Mellow VzBoT GT2 Aluminium Idler Kit – 20T 5mm Bore Timing Pulley

Mellow VzBoT GT2 Aluminium Idler Pulley Kit – Precision-Machined for 2GT Gates Timing Belt

Engineered specifically for the VzBoT 3D printer, this Mellow GT2 Idler Kit delivers exceptional belt-tracking accuracy and smooth motion control. Every toothed idler in this set is produced using special tooling supplied by Gates — the same manufacturer behind the belts themselves — ensuring a perfect tooth profile match and eliminating the belt-skip issues commonly caused by off-spec pulleys.

Why Mellow GT2 Toothed Idlers?

Standard aftermarket pulleys are often manufactured with looser tolerances, leading to subtle mismatches between belt teeth and pulley grooves. This can introduce micro-vibrations and positional errors that degrade print quality. Mellow's idlers are CNC-machined to a surface finish of Ra 0.4 µm, providing ultra-smooth belt engagement and consistent tension throughout the full range of motion.

• Toothed Idlers gently cup the belt's teeth as they travel around curves, preventing tooth deformation and extending belt life.
• Smooth (Toothless) Idlers feature correctly profiled flanges and clearances to maintain constant belt tension in ways that plain bearings cannot replicate.
• Made from lightweight, durable aluminium alloy for minimal rotational inertia and long service life.
• No assembly required — ready to install straight out of the box.

Specifications

Package Contents

SET 1:

• 6 × Toothed Idlers (With Tooth)
• 2 × Smooth Idlers (Without Tooth)

SET 2:

• 4 × Toothed Idlers (With Tooth)
• 4 × Smooth Idlers (Without Tooth)

Compatible Products for Your Workshop

Pair your VzBoT build with other precision tools and workshop accessories available in our store:

• 10-Pack 65mm Oscillating Multi-Tool Saw Blades | Carbon Steel
• Adjustable Woodworking Compass Layout Gauge for Carpenters
• 5-Pair Nitrile Work Gloves – Anti-Slip Full Finger Safety

Learn more: OSHA guidance on hand and power tools

Frequently Asked Questions

Q: What 3D printer is this VzBoT GT2 Idler Kit designed for?

A: This Mellow GT2 Idler Kit is specifically customized for the VzBoT 3D printer. It is compatible with 2GT Gates Timing Belts of 6 mm width and uses a 5 mm bore, making it a drop-in upgrade for VzBoT motion systems.

Q: What is the difference between the toothed and smooth idlers included in the kit?

A: The toothed idlers are designed to mesh directly with the belt's teeth, guiding the belt smoothly around curves and preventing tooth wear. The smooth (toothless) idlers are flanged and clearanced to maintain constant belt tension and redirect the belt's flat side without damaging it — each type plays a distinct role in a high-performance CoreXY or VzBoT motion system.

Q: Why are Gates-tooled teeth important for this aluminium timing pulley?

A: Using special tooling supplied by Gates ensures the tooth profile on the aluminium pulley precisely matches the Gates 2GT belt geometry. This minimises backlash, eliminates belt skip, and delivers consistent, repeatable positioning — critical for high-speed, high-accuracy 3D printing on platforms like VzBoT.

Q: Does this kit require any assembly before installation?

A: No. The Mellow VzBoT GT2 Idler Kit arrives fully assembled and ready to install. Simply mount the idlers into your VzBoT frame using the standard 5 mm bore mounting configuration.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.