewhere with a Teflon (called PTFE) tube guiding the plastic to the HOTEND.That setup is called a Bowden Drive and the tube is often (slang) referred to as the BOWDEN TUBE.There’s one more fan to cover (on the CR-10 series it’s on the right of the HOTEND). This fan blows down onto the area below the nozzle to cool the plastic once it’s been laid down, it’s called the PARTS FAN.Well there you go Kiddies. The basics. I’m sure I screwed something up and will be thoroughly beaten for a comma in the wrong place, but I gave it a shot. Hope this helps some of you beginners.EDIT: For a great video that shows you the pieces, see this one by /u/hobbyhoarderHotend explained and how to properly change the nozzle on a 3D printerPeace Out!PuterPro http://ift.tt/2EAHASR