Nozzle and Heat break stuck in heater block
Recently I was trying to change the heat break on my printer when I discovered that both it and the nozzle were stuck in the heater block. I tried multiple methods for getting both of them out but none of my attempts worked. For the heat break I used a pair of pliers to attempt to gently unscrew it but I could not get enough grip. I thought that removing the nozzle might help as it seemed to make it easier in the past but I discovered the nozzle was also stuck. I used a pair of pliers to hold onto the heater block and a 7mm closed end wrench to attempt to unscrew the nozzle. I tried unscrewing it at temps ranging from 215-250. Also, when I first unloaded the filament before taking apart the hotend the filament did not come out cleanly and looked as it it left some filament behind (the filament I pulled out had a reverse dome shape on it). Now when I reassembled the extruder it is completely jammed. It seems to be jammed in the heatbreak because no new filament can reach the melt zone. Is there any way to remove both that jam and to safely remove the nozzle and heatbreak. Thanks.
RE: Nozzle and Heat break stuck in heater block
I had a similar experience trying to replace a stripped heater block. Everything had fused together over the course of my first year of "learning experiences" and everything had caramelized together. I wound up replacing the heater block, heartbreak, thermistor and heater cartridge.
I took the opportunity to upgrade to a titanium heat break and nickel-plated copper block. I applied some high temp thermal paste to the cartridges to ease future replacement and now protect everything with a silicone sock. I also keep spares on hand.
RE: Nozzle and Heat break stuck in heater block
Thanks for the reply. My problem is pretty similar and I still have not been able to fix my issue since posting. I think new parts are probably the best solution.
RE: Nozzle and Heat break stuck in heater block
I just dismantled and reassembled my complete hot end today. I removed the whole assembly from the printer according to these instructions. https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/easiest-way-to-get-to-filament-detector-on-a-mk3s/#post-225950
Once I had it removed, I labelled and cut the heater wires and the thermistor wires. This allowed me to move the assembly to the bench.
I warmed the block with a butane torch and then held the block with an adjustable wrench and removed the nozzle with a 7mm socket. I don't think mine was as tight as yours, so you might need to put some muscle behind it. Once I had the heater block and the nozzle removed, I double nutted the heatbreak with two 6mm-1.0 nuts and removed the heatbreak.
I then cleaned up the threads with a 6mm die for the heatbreak and nozzle, and a 6mm tap for the heatblock. You may want to warm the parts with the butane torch to soften the melted plastic to help clean it up.
Good luck
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