Runice 2GT Toothed Idlers

Choose your belt width from the dropdown.

A toothed GT2/2GT idler pulley with a 5 mm bore and a 20-tooth profile, built for compact 3D-printer and CNC motion systems. Both variants share the same tooth form, bore and 15 mm flange diameter — the only difference is the belt path width and the resulting overall height.

Why use a toothed idler here?

• Matches the belt tooth form instead of forcing the belt around a smooth bearing surface.
• Built around two bearings with flanges to keep the GT2 belt tracking cleanly.

Which variant do I need?

• 6 mm — the standard choice for most 6 mm GT2 motion belts.
• 9 mm — for builds that specify 9 mm-class belts, where the wider belt is used for extra stiffness.

Match the idler to the belt already in your BOM. A 9 mm idler will not track a 6 mm belt properly, and a 6 mm idler physically will not take a 9 mm belt.

Variants

Shared specifications

• Manufacturer: Runice
• Tooth profile: 2GT / GT2, 20T
• Bore: 5 mm
• Overall flange diameter: 15 mm
• Construction: toothed pulley body with 2 bearings and 2 flanges
• Finish: silver

Use and fitment

Use this anywhere your design calls for a 20T toothed GT2 idler with a 5 mm bore, selecting the variant that matches your belt width.

Gotchas

• Not a drive pulley: this is an idler, not a shaft-mounted pulley for transferring motor torque.
• Match the belt width. Choose the 9 mm variant if the belt path is wider, the 6 mm variant if it is not.
• Do not clamp the bearings axially. Use the correct spacers/shims so the idler spins freely after tightening.