Here is a picture of my hardened steel 0.6mm hotend assembly. I bought a role of PA6-CF and I’m learning to print with it. This hotend is clogged with the stuff, and my usual tricks for removing PLA don’t work. I think this hotend might be a total loss. Is it cost-effective to try and fix it? Or should I junk it.
It also seems bent. I would try to salvage it, removing the fan and heat the hotend with a heat gun to melt most of it and clean with a rag (beware of burns…). If heat gun cannot achieve high enough temperature, use a soldering torch but you can easily melt the aluminum heatsink so be careful. When it’s melted enough and cleaned enough, try to get your heater and thermistor out to salvage them if at this point they’re still salvageable. Rest of the remaining nylon can certainly be cleaned with solvent and a wire brush.
What happened to the silicone sock? When this happens, it’s often that the sock is cut at some place and let the melted filament goes under it. I don’t see in your picture that the melted filament is coming from the top but if it is, as the nozzle seems bent, it may have developped a crack below the heatsink, if that’s the case, scrap it.
It does look bent in the photo. I just inspected the actual part, and it must be a trick of the photography. The real unit doesn’t look bent. The silicone sleeve didn’t get damaged. I have split the sleeve before, that was not the case here.
Thank you for the advice. I can try cleaning the outside with a glue gun. I don’t think I have a torch anymore. What really worries me is the length of filament stuck inside the assembly.
When it’s clean, filament inside should not an issue especially with a 0.6 nozzle. You can start doing a cold pull on the hotend itself (heat the smallest allen key provided with a lighter, insert it from the heatsink side, let it cool and pull). Install the hotend and load filament. If the extruder slips, remove the hotend again and only connect it and leave it hanging, heat to 260°C minimum and you can then force by hand a new filament through the hotend (you may want to wear gloves to hold the heatsink) until it comes through cleanly.