Just another PTFE tube guide for Bambu Lab printers

prusaprinters

[2024.01.16 - New refined 1.3 version]- Decreased the freedom for tube flexing to about 50% (The original part has way too big, the tube never used even the half of the range). - Increased the side limiter surfaces' radii in the open section: the tube now can move with less friction within the allowed range.- Small changes for better consistency of the 3D model (these do not have any effect on performance or usability) [2024.01.06 - Final touch]- I found that the cable chain and the Ptfe tube do not move together perfectly at all positions and removed one link from the cable chain (31 links instead of the initial 32 pieces).Now it is perfect.  :)BTW it looks like the middle screw issue was a singular issue with my printer.[Update 2023.12.12]I think I got the last piece of the puzzle. My design worked quite well, but once or twice I thought I still saw a popping move of the tube with the head moving along the right edge. This afternoon when I took apart the P1S for unrelated reasons (it gets a Noctua fan for the chamber and another for the mainboard) I finally caught the culprit: There is a screw at the middle of the right edge that protrudes below the edge so that the PTFE tube can be temporarily stuck in it and then pop over. When I removed the screw the movement became perfectly smooth all the way near the edge.I've attached a picture with the screw already removed.[2023.11.19]My printer is a P1S, so everything below applies to that. I presume all also can be applied to the X1C, but I can't be sure. I've tried to identify the problems with the freestanding PTFE tube as well as the new ones that come up when constraining the tube.So far, my understanding is:The main issue that triggered the creation of these tube guides is that AMS users often experience filament change problems because being unsupported, the PTFE tube can bend in small radii that prevent the AMS to push in or pull out the filament.A simple model by OurAngryBadger that fixes this issue is:https://www.printables.com/model/329942-bambu-x1-ptfe-straightener-bracket-ams-error-fixIt'll most likely solve the AMS problem, but also raises the tube. A lot of Bambu users implement some kind of extra chamber light that usually goes between the case and the top glass panel,  raising it by 10-15mm. In this case, the PTFE tube tends to go above the rim resulting in sudden popping moves when the printhead approaches or moves along the right edge of the work area (The tube is above the top edge of the printer case and pops back below only when the printhead is very close to the right edge.). This doesn't cause any error messages, but looks bad and I'm pretty sure it'll have consequences in the long run. Also, it'll have some effect on the finer details being printed.Designs like OurAngryBadger's remix of the original Bambu Lab version:https://www.printables.com/model/338073-bambu-x1-ptfe-extruder-bracket-ams-error-fixor https://www.printables.com/model/309088-bambu-lab-x1-ptfe-minimum-radius-guide/remixesby Mowcius (my favourite of the type) prevent this phenomenon by guiding the tube on a longer path. They also prevent the tube's flexing to the sides that creates another problem:When the printhead moves along the right edge, the tube and the guide stops the smooth rotation at a point and sticks to one side. The tube's bend radius becomes smaller as the head moves along the edge and eventually turns to the other side with a rather aggressive popping move.It looked so bad, that when I discovered it I stopped the print, removed the tube guide and restarted without it. Note that it only happens when the object you print makes the head long moves from back to front or front to back very close to the right edge.Going through all above I've come up with this design. It guides the tube in an exact position for the 1st 15mm upon exiting the printhead, but after that it only prevents the tube to reach an elevated position otherwise lets it flex freely. So far it solves all the issues I discovered.The design is new, so I’m sure its far from perfect. Please let me know about your experiences about it so I can keep on making it better.