Anti-Sag：Improved CORE One Extruder Cable Sag Solution: REMAKE

During use, I identified two areas where the original design could be improved to increase the overall robustness and reliability of the assembly.

Wire Tie Retainer Assembly

The original wire tie mounting clip did not remain securely fastened to the extruder, and the method used to secure the stainless steel wire tie to the mounting clip was somewhat flimsy and could loosen over time.

To address these issues, the wire tie retainer was redesigned while maintaining the overall geometry and functionality of the original part. The updated design incorporates M3 heat-set threaded inserts (3 mm thread × 4 mm length), providing a much stronger and more reliable fastening method.

The mounting clip was also redesigned with a slotted recessed pocket that allows the stainless steel wire tie to sit partially recessed within the body of the retainer. This provides a cleaner installation while helping prevent the wire tie from shifting under load.

The stainless steel wire tie is now secured using an M3 × 8 mm socket head cap screw threaded into a heat-set insert. A second M3 × 16 mm socket head cap screw, also threaded into a heat-set insert, securely clamps the mounting clip to the extruder. This significantly improves retention and prevents the assembly from loosening or shifting during operation.

These changes result in a substantially more robust mounting solution that is easier to assemble, more resistant to vibration, and provides a secure, long-term attachment for the stainless steel wire tie.

Part B – Swingarm Clip with PTFE Clip

During use, it was also determined that the original Part B – Swingarm Clip with PTFE Clip could lift out of the swing arm mounting slot during printer operation. While the clip continued to retain the PTFE tube, its engagement with the swing arm was not as secure as desired.

To improve retention, the clip was redesigned with a tighter interference fit where it engages the swing arm mounting slot. This revised geometry provides a more positive mechanical engagement while still allowing the clip to be installed and removed without excessive force.

As shown in the comparison image, the original design is on the left and the revised design is on the right. The updated geometry significantly reduces the possibility of the clip lifting or becoming dislodged during high-speed print movements and repeated filament changes, resulting in a more secure and reliable attachment to the Prusa Core One swing arm.

NOTES: 

When installing the 4 mm heat-set threaded inserts into the wire tie retainer, it is recommended to place a spacer between the two retaining ears to prevent them from deforming during installation. A standard hex nut, as shown in the accompanying photographs, works well for this purpose. As the insert is heated into the plastic, heat is conducted into the surrounding material, temporarily softening the retaining ears. Without a spacer supporting them, the ears can flex inward or become permanently deformed. Supporting the ears during insert installation maintains the correct spacing and ensures proper fit and function of the finished part.

Summary of Design Improvements

• Wire Tie Retainer

  • Redesigned using M3 × 4 mm heat-set threaded inserts.

  • Stainless steel wire tie secured with an M3 × 8 mm socket head cap screw.

  • Mounting clip secured to the extruder with an M3 × 16 mm socket head cap screw.

  • Added a recessed slot for the stainless steel wire tie, providing a cleaner installation and improved retention.

  • Significantly improved resistance to loosening and vibration.

• Part B – Swingarm Clip with PTFE Clip

  • Redesigned with a tighter interference fit to the Prusa Core One swing arm mounting slot.

  • Improves retention of the clip on the swing arm while maintaining compatibility with the original design.

  • Reduces the likelihood of the clip lifting or becoming dislodged during printer operation.

Print in PETG, or something a little resistant to higher temps

No supports needed

Step Files added for further redesigns.