Extruder seperation
I recently switched my nozzle from my .25 to the original .40. When I started to print there were cobwebs and droplets of "brown" PLA regardless of the filament colour. I poked and prodded and cranked the heat up to (carefully) scrape off the extruder before loosening and tightening the nozzle to make sure it was close. The problem remains. I took the fan off the front and discovered that there is a gap the width of my scaple handle (15mm or so) between the heat sink and the block the nozzle screws into. I've looked at my assembly book and really can't see what the gap should be. Attached is a picture which hopefully adds to the explanation.
RE: Extruder seperation
There should be some gap between there. The thing is, the heatbreak unscrews on both ends, into the block and into the heatsink.
If you take apart nozzle, block, heat break and heat sink, proper e3d assembly is as follows (after everything is cleaned):
First: screw the nozzle into the block, then untighten it by roughly half a turn.
Second: screw the heatbreak into the block from the other side, until it is snug against the nozzle.
third: screw all of that into the heatsink
fourth: tighten the nozzle when hot.
Hope that helps. (edit:spelling)
RE: Extruder seperation
You hotend was not reassembled correctly, and you have filament leaking out between the heatbreak and nozzle, eventually working its way out the top of the heater block and down into your prints. You can see the filament around the heatbreak neck in your picture. You need to follow the E3D instructions for reassembly carefully. In particular:
- The nozzle should be screwed into the heater block leaving a small gap between the nozzle hex and block.
- The heat sink should be hand screwed into the top of the heater block until it touches the nozzle inside. The small gap between nozzle hex and heater block should remain. At this point, the block is acting as a nut holding the heat break and nozzle together.
- The entire assembly should be tightened at 285C. Once tightened, a small gap should still remain between the nozzle hex and heater block.
If the nozzle hex is flush up against the block, or if you left a gap but didn't tighten the heat break all the way against the nozzle, you'll get that gap and corresponding leakage.
RE: Extruder seperation
Thanks guys. Was this just because I changed nozzles from .40 to .25 to .40? Because I printed for nearly a year with the original .40 and this was not an issue? I'll do the reassembly but is it something I can expect to happen again?
RE: Extruder seperation
Thanks everyone. I took the nozzle off, made sure all the gunk was melted away and reassembled it with care to make sure stuff was tight (but not too tight). I've done a couple of short prints without issue and will work up to an overnight job.
You are a wonderful community. 🙂