QIDI Plus4 friction reduced filament spool holder upgrade

The original filament spool holder of the QIDI plus4 printer does an adequate job, but in combination with some spool materials a slip-stick-effect can occur causing quite anoying sound emissions, which can easily be mistaken for a bearing failure in the motion mechanics. To avoid this, the ideal solution would be a replacement of the original spool holder with a version featuring ball bearings for example. I may add such a design later for printing TPU. However, a certain resistance to prevent the spool from rolling on its own via the friction of a sleeve bearing is in most situations beneficial. So this upgrade of the original holder with a friction reduced surface is a practical and easy solution.

I have recently come by a small testsample of a printable sleeve bearing plastic made by igus, the iglidur l150-PF Tribofilament (You can order testsamples of this on their homepage) and found this application to be a fitting test case. In order for the received amount of filament to be sufficient, I split the design in several parts of which only the sleeve surface is made of this particular filament, whilst the rest can be made of any regular printable plastics.

A quick note on the print settings for the iglidur l150-PF filament, as it turned out to be quite a bi*** to be printed. I guess the properties of beeing non-sticky during use yet to bond well during print were kinda hard to combine:

• Use otherwise standard PLA settings and change the following values
• Nozzle temp: 260°C
• Bed temp: 70°C
• All velocities: 40mm/s (yes, that slow!)
• Set the nozzle cooling to 40% and all others to off.
• Reduce the volumetric flow to 91% of the PLA-standard (this value can also be easilychanged live during the print in case you dont want to fool around with the settings too much)

How to print:

All parts should be printed with their rotational axis upright. No support is needed anywhere. Use the settings of whatever material you choose for the other parts and the above given ones for the iglidur filament. The gaps to snap-fit the parts together are tuned into the design with PLA in mind, though. ( In case you want to print the core and sleeve as one part, such a file is included as well.)

How to assemble:

Look at the provided pictures. Take off the fastener cap. Put the two “Spring-Ring” parts on the holder, then preassemble the new sleeve surface to the core and put them as one on the holder, finally secure them all with the fastener cap again. In case you need to remove the new sleeve for mounting spools with tight axial holes, the “Spring-Ring” parts may stay on, permanently. I have used higly elastic PLA (eSUN ePLA-ST) for those - in case you run into problems mounting them without permanent deformation, try the included versions with a larger opening.