The lk1 has been a very productive unit for our projects and we are still using the stock extruders and hotends. Maybe the hotends have been changed out but overall they are stock. The tubes get changed about every 40 hours but most of the time if there is an issue with the extrusion it's because the hotend fan fails or loses efficiency.
What happens is the tube melts inside the hotend and collapses on the filament.
Our slicer setup extrudes the filament out completely after a print so we don't get the issue with filament not coming out but if we stop a print we always retract the filament. This is a good way to feel the condition of the tube, pushing the filament into the hotend or pulling it out is a great measure as to the condition of the tube. A normal condition would allow the filament to move right down to the nozzle. This is a learned experience but after a while you can start to tell that there is going to be a problem.
Here is an example of a regular creality hotend and then a custom one. The stock ones work great but the never ending quest to gat better results causes changes that are not always better.
The advanced hotend took some time to get used to, the barrel and the tip have to connect and tightly or it will leak.
Upgraded hot end
You might venture out and purchase a specialty hot end, sometime with a extruder as a unit. This is one here and we will show the differences. Using this is ok , not a must have, and at 30 bucks probably can live without, all the so-called technology really not necessary.
Our journey using the LK! as the basis machine has finally brought us to upgrading the extruder by changing out the seperate assembly with the long tube to a combined unit. There are many options here but our intent is not to break the bank going silly and buying the latest greatest and to just buy a inexpensive solution that works. We tried several and even purchase one expensive small compact one only to return it, we ended up testing 2 units that were both 40 dollars and similar but different in parts. We actually went with the unbranded one because of the location of the motor behind the assembly with the load slot in front
It's only been a week with our upgrades on the extruder hotend combo. So far it's been a mixed bag. One of the creality units had a motor that didn't work, no big deal but still. I have both units running, the red unbranded one twice, it's been hit or miss, I mean 1 great print, then failure, then half ass print. I calibrated the units and am still doing minor adjustments but overall I think it will be positive. The best part for me is the location of the input for the filament, the original setup has you searching behind the left vertical brace for the input hole, this in itself is worth the 40 bucks. Time will tell, I have several tasks stacked up. But as I go along I am still relying on the good old setup on several machines printing quality parts
These direct drive upgrades are working out great. I am running 3 machines with them, the best one out of the three is the creality version, it's about 40 bucks. I would say it's worth it but I am also still running 3 machines with the stock setup and they still produce good parts so there's no motivation to change them out. Using a quality main board like the duet wifi and good quality filament does the trick. Haven't had any jam ups in a long time. Alot of the success is extracting the filament when the print is complete
Red fan clone bowden tube is 91.5mm as removed