⬢Torx TX10 key

⬢Torx TX6 key

⬢Torx TX8 key

⬢2.5 mm Allen key

⬢Universal wrench

⬢Nose pliers

⬢Side cutters recommended for cutting zip ties

⬢Prusa lubricant (1x) supplied with your printer

⬢PG-assembly-adapter (1x)

The following step is only necessary if you have a filament loaded in the current toolhead.

⬢Unload the filament from the hotend. On the screen, navigate to Filament -> Unload Filament and select the tool, you want to working on.

⬢Remove the filament from the hotend. It is not necessary to completely remove it from the printer. Just a few centimeters (inches) above the extruder.

⬢Cool down the printer to room temperature. On the screen, navigate to Preheat -> Cooldown.

⬢Turn the printer, so the back side of the printer is facing you.

⬢Loosen two screws on the cover slightly. No need to remove them completely. Push the cover to the right and gently remove it from the screws.

⬢Push the safety latch and disconnect the Nextruder cable from the connector "DWARF1".

⬢Attach the antenna-holder to the screws and push the cover to the left. Tighten the screws.

For older CoreXY back covers without hexagonal cutouts (honeycomb pattern), loosen the screw in the dock as instructed. The procedure remains the same.

⬢Using a 2.5mm Allen key, untighten the screw inside the (middle hole) dock.

⬢Keep the Nextruder cable bundle next to the printer.

⬢Turn the printer, so the front side is facing you.

⬢Snap off the x-carriage-cover back from the X-carriage. Do not throw the parts away!

⬢Using a T10 Torx key, remove two M3x12bT screws. Do not throw the parts away!

⬢Hold the Nextruder during disassembly.

⬢Untighten two M3x12bT screws using a T10 Torx key. Do not throw the parts away!

⬢Detach the Nextruder and place it nearby, we will rebuilt it in the next steps.

⬢From the front side of the Nextruder, using a T10 Torx screwdriver untighten two screws to release the cable support. Do not remove the screws completely!

⬢Press the blue fitting and pull out the PTFE tube.

⬢Press the secure pin and remove the Nextruder cable.

⬢From the right side of the Nextruder, using a T10 Torx screwdriver unscrew two M3x20rT screws. Do not throw them away!

⬢From the left side of the Nextruder, unscrew two screws using a 2.5 mm Allen key. Do not throw the parts away!

⬢Pull out the Nextruder body from the Nextruder. Do not throw the parts away!

⬢Loosen the screw, just a few turns are enough to release the dwarf-cover-door. No need to removing the screw completely.

⬢Open the dwarf-cover-door widely.

⬢Gently remove the zip-tie using a pliers. Watch out for the cables! 

⬢By pressing the security latch, remove the heatsink fan cable from the Dwarf board.

⬢Remove the heatsink fan. Do not throw the parts away!

⬢Push the idler-swivel upward.

⬢Pull the idler-lever downward in order to release tension on the gearbox.

⬢Fully loosen three M3x25 screws from the printed gearbox cover. Keep the screws in the assembly, don't remove them completely.

⬢Carefully slide the gearbox assembly off. It is necessary to remove the entire assembly in one piece. This means PG-cover (top plastic cover), PG-ring (brass ring), PG-assembly (metal gears), and main-plate (bottom plastic plate), all joined by M3x25 screws.

⬢With a Torx TX 8 key loosen the grub screw in the extruder. Do not remove the screw completely. A few turns are enough to release the hotend assembly in the heatsink.

⬢By pressing the security latch, remove the hotend thermistor cable from the Dwarf board.

⬢By pressing the security latch, remove the hotend heater cable from the Dwarf board.

⬢Carefully pull the hotend assembly out of the heatsink. Do not throw the parts away!

⬢At the same time pull the disconnected hotend cables from below the heatsink.

⬢By pressing the safety latch, unplug all remaining cables from the Dwarf board.

⬢Remove the heatsink assembly and set it aside.

⬢Remove the three M3x10 screws from the heatsink. Do not throw the parts away!

⬢Separate the heatsink and the print fan assembly. Do not throw the parts away!

⬢Remove the two M3x30 screws to remove the idler-swivel from the heatsink. Do not throw the parts away!

⬢Remove the idler-swivel from the heatsink. Do not throw the parts away!

⬢Using a universal wrench, remove the Fitting QSM-M5 by turning it counter-clockwise. Do not throw the parts away!

⬢Using a T6 Torx key, remove the M2.5x6rT screw. Do not throw the parts away!

⬢Carefully remove the Hall filament sensor. Do not throw the parts away!

⬢Using a T6 Torx key, remove the set screw from the bottom of the heatsink to remove the NTC thermistor. Do not throw the parts away!

⬢Pull out the NTC thermistor from the heatsink. Do not throw the parts away!

⬢Very carefully pull the filament sensor out from the heatsink using the needle-nose pliers.

⬢Using a T6 Torx key, remove the hotend grub screw from the heatsink. Do not throw the parts away!

⬢Now, you can throw the old heatsink into the bin.

⬢Heatsink (1x)

⬢Hall filament sensor (1x)  removed in previous steps

⬢M2.5x6rT screw (1x) removed in previous steps

⬢Hotend grub screw (1x) removed in previous steps

⬢Filament sensor assembly 1x) removed in previous steps

⬢Place the Hall filament sensor into the similarly shaped pocket in the heatsink.

⬢Fix it with M2.5x6rT screw. Tighten it very carefully, you can crack the electronics board.

⬢Insert the grub screw into the slot closer to the bottom of the heatsink. See the picture.

⬢Insert the Prusa ball holder assembly into the heatsink. Make sure the steel ball part is closer to the side of the heatsink.

⬢Push the assembly into the heatsink.

⬢Idler-swivel assembly (1x) removed in previous steps

⬢M3x30 with spring screw (2x) removed in previous steps

⬢NTC thermistor (1x) removed in previous steps

⬢NTC thermistor grub screw (1x) removed in previous steps

The color of the idler-swivel may be different. The part is the same. 

⬢Tighten the idler-swivel with two M3x30 screws.

⬢The tip of each screw should be flush with the plastic part on the other side.

⬢On the extruder motor side, insert the NTC thermistor into the hole in the heatsink.

⬢The NTC thermistor must be placed in the centre of the heatsink. See the picture.

⬢Insert and firmly secure the M3x4T grub screw using a T6 Torx key. Screw it all the way in. Applying more force may cause permanent damage to the thread.

⬢Motor assembly (1x) removed in previous steps

⬢Gearbox assembly (1x) removed in previous steps

⬢PG-assembly-adapter (1x)

⬢Carefully place the heatsink assembly onto the motor assembly. Look at the picture.

⬢Dismantle the gearbox assembly into its component parts:

⬢Using a paper towel clean all the parts from grease.

⬢In the following steps, we will reassemble the entire gearbox assembly to ensure proper installation.

⬢Attach the PG-assembly-adapter on the PG-assembly. Note the pockets for the gears in the adapter.

⬢Slide the PG-ring onto the adapter.

⬢Grasp the entire assembly in one hand so that it can be rotated with the PG-ring.

⬢With the other hand, slide the PG-ring onto the PG assembly in a wobbling motion (move the PG-ring left and right repeatedly) - a quarter turn is enough.

⬢Stop when the surfaces of the gears are approximately flush with the surface of the PG ring.

⬢Attach the main-plate on the heatsink. Note the orientation of the part. Use the cutout for the socket screw as a guide (lower left corner).

⬢Maintain the position of the PG-assembly and attach it on to extruder motor shaft.

⬢Make sure the PG-ring perfectly fits on the socket set screw.

⬢Very gently and freely rotate with the whole PG assembly (PG-assembly-adapter, PG-assembly and PG-ring) until it drops down so that there is minimal gap between the assembly and the main-plate. Do not push on the assembly.

⬢Remove the PG-assembly-adapter.

⬢Attach the PG-assembly-adapter back on the PG-assembly again to verify that all parts are properly seated.

⬢Rotate with the PG-assembly-adapter. The PG assembly must be easy to rotate without having to exert much force.

⬢Remove the PG-adapter. You will no longer need it during assembly. We recommend keeping it for maintenance.

⬢Ensure that the PG-assembly is not sticking out above the PG-ring. It should be positioned lower than the level of the PG-ring's surface or at the same level as the ring.

⬢There must be no gap between PG-ring and the Main-plate. If you see a gap, remove the planetary gear assembly and repositon it again.

⬢Open the Prusa Lubricant. Using the opposite side of the cap, puncture the hole in the opening of the tube.

⬢Apply a small amount of Prusa Lubricant all around the PG-ring and PG-assembly teeth.

⬢Using a paper towel, wipe off any excess lubricant on the front surfaces.

⬢Place the PG-case on the gearbox.

⬢Insert three M3x25 screws into the PG-case, but do not tighten them completely. They will be tightened later.

⬢Close the idler-lever and lock it in position with the idler-swivel.

⬢Plug the load cell sensor cable into the Dwarf board.

⬢Plug the filament sensor cable into the Dwarf board.

⬢Plug the heatsink thermistor cable into the Dwarf board.

⬢Print fan assembly (1x) removed in previous steps

⬢M3x10 screw (3x) removed in previous steps

⬢Fitting QSM-M5 (1x) removed in previous steps

⬢Align the three metal spacers with the holes in the heatsink, make sure the board and fan cables are guided below the top spacer before you attach the heatsink, so that they are not pinched.

⬢Insert and secure three M3x10 screws. Don't pinch any cables!

⬢Connect the print fan to the print fan connector.

Starting from September 2024, you may receive a new black Fitting M5-4. The assembly and functionality remain identical to the blue one.

⬢Mount the Fitting QSM-M5 on the top of the heatsink.

⬢Gently tighten the Fitting QSM-M5 with a uni-wrench.

⬢Hotend assembly (1x) removed in previous steps

⬢Hotend fan (1x) removed in previous steps

⬢M3x20 screw (2x) removed in previous steps

⬢Nextruder body (1x) removed in previous steps

⬢M3x40 screw (2x) removed in previous steps

⬢Insert the heater and the thermistor cable under the heatsink. Look at the picture.

⬢Insert the nozzle into the heatsink and push it all the way into the heatsink.

⬢Rotate the heaterblock as in the picture. There must be approximately 35° - 40° angle to avoid damaging the hotend cables.

⬢Maintain the position and using the TX 8 Torx key carefully tighten the grub screw to secure the hotend.

⬢Close the dwarf-cover-door and turn the Nextruder.

⬢Attach the nextruder-body to the Nextruder.

⬢Insert and secure two M3x40 screws.

⬢Insert the hotend fan between the heatsink and the extruder body. Look at the picture.

⬢Insert and secure two M3x20rT screws.

⬢Connect the hotend fan cable to the Dwarf board.

⬢Connect the hotend thermistor cable to the Dwarf board.

⬢Connect the hotend heater cable to the Dwarf board.

⬢Close the dwarf-board-cover on the Nextruder.

⬢Gently tighten the screw.

⬢Attach the cable connector into the top of the Nextruder.

⬢Insert the semi-transparent PTFE tube into the fitting on the Nextruder. Push it all the way in.

⬢Hook up the keyhole openings in the flexible plate of the cable bundle onto the screw heads and push it up to correct the position.

⬢Using a T10 key tighten the marked two screws.

⬢From the back of the X-carriage, attach the extruder assembly to the X-carriage. See the correct orientation of the extruder.

⬢Hold the extruder and secure it by inserting and tightening two M3x12b screws into the top screw holes. Do not fully tighten the screws at the moment!

⬢Insert and tighten two M3x12b screws to the lower holes in the X-carriage to secure the extruder assembly. Do not fully tighten the screws at the moment!

⬢Fully tighten all four screws diagonally to secure the extruder assembly.

⬢Snap the x-carriage-cover back onto the X-carriage. You must feel a slight "click" to ensure the cover fits on the part.

⬢Guide the extruder cable bundle with the PTFE tube freely over the printer to its rear side.

⬢Turn the printer, so the back side of the printer is facing you.

⬢Locate the long metal profile (tch-mounting-insert) in the back of the top extrusion. It has five threaded openings in it.

⬢There is a screw protruding from the xl-dock-cable-router. The screw must be attached to the third threaded opening on the long metal profile. Look through the rear metal sheet to check if the cable holder is lined up with the correct opening.

⬢Push the 2.5 mm Allen key all the way through a hole (bottom left in the pattern) in the rear metal sheet as well as through the plastic part until you reach the screw. Tighten it up.

⬢Loosen two screws on the cover slightly. No need to remove them completely. Push the cover to the right and gently remove it from the screws.

⬢Connect the Nextruder cable to the upper slot labeled DWARF 1.

⬢Attach the antenna-holder to the screws and push the cover to the left. Tighten the screws.

⬢From the rear side of the printer, plug in the PSU cable.

⬢Turn the power switch ON (symbol "I").

⬢Run the tests from the Control - Calibration & Tests menu.

The wizard will test all important components of the printer. The whole process takes a few minutes. Some parts of the wizard require direct user interaction. Follow the instruction on the screen.

⬢Plug in the printer and turn it ON.

⬢Now we need to simulate the movement of the gearbox. On the LCD screen, navigate to Filament - Unload filament.

⬢As soon as the extruder's movement finishes, tighten the three M3x25 screws on the PG-case in the correct order (shown on the picture).

⬢Then loosen the screws slightly and repeat the process, tightening the screws in the correct order. This ensures that the gearbox is seated correctly.