It seems the poor heatsink cooling might be one of the sources of heat-creap and clogging. Looking at the 7 cooling fins and the 4 slots in the front cover, it seems like a very poor design where every second slot is blocked.
It would seem like an upgrade would be to remove the offending middle three ribs that block these slots. Snip snip. Easy. Shouldn’t have a big effect structurally.
What do you think?
Check our presentation here: Findings and solution for the Snapmaker J1 clogging problem - #108 by Mechanikus
I had measured the temperature drop inside the hotend there since I wanted to know if replacing the fan with the more powerful one from the E3D V6 would help. Cooling works perfectly fine though - the only obstacle I could find was that the critical area just above the thin area of the heat break is cooled slightly worse if you fail to follow the instructions and do not insert the hotend until the bottom of the heat sink is flush with the lower end of the housing.
Already tried it and it made no difference.
The problem with heat creep appears to solely be due to the design of the heatbreak. Compared to an E3D V6 heatbreak, or a Slice Engineering Copperhead, there are are lot of small differences in the J1 heat break that add up to a very long transition zone between hot and cold. The heatsink is already more than cold enough. The problem occurs in the space between the heatsink and the heater block.
