11mm Steel Pachinko-Ball Spool Weight

1. Overview

This spool weight is designed to prevent slipping and free-spinning that can occur when the spool becomes lighter in multi-color systems such as the AMS or QIDI BOX. By attaching it to the spool, you can improve feeding stability and reduce noise and feeding errors.
Many existing models use AA batteries or large bolts, but this design uses 48 pcs of 11 mm steel balls (pachinko balls), providing over 300 g of stable rotational inertia.
The center is designed to accept a shaft, and it fits standard 1 kg spools with a width of up to 62 mm. Since it uses steel balls, it is safe even in heated spool-drying environments.
Note: Spool dimensions vary by manufacturer and production lot, so please measure your spool before use.

2. Features

• Uses 48 pcs of 11 mm steel balls (“pachinko balls”), which are easy to obtain (at least in Japan) and have consistent weight
• Total assembled weight: over 300 g (body + steel balls + M3 screws)
• Center hole: Ø54 mm. Fits spools up to 62 mm in width. Can be used as-is with spool holders up to Ø30 mm.

3. Required Additional Parts

• 11 mm steel balls (pachinko balls): 48 pcs
• M3 screws, 10–20 mm length: 4 pcs

4. Recommended Print Settings

• Material: PETG or ABS
  (Do not print with PLA if using a heated spool-drying box.)
• Layer height: 0.2 mm
• Infill: 20% or more
  (Increasing infill adds weight but also increases print time and material usage.)
• Wall count: 3 or more
• Supports: Not required
• If the M3 screw holes are too tight, adjust the slicer’s X-Y hole compensation.