This tutorial will cover 3 specific maintenance operations for the 3D printing tool:
- Replace a nozzle
- Replace PTFE liner
- Replace heatbreak
Included with each H-Series Machine is a small kit containing the most commonly damaged or replaced parts.
This kit contains the following;
- PTFE tubing for the Standard and High Temp Extruder
- Insulation for the Standard and High Temp Extruder
- Heat break for the Standard and High Temp Extruder
- 0.4mm nozzle
- Probe stylus
- A 1.5" x 1.5" square of 600 grit sandpaper
Note: After any of these operations, it is good practice to make sure to re-calibrate the tool.
Nozzle replacement
- Heat the extruder to 180°C (or the printing temperature of the current filament.)
- If there is currently filament in the extruder, retract about 20 mm.
- Carefully grab the hot end with a pair of pliers, careful not to damage the insulation, and remove the nozzle with a 7 mm driver (in the H-Series toolkit).
- Replace with new nozzle and tighten down to approximately 8 in-lbs of torque or until snug. If the nozzle is too loose then plastic will leak out of the bottom of the heater block and over-tightening can damage the heater block. Use pliers to ensure that the heater block stays in place and does not spin with the nozzle.
PTFE replacement
- Remove any filament that is currently in the extruder. Make sure to let the Hotend cool down at this point.
- Remove the hotend by unscrewing the 2 stainless steel M3x5 mm socket head screws that hold the heatbreak to the heatsink.
- Use the sandpaper provided in the quick recovery kit to grab the PTFE tube and pull it out of the heatsink.
- Insert the new PTFE tubing into the extruder, ensuring that the PTFE opening lines up with the drive gear rollers.
- Re-fasten the hotend back to the heat sink (or replace it if it is damaged) and torque the 2 socket head screws to 4in-lbs.
Heatbreak Replacement
We've designed the H-Series to have easy hotend and nozzle changes.
- Make sure the filament is retracted from the nozzle (approx 20mm)
- Rotate the turret so you have access to the nozzle (call up Tool2 to access Tool1, T3 -> T2, T4 ->T3, T5->T4, T1 -> T5)
- Make sure the tool is still hot (>180C) and loosen the nozzle with the 7mm nut driver
- For safety, LET THE HOTEND COOL DOWN.
- Remove the (2) M3x5 socket head screws that attach the heatbreak to the extruder body. By hand, unthread the heatbreak from the heater block. (Note: if a leak occurred in the hotend and plastic made its way to the threads, it may be necessary to perform this step while the hotend is still hot. Leather gloves are highly recommended.)
- To reassemble, thread the new heatbreak into the heater block until the back surface of the threaded portion of the heatbreak is approximately flush with the back surface of the heater block (see diagram below). Before reinstalling the hotend to the extruder body, check that the PTFE liner is not discolored. This is more likely with a standard hotend (shown on the right in the diagram). If the PTFE does look badly discolored (i.e. the browned region extends more than approximately 1 mm), replace it before continuing with the rest of the assembly.
- Reinstall the hotend to the extruder block with the (2) M3x5 socket head screws. Install these screws gradually, tightening by half turns while alternating between them. Finish by torquing them to 6in-lb.
- Thread the new nozzle in by hand to get it started, then tighten it down with the nut driver (Use pliers to apply counter-torque to keep the hotend straight. Apply approximately 8in-lb of torque. At this point, check that the hex of the nozzle is not in contact with the surface of the heater block. As shown in the diagram above, there should be a gap of 0.5~1mm. If this is not the case, disassemble again and thread the Heatbreak into the heater block by another one-half turn.
- Heat the hotend to over 200C, and snug the nozzle again to ensure a good seal to the Heatbreak. Apply 8in-lb of torque.