This is a filament guide to help retain tension on the filament when using external spools and spools over the print head. This guide prevents the filament drifting outside the spool and causing tangles and failures.  

The model has eyelets in 3 sizes (26,36 and 46mm) and should fit a variety of spool holders / cross beams. There are pips (dentents) on the cross beam to secure the width and optional pins are provide to provide extra security.

Suggest printing in PETG for strength but not required. no bearings or external parts. 

Instructions: 

• Print two arms with the appropriate eyelet size
• slide onto your spool rail / holder with arms on either side of the spool.
• Insert the cross bar in the sockets. Pips (detentes) should be spool facing so the smooth taurus shape receives the filament. 
• Secure with pins if necessary. 
• Feed filament through the hole.

The pips are a bit oversized to account for shrinkage / warpage / material variation. They may need slight filing to fit perfectly (don't over file).

Hopefully you will have care free TPU printing.

Pictured with this external TPU holder [https://makerworld.com/en/models/2711160-p2s-x2d-tpu-holder-lightweight-simple-design#profileId-3002063](https://makerworld.com/en/models/2711160-p2s-x2d-tpu-holder-lightweight-simple-design#profileId-3002063)