I am getting constant clogs and I'm not sure what to try next. I'm used to running a direct-drive hotend, and this bowden tube assembly is unfamiliar to me.
In Stage 6 Step 9 the instructions say "Fix two PC4-M6 couplings onto the heatsink of the switching hotend." Also it says "If you have a low temp side, make sure that the PTFE tube has been pushed all the way to the nozzle. If not, the hotend will get clogged! It should slide approximately 65mm from the top of the coupling." This isn't making sense to me. Does the PTFE tube somehow fit differently in a low-temp hotend as opposed to the high-temp version?
I didn't find any PC4-M6 couplers in my kit, so I procured my own. The M6 thread on the coupler does screw into the hotend as expected, but the bottom end of that fitting is WAY too small for the PTFE to push in through it. I tried drilling this out to 4mm, and now I can push approximately 65 mm of PTFE below the top of the PC4-M6 coupler. Unfortunately, this didn't stop the clogging.
It may be that I'm misunderstanding something very basic here. Can anyone give suggestions on what to try to stop the clogging? It's been a fair amount of work putting this on my printer and I sure don't want to give up on it now.
I will answer my own questions here in case those answers may be helpful to others.
The problem with the clogs was caused by my printer setup in Cura. When you set up a new machine in Cura it defaults to 3mm filament. However, the DSH and most hobby-level printers use 1.75 mm filament. Once I fixed that problem, I got past the clogs.
The kit does include PC4-M6 couplers which have sufficient internal diameter to work with the supplied bowen tubing. I just lost track of mine and substituted some other PC4-M6 couplers which caused problems. If you use the ones that come with the kit, they should work fine.