This component is the one that does the printing. You can print with one filament per hot end that's installed on your printer. Software can generally accept multiple hot ends but the limiting factor is the number of motors that your Arduino/Ramps 1.4 board can control seperately (the 2 Z-axis motors count as 1). Here are the main types of hot ends:
Hot Ends Filament Dia. Nozzle Diameter
- Single (e.g. J-Head or E3D) 1.75mm 0.25mm High precision low speed
- Double (e.g. Chimera) 3.00mm 0.30mm
- Tripple (e.g. Diamond Head) 0.35mm
- Quad (e.g. Kraken) 0.40mm Balanced
1.20mm Low precision high speed
We are using a "J-Head Mk V-BV" single hot end with a 0.50mm nozzle and 1.75mm filament. This gives great results and a great place to start as its more reliable as well. But you can easily change this by simply switching the hot end (or nozzle only if you prefer) and changing the settings in Slic3r and in Repetier-Host. (should be black not beige in picture below)
This is the device that takes the filament, heats it, and then places it exactly where needed to make your 3D print. It's main parts are:
The hot end ... melts the plastic
The extruder ... grabs filament from the spool and pushes to hot end
The mounting ... holds the extruder and hot end in place
There are all kinds of different looking extruders on the market but they usually fall into one of two types: Direct Extruders or Bowden Extruders.
Bowden extruders allow the extruder motor pushing the filament to be away from the hot end. It grabs the filament from the spool and pushes it through a PTFE tube to the hot end. This reduces the weight of the printing heat (package of hot end, extruder, and mounting) which can help increase print speed and reduce vibration, but its more prone to problems.
Direct extruders, like we use below, are more reliable or at least easier to trouble shoot and a little simpler. With a single hot end like we use, not much is gained with a Bowden.
Step 1. The 3 plastic parts
The photographs contain modified parts to make viewing easier, so they are not exactly as the 3 parts that we will use.
Add the left and right fans holders as shown below by screwing in the two small M3 x 25mm screws with M3 nuts. Tighten them sufficiently so the fan holders can remain in a chosen position. Once done, carefully place the 40mm 12v fans in each one.
The Hot end kit contains:
Brass nozzle (screws in heating block)
Brass heating block
Cooling tower (beige in the picture)
Heat resistor (heating element)
Thermistor (tiny thermometer)
PTFE linner (helps guide filament)
Heat Resistor opening in Heating Block
Thermistor opening in Heating Block
Heat Resistor goes here
Fitting in the parts is simply, but it is important to minimize the space or air between the heat resistor and the heating block. If its too lose, then wrap the heat resistor in foil before inserting in heating block.
The thermistor is very small an finky, but critical to your printer. Make sure the small wires aren't crossed (short circuit) as that will give a false reading that tempurature is very high. You should look to tape in in place using Kapton tape.
Parts for this section
1 Nema 17 stepper motors ... 1.8 degree per step and ideally 4800 g/cm holding torque
1 fan 30mm 12v
2 fans 40mm 12v
Mini hyena v2.0 for 5mm shaft ... little wheel with groove and teeth to grab filament
1 screws M3 x 25mm
4 screws M3 x 40mm
2 screws M3 x 30mm
3 nuts for M3 screws
Idler bar 5mm diameter
605zz ball bearing
J-Head MK V-BV kit: