# Hotend Disassembly (/docs/all/maintenance/hotend-disassembly) A properly maintained tool head is crucial for consistent print quality. Over time, filament residue, clogs, or worn-out components can cause print failures. Read the [Safety - Before You Begin](/docs/v4/reference/safety-before-you-begin) article to understand the hazards involved in working on the Vision Miner 22IDEX V4 – including electrical, thermal, mechanical, and chemical risks. All procedures in this wiki are provided as recommendations only. By choosing to follow any procedure, you do so at your own risk. **Start here:** this procedure covers full hotend disassembly for maintenance, inspection, or component replacement. If you only need to change the nozzle, see [Nozzle Change](nozzle-replacement) for a faster procedure. For clog clearing without full disassembly, see [Clearing Clogged Hotend/Unclogging](unclogging). ## Tools and Materials [#tools-and-materials] * **Wrenches**: * 7 mm (or 9/32") for nozzle removal * 12 mm or adjustable wrench for holding the heat block * **2 mm Hex Driver** (commonly used for fan shroud/extruder and grounding wire screws) * **Pliers or Adjustable Wrench** (to hold the heat block during nozzle changes) * **Boron Nitride/Thermal Paste** (for the heater, sensor, nozzle, heat break) * **Spare Components** (optional): * Nozzle * Heat break * Heater cartridge * Temperature sensor (PT1000) * PTFE tube * **Protective Equipment**: * Heat-resistant gloves * Safety glasses - [Wiring Schematic](../../v4/reference/wiring-schematic) - [Filament Loading/Unloading](../printing/load-filament) - [Clearing Clogged Hotend/Unclogging](unclogging) ## 1. Removing Filament [#1-removing-filament] There are two ways to remove the filament: **automatically** through the Web Interface, or **manually** by hand. Either works, so use whichever is more convenient. 1. **Preheat** the hotend to the filament's printing temperature. 2. **Unload** the filament using one of the methods below. **Automatic (Web Interface).** With the hotend hot, use either of these controls to retract the filament: * **Tool unload button:** next to the active tool (**Left Tool** / **Right Tool**), press the unload button that indicates loaded filament. This retracts the filament for that tool. * **Extrusion Control:** press **Retract** in the Extrusion Control section, slightly lower in the Web Interface (100 mm at \~7 mm/s). **Manual.** Preheat the hotend, then push the extruder lever to the position shown below to release tension on the filament, and pull it out by hand. 3. **Reference**: If unsure, see the [Filament Loading/Unloading](../printing/load-filament). Molten plastic will help prevent clogging or filament residue in the nozzle and heat break. If the filament is stuck or the extruder motor clicks without moving the filament, see [Filament Won't Retract](#filament-retract) in the Troubleshooting section. ## 2. Removing the Nozzle (While Hot) [#2-removing-the-nozzle-while-hot] 4. **Heat** the hotend to printing temperature (or slightly lower, e.g., 20–30°C below standard printing temp). 5. **Secure** the heat block with pliers or an adjustable wrench. 6. **Unscrew** the nozzle **clockwise** (looking up from the nozzle tip) using a 7 mm wrench. 7. **Caution**: The metal components will be extremely hot. Wear heat-resistant gloves and avoid contact with any heated surfaces. 8. **Cool Down**: After nozzle removal, power off and allow everything to cool to a safe handling temperature. Removing the nozzle hot prevents hardened filament from binding the threads. This reduces the risk of damaging the heat block or nozzle. If you cannot remove the nozzle or suspect a clog, see [Nozzle Still Clogged](#nozzle-clogged) in the Troubleshooting section. ## 3. Power Off [#3-power-off] 9. Power off the printer by **unplugging it from the wall** to ensure complete electronic safety. ## 4. Removing the Fan Shroud [#4-removing-the-fan-shroud] The same two screws hold both the fan shroud and the wire guard. 10. Use a **2 mm hex** driver to remove the two screws holding the fan shroud in place. 11. Carefully move the fan shroud aside, together with the fan, so it does not get in the way during the rest of the disassembly. The wire guard stays in place and does not need to be removed. ## 5. Remove Grounding Wire (Lug Style Crimp) [#5-remove-grounding-wire-lug-style-crimp] Before proceeding to remove the hotend assembly, you must disconnect the **grounding wire** at the hotend. 12. Locate the **lug-style crimp** attached to the hotend body (see picture below). 13. Using a **2 mm hex** screwdriver, remove the screw holding the lug in place. 14. Carefully set the grounding wire and lug aside for later reinstallation. This wire is essential for proper grounding. Ensure it only contacts the hotend metal surface to avoid electrical issues. ## 6. Removing the Hotend Assembly [#6-removing-the-hotend-assembly] You usually do not need to disconnect the hotend wires. The heater, temperature sensor, and grounding wires all meet at the **distribution block** shown below. Leave them connected, and disconnect one only if it gets in your way during the next steps. 15. If a wire is stretched tight and gets in the way as you remove the hotend, disconnect just that wire using steps 16-18. If no wire is in the way, skip to step 19. 16. Using a **2 mm hex** screwdriver, press the **orange spring-loaded tab** inside the distribution block **opposite** the wire you want to remove. 17. **Support the distribution block** from the back so you do not put force on the tool head. 18. With the tab pressed, **gently pull** the wire straight out. **Do not force it.** If you do disconnect a wire, take a photo or label it first to track polarity and where it reconnects. See the [Wiring Schematic](../../v4/reference/wiring-schematic) for reference. 19. **Extruder Front Plate**: * Using a **2 mm hex** driver, **fully unscrew** the two marked screws shown in the photo. Remove them completely. 20. **Slide Out the Hotend**: * Pull the hotend toward you (forward). * If the hotend doesn't slide out easily, gently shake it from side to side while pulling it towards you. * Check for stray filament or debris that might prevent smooth removal. ## 7. Disassembling the Hotend [#7-disassembling-the-hotend] Once the hotend is free from the extruder, you can break it down into its core parts. 21. **PTFE Tube**: * Carefully pull the PTFE tube out with tweezers, taking care not to damage it. It should come out with little effort. * If it resists, skip this step for now and remove the tube after you unscrew the printed interface plate (next step). * Inspect the tube: it should be flush and cut to the correct length. Replace it if it is damaged or too short. 22. **3D Printed Interface/Adapter**: * Using a **2 mm hex** driver, remove the two screws holding the interface plate. * Separate the interface plate from the radiator. 23. **Cooling Fan**: * Unscrew 2 screws and remove the fan. 24. **Radiator**: * Loosen the screw on the radiator and remove it. 25. **Heat Break**: * Unscrew the heat break. If it will not come loose by hand, [see the heating tip below](#heating-stuck-parts). 26. **Heater Cartridge & Temperature Sensor**: * **Fully unscrew** the set screw that holds the temperature sensor and the heater cartridge in the heat block. Do not just loosen it, take it all the way out. * Gently slide out the heater cartridge and temperature sensor for inspection or replacement. If they will not slide out easily, [see the heating tip below](#heating-stuck-parts). These parts can be hard to remove because the boron nitride paste that improves heat transfer also makes them stick. **Do not force them.** 1. Plug the printer back in and heat the tool to about **150–200°C** to soften the residue. 2. Wearing **heat-resistant gloves**, hold the heat block only with a gloved hand and carefully work the part free. 3. When finished, let the printer cool down, then **power it off** before continuing. The metal parts will be hot. Work slowly and carefully. * **Grounding Wire**: Check if the grounding wire is **worn out**, **burned**, or **excessively bent** due to heat exposure. Replace if damaged. * **Fan Wires, Sensor Wires, Heater Wires**: Ensure no fraying, burning, or other damage. * **Tip**: Apply **Boron Nitride/Thermal Paste** to threads and surfaces (nozzle, heat break, sensor, heater) as needed for heat conduction and easier future removal. ## 8. Reassembling the Hotend [#8-reassembling-the-hotend] Reverse the disassembly steps: 27. **Install or Replace the Temperature Sensor & Heater**: * Lightly coat each component with thermal paste. * Slide them into the heat block. * Secure with the set screw (do not overtighten). 28. **Attach the Heat Break**: * Thread the heat break into the heat block **finger-tight**. Avoid applying torque to the thin heat break walls. * If using a **Copperhead®** or similar, refer to the manufacturer's instructions for correct orientation/fit. 29. **Reattach the Radiator**: * Slide the heat break into the radiator. * Tighten the set screw carefully. 30. **Reattach the Cooling Fan**: * Attach the fan to the radiator. 31. **Reattach 3D Printed Interface Plate and PTFE Tube**: * Attach the interface plate to the radiator. * Reinsert PTFE tube. Ensure correct length and flush fit. This prevents gaps that cause clogs. For more details on sensor and heater installation or wiring inspection, see [Hotend Temp Sensor & Heater Maintenance](hotend-heater-sensor). ## 9. Reinstalling the Hotend Assembly [#9-reinstalling-the-hotend-assembly] 32. **Slide the Hotend** back into the extruder grooves. 33. **Secure** it with the original screws on the front plate. 34. **Reconnect the Grounding Wire**: * Fasten the grounding wire to the hotend body using the **2 mm hex** driver. This wire **must not** touch any other metal components except the hotend itself. If it does, Z-Probe (ground detection) may fail, and you risk damaging your printer. 35. **Reconnect Other Wires**: * Reconnect each wire to the same terminal it came from. The **heater cartridge and temperature sensor are not polarity-sensitive**, so their orientation does not matter. The **fan wires are** polarity-sensitive - use your reference photo or the [Wiring Schematic](../../v4/reference/wiring-schematic) to connect the fans the right way around. If you unplugged any wires at the distribution block during disassembly, reconnect them now **exactly as they were originally**, matching the correct positions and polarity. If you left the wires connected, you can skip this step. 36. **Reinstall Fan Shroud & Wire Guard**: * Replace the fan shroud using the 2 mm hex screws. * Make sure wires, including the grounding wire, are tucked properly under the wire guard without excessive bending or contact with other metal parts. ## 10. Final Steps & Nozzle Installation [#10-final-steps--nozzle-installation] 37. **Initial Tightening**: * Thread the nozzle in **counter-clockwise** (looking up from the nozzle tip) by hand or at **\~1 Nm** torque. * Hold the heat block with a wrench to avoid twisting the heat break. 38. **Heat Soak**: * Heat the hotend to your normal printing temperature. * Let it sit for a few minutes to ensure all components expand and seat properly. 39. **Final Tightening**: * Once hot, use your wrench again to **slightly re-tighten** the nozzle (still around 1–1.5 Nm max). * This helps **prevent leaks** around the threads. 40. **Perform a Test Extrusion**: * Load filament to confirm a clear path and ensure no jams or leaks at the nozzle. For a detailed walkthrough of nozzle changes, see [Nozzle Change](nozzle-replacement). 41. **Perform a Calibration**: * In the Web Interface, open the `Macros` tab and run `Auto Calibration`. * Follow the on-screen instructions. This runs the full calibration sequence, including Tool Height and Z-Offset, which you need after hotend work. See the [Auto Calibration](/docs/v4/calibration/auto-calibration) guide for the full procedure. If you encounter issues after reassembly: * **Under-extrusion or poor layer adhesion** – see [Poor Layer Adhesion or Under-Extrusion](#poor-adhesion) * **Incorrect temperature readings** – see [Incorrect Temperature Readings](#temp-readings) * **Heater not working** – see [Heater Not Working](#heater-not-working) * **Ground faults** – see [Electrical Ground Issues](#ground-issues) ## Troubleshooting [#troubleshooting] If you encounter issues during or after the procedure, work through these common problems: **Symptoms:** * Filament stuck in the hotend during unloading. * Extruder motor clicks or grinds but filament does not move. **Solutions:** 1. Verify the hotend is fully heated to the filament's melting point (check the temperature in the Web Interface). 2. Manually retract using the extruder lever – press the lever down to release tension on the filament, then pull the filament out by hand. 3. If the filament still won't move, the nozzle may be partially clogged. See [Nozzle Still Clogged](#nozzle-clogged) below. **Symptoms:** * No filament extrudes after reassembly. * Under-extrusion or inconsistent flow. * Filament cannot be loaded through the nozzle. **Solutions:** 1. Remove the nozzle again (while hot) and inspect the opening. Use a nozzle cleaning needle or wire to clear the hole. 2. Test extrusion **without the nozzle** installed. If filament flows freely from the heat block threads, the clog was in the nozzle itself – clean or replace the nozzle. 3. If filament does not flow even with the nozzle removed, the clog is in the **heat break** or **PTFE tube**. See [Clearing Clogged Hotend/Unclogging](unclogging) for the full procedure. 4. For persistent clogs in high-temperature materials (PEEK, ULTEM), perform a cold pull or torch cleaning (steel nozzles only). **Symptoms:** * Layers do not stick together. * Gaps between perimeters or infill. * Weak or brittle prints. **Solutions:** 1. Check for **partial clogs** – remove the nozzle and inspect for blockages. Clean or replace the nozzle. 2. Verify the **PTFE tube length**. The tube must be flush against the top of the heat break inside the radiator. If the tube is too short, a gap forms and causes clogs. Replace the PTFE tube if damaged or incorrectly cut. 3. Confirm the nozzle is **properly tightened** after heat-soaking (see [10. Final Steps & Nozzle Installation](#10-final-steps--nozzle-installation)). A loose nozzle allows filament to leak around the threads instead of extruding cleanly. 4. Re-check the first-layer height with [First Layer Calibration](/docs/all/calibration/first-layer) to verify correct nozzle height. **Symptoms:** * Web Interface shows wildly incorrect temperatures (e.g., −3000°C, 2000°C, or "short to ground"). * Heater does not turn on. * Temperature fluctuates randomly. **Solutions:** 1. Check the **temperature sensor wiring**. Verify the sensor wires are connected to the correct terminals on the distribution block. Reversed polarity or loose connections cause incorrect readings. 2. Inspect the sensor wire for damage – frayed insulation, pinched cables, or corrosion at the terminals. 3. Verify the sensor is seated correctly in the heat block. The tip of the sensor should make firm contact with the bottom of the sensor hole. Loose sensors give inaccurate readings. 4. Check the firmware configuration. The PT1000 sensor requires a specific configuration in `config.g`. See the [Wiring Schematic](../../v4/reference/wiring-schematic) for correct wiring and configuration. 5. If the sensor reads consistently incorrect values (e.g., always 50°C too low), the sensor may be faulty – replace it. **Symptoms:** * Hotend does not heat up. * Temperature stays at room temperature even when heating is commanded. * Error message: "Heater fault" or "Heater timeout". **Solutions:** 1. Check **heater wire polarity and connections**. Verify the heater wires are connected to the correct terminals on the distribution block. Heater cartridges are polarity-insensitive, but loose connections prevent heating. 2. Inspect the heater wires for damage – frayed insulation, breaks, or corrosion. 3. Verify the heater cartridge voltage matches the printer's power supply. Vision Miner printers use **24V heater cartridges**. Using a 12V cartridge will result in slow or no heating. Check the label on the heater cartridge. 4. Use a multimeter to check **heater continuity**. Disconnect the heater wires from the distribution block, set the multimeter to resistance mode, and measure across the heater wire terminals. A typical 24V 60W heater cartridge should read approximately **9–10 ohms**. If the reading is infinite (open circuit), the heater cartridge is broken – replace it. 5. Check the mainboard heater output. If the heater cartridge and wiring are good but the heater still does not work, the mainboard output may be faulty – contact support. **Symptoms:** * Printer fails Z-Probe (ground detection) self-test. * Error message: "Z-Probe test failed" or "Ground fault detected". * Z-Probe reads incorrectly (see [Z-Probe Issues](/docs/all/troubleshooting/z-probe) for detailed Z-Probe troubleshooting). **Solutions:** 1. Inspect the **hotend grounding wire** (lug-style crimp). The grounding wire must contact **only** the hotend metal surface. It must **not** touch any other metal components – the belt bracket, the frame, the extruder motor, or any screws. 2. Check for **wire routing issues**. The grounding wire should have clearance from moving parts and should not be pinched or bent sharply. 3. Verify the grounding lug screw is **tight**. A loose screw causes intermittent ground faults. 4. If the grounding wire is damaged (burned, frayed, or corroded), replace it. 5. For persistent ground faults after checking the grounding wire, inspect the **Z-Probe circuit** (if applicable). See [Z-Probe Issues](/docs/all/troubleshooting/z-probe) for detailed diagnostics. ## FAQ [#faq] Yes. You can access the heater cartridge and temperature sensor set screws without fully removing the hotend assembly. However, full removal gives better access and makes it easier to inspect wiring, apply thermal paste, and ensure correct reassembly. For standard materials (PLA, PETG, ABS), disassemble and inspect the hotend every **500–1000 hours** of printing or when you notice clogs, under-extrusion, or inconsistent flow. For high-temperature materials (PEEK, ULTEM, carbon fiber composites), inspect every **200–300 hours** or after each major project. Regular maintenance prevents clogs and extends component life. Yes. After full hotend reassembly, run the **Auto Calibration** macro (`Macros > Auto Calibration` in the Web Interface). It performs the full calibration, including Tool Height and Z-Offset, which set the correct nozzle height and tool alignment. See the [Auto Calibration](/docs/v4/calibration/auto-calibration) guide for details. Tighten the nozzle to approximately **1–1.5 Nm** after heat-soaking (see [10. Final Steps & Nozzle Installation](#10-final-steps--nozzle-installation)). Do not overtighten – excessive torque can damage the heat block threads or the nozzle. Always hold the heat block with a wrench while tightening or loosening the nozzle to avoid twisting the heat break. The grounding wire is often routed too close to the belt bracket or frame. Bend the wire gently to create clearance, ensuring it only contacts the hotend lug. Use a zip tie (if needed) to secure the wire to the hotend wiring bundle, keeping it away from moving parts and metal surfaces. Do not bend the wire sharply near the lug – this can cause wire fatigue and breakage. Inspect the PTFE tube carefully. If the ends are clean, square-cut, and not heat-damaged (no browning or melting), you can reuse it. If the tube is too short, damaged, or has been exposed to high temperatures (above 250°C for extended periods), replace it. A damaged or incorrectly cut PTFE tube causes clogs. ## Support [#support] If you could not find an answer here, reach out to our [support team](/support).