This model modifies the Prusa MK2.5S printer toolhead to support EIBOS Artemis extruder. These files have been tested on a Prusa MK2.5S but are believed to be compatible with MK3 as well.
The Artemis extruder is a small planetary extruder sold in the aftermarket. The advantages over the stock Prusa extruder are weight and filament drive torque. The installed weight of the extruder including the two mounting parts is 216g vs 422g for the equivalent Prusa extruder installation.
The Artemis extruder uses a small pancake stepper motor which drives a 15:1 planetary gear. This results in greater togue on the drive gears compared to Prusa. The drive is silent even under load. See shop.eibos3d.com/ for more details.
Filament Loaded to ExtruderGears switch is included with this modification in order to be compatible with MMU2/3 multimedia server. In the absence of a MMU2/3 this switch can be ignored or wired to an external Filament Out switch. This switch is functionally equivalent to the Prusa IR tower introduced in the MK2.5S upgrade. See Prusa documentation for proper menu settings for your specific installation. In particular pay attention to Menu Settings for MMU, Filament Sensor and Filament Autoload.
Two Prusa printed parts are replaced with this modification (extruder-motor-plate.stl and extruder-body.stl). The remainder of the toolhead is unchanged. See i3 MK2.5 to 2.5S Upgrade Printable parts by Prusa Research | Download free STL model | Printables.com for more details. The mating Prusa parts are included in the files section of this model for convenience. If you are unsure of the version of parts installed in your printer, print and replace the remainder of the included parts.
Assembly:
Remove existing Hot End from X-Axis carriage taking care not to damage Heater, Thermistor, and Fan wiring. Save the hardware for reassembly. Do not remove the X-Axis Carriage,
Remove and set aside, these parts. They will not be reused:
adapter-printer
fs-lever
extruder-motor-plate
extruder-body
extruder-idler
fs-cover
Extruder Stepper Motor
Replace the Extruder Stepper wire with the one supplied by EIBOS ensuring the wires on the motherboard side correspond to the wires on the removed cable,
Fabricate Filament Loaded microswitch PCB from a solderable breadboard. If using breadboard other than the one in BOM below make sure the plated through holes are interconnected vertically and hole spacing is 2.54mm. Cut a 3x5 hole section from the breadboard. See picture on left.
Solder the D2F-01L microswitch to bottom row holes 1, 3, and 5 (left to right in the picture above). Holes 2 and 4 will not be connected on this row. Ensure the lever arm points to the left in this picture (reverse side),
Solder 3 pin DuPont right angle connector to the opposite side of the PCB in the top row,
Open the copper land between the top and middle rows using a X-Acto knife,
Bridge pins 3 & 4 on the middle row using a small solid wire and solder. This step and the one above, connect the microswitch common to the middle DuPont connector pin and isolate the left most pin (5Vdc). Failure to isolate this pin will cause damage to the processor board!,
Install the microswitch/pcb assembly onto the shelf on the extruder-body using two M2x8 SHCS Screws. Make sure the mounting screw heads do not touch any of the circuit traces on the PCB,
Install three M3 Heatset inserts into extruder-motor-plate. Note: no heatset is necessary in the aft left hole. The extruder tensioner prevents the 4th mounting screw from being installed,
Install the Dragon hotend without the E3D barrel top to the extruder-motor-plate using four M2.5x10 SHCS screws. Mounting in this manner supports one handed nozzle changes. Prusa used the barrel top to secure the hotend but this requires two tools to change the nozzle,
Install a 32mm PTFE tube into the extruder-motor-plate. Ensure that it is fully seated into the Dragon hotend. The other end of the tube must be chamfered such that it presents no ridge to the filament path from the extruder to the hotend. Ensure no residue from the chamfering remains in the PTFE tube that will block the nozzle,
Install Artemis extruder on the extruder-motor-plate using three M3x6 Screws. The PTFE tube must be inserted into the Artemis extruder as part of this action,
Install the extruder-motor-plate and the extruder-cover unto the extruder-body using two M3x36 SHCS screws, careful not to damage the lever on the D2F-01L microswitch,
Connect the stepper motor cable to the stepper motor.
Reinstall the heater and thermistor into the Dragon hotend,
Reinstall both fans along with any supporting parts,
Power up the printer,
Reprogram extruder steps using Octoprint terminal or suitable alternative:
M92 E1350
Run self test. If any errors are noted, follow Prusa's troubleshooting instructions.
Verify the extruder steps per mm are correct:
Load filament to nozzle,
Mark 150mm from the extruder entry point on the filament
Extrude 100mm filament,
Measure from extruder entry to mark on filament. It should measure 50mm.
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