V2 TPU Spool Riser for AMS HT

Version 2 of my TPU spool riser for the AMS HT, updated to address a spool over-rotation issue observed in V1. This behaviour was initially reported by some users. While not commonly encountered, I was able to reproduce it through testing. During fast travel moves, the spool could occasionally spin excessively, leading to filament unravelling and potential tangling. V2 introduces optional damping to mitigate this, and redesigns the model to print fully support-free using optional but recommended legs.

Alternate designs (Same design but with added desiccant storage)

• V2 AMS HT Desiccant Storage + TPU Spool Riser
• V2 AMS HT Desiccant Storage + TPU Spool Riser + Funnel Saver

What’s New

• TPU damper legs – add slight resistance to control spool rotation
• Support-free design – no supports required
• Modular slots – allows optional structural and damping add-ons
• Improved inlet saver – supportless design

Add-Ons

• Inner slots (structural legs) – optional support to reduce long-term bowing, especially when using drying
• Outer slots (TPU dampers) – help prevent filament unravelling during fast moves

Damper legs are designed for Bambu Lab spools (67 mm width, 66.2 mm fitted gap). STEP file included for customisation.

Key Benefits

• Reduces risk of filament tangling
• Maintains smooth, reliable extrusion
• No extra parts required (reuses AMS HT roller)
• Quick, tool-free install

Assembly

1. Remove all brims and clean up printed parts
2. (Optional, recommended) Install TPU damper legs (outer slots)
3. (Optional, recommended) Install structural legs (inner slots)
4. Remove the rear roller from the AMS HT 
5. Insert the riser into the AMS HT
6. Place the roller through the spool
7. Slot the spool + roller into the riser
8. Follow the recommended TPU setup instructions provided by Bambu Lab

Installation Note
Ensure the riser is fully seated during installation. The TPU damper legs include a slight rearward bulge designed to maintain contact with the AMS HT side wall and prevent backward movement when the spool engages. Take care when inserting, as the bulge aligns beneath an internal ledge and may catch if not positioned correctly.

Notes (Read Before Printing)

• Damper legs are recommended to prevent spool over-rotation during fast moves
  • Do not assume the damper legs are perfect for every setup. sers should trial them and adjust if needed using the provided STEP files as a reference. The included ones work for me and are very light (~0.5 g of filament), so they can be iterated quickly.
• Structural legs help reduce long-term bowing, especially when using the drying function
• Riser must be printed in a material with adequate heat resistance if used with the drying function
• Designed around Bambu Lab spool dimensions (67 mm width)
• STEP file included for adapting damper legs to other spools

Updates

V2 - Initial Release.

V2.01 - Added a print profile for a slightly longer set of damper feet.

V2.02 - Added in two cut-outs to allow drying using the standard filament tie-off method without needing to remove the model.

V2.03 - Thickness of frame and cut outs adjusted to increase strength