This solution is for replacing a single hot end on a v2 printer.
Not sure if you have a v1 or v2 style HD printer? Check here: HD V1 or V2
- HDL, HD or HDx printer
- Replacement JR or JRx hot end (single)
- 4mm allen wrench
1) Turn on the printer with the power switch on the back panel
2) Heat the nozzle up to 315 degrees and completely remove the filament from the printer.
3) Turn the printer off with the power switch and unplug the power cord
4) Wait for the nozzle to cool to room temperature before moving to the next steps (5+ minutes)
5) Use the 4mm allen wrench to unscrew the six M6 screws from the back panel. Set aside the back panel.
6) Remove the bolt from the extruder assembly, and open the latch.
7) Remove the white threaded bolt from the extruder assembly.
8) Remove the grey wire from the extruder assembly clasp
Separate the grey cord from the extruder assembly motor wires (shown in red, green, blue, and yellow.)
9) The gray cord runs from the hot end all the way to the RAMBo board. Follow it down towards the board and it will split into 3 sets of wires.
Make a note of where these wires are plugged in, a camera is useful for this. Unplug all 3 of the wires from the board with the connectors attached to the ends of the wires.
You will be unplugging 3 wired plugs, as indicated in the diagram below with red arrows:
- One for the heater on the hot end (Heat 0)
- One for the fan on the hot end (Fan 0)
- One for the thermistor on the hot end (Thermistor T0)
10) If there are zip ties holding the hot end in place, cut and remove them. Be careful not to bend the rods during this process. Remove the hot end from the X axis bearing. To do this, bring the hot end up off the X axis bearing in an arc from left to right, using the Y axis bearing as a pivot point.
11) Remove the hot end from the Y axis bearing. To do this, bring the hot end up off the Y axis bearing in an arc from the back of the printer to the front.
The hot end should now be completely detached from both bearings.
12) Set the old hot end aside. Be careful not to bend the rods during this process. Take the new hot end and attach it to the Y bearing. Now attach the hot end to the X bearing. The hot end should snap down securely onto both bearings, and should now be securely in place.
13) Replace the gray cord into the clip on the side of the extruder assembly. Wrap the extruder motors around the grey cord for better cable management.
14) Plug the wired connectors from the hot end into the Rambo board at the appropriate locations.
15) Plug the power cable back in and turn the printer on. If your VIKI LCD screen says "Error: Min Temp", that means that the thermistor is not plugged in, or that it is plugged into the wrong port. Confirm that the Viki screen does not say "Error: Min Temp".
16) Print the calibration file for your printer. The file can be downloaded by clicking the following link.
This file will print 2 rectangles around the bed. Each rectangle should should have lines that are merged together completely, as in the photo below.
When the calibration rectangle is printing, do the following:
Check to see the hot end temperature is reading correctly (240 degrees).
- Check to see the hot end fan working
- Check to see that the hot end heats
17) Once the calibration print has been run correctly, put the back panel on the printer. Secure the back panel in place with the 6 screws. You are now ready to print the files of your choice.