GT2 Timing Belt Pulleys & Synchronous Belts — Precise Motion Control for Makers and Builders
When your 3D printer skips steps, your CNC router loses position, or your DIY robot arm drifts off-axis, the culprit is almost always a worn or mismatched drive pulley or belt. This listing brings together GT2 timing belt pulleys (35T, 36T, 38T, 40T, 42T, 45T tooth counts) and GT2 synchronous belts — both ring-closed loops and open-ended lengths — so makers, engineers, and workshop builders can source the exact combination they need in one place.
The pulleys are machined from aluminum alloy with a smooth-tooth GT2 profile and are available with bore diameters from 5 mm (0.20 in) to 14 mm (0.55 in). Belt widths are 6 mm (0.24 in) and 10 mm (0.39 in). Ring-closed belts range from approximately 98 mm (3.86 in) to 1,524 mm (59.99 in) in circumference; open-ended belts are sold by the metre.
Typical use cases include GT2 belt and pulley kits for RepRap and Ender-series 3D printers, X/Y-axis drive systems for desktop CNC routers, stepper-motor synchronous drive assemblies for robotics, and replacement timing belt pulleys for laser engravers and pick-and-place machines.
⚙️ Compatibility: GT2 2 mm pitch profile. Fits standard GT2 belts with 6 mm or 10 mm width. Verify bore diameter and tooth count before ordering.
✅ Key Features of These GT2 Timing Belt Pulleys and Synchronous Belts
🦷 Multiple Tooth Counts
Choose from GT2 35T, 36T, 38T, 40T, 42T, and 45T pulleys to match your gear ratio and axis travel requirements precisely.
📏 Wide Bore Range
Bore options from 5 mm to 14 mm (including 6.35 mm / ¼ in and 12.7 mm / ½ in imperial sizes) cover most stepper and servo motor shaft diameters.
📐 Dual Belt Width Support
Both 6 mm and 10 mm belt widths are stocked, letting you match the pulley to your existing belt without adapters or spacers.
🔄 Ring-Closed & Open-Ended Belts
Ring-closed GT2 loops (98 mm–1,524 mm circumference) and open-ended belts sold by the metre give you flexibility for fixed-loop and custom-length drive systems.
🏗️ Aluminum Alloy Pulley Body
Lightweight yet rigid aluminum construction keeps rotational inertia low while maintaining dimensional stability under continuous duty cycles.
🔩 Set-Screw Retention
Each pulley includes a set-screw bore for secure shaft fixation, preventing slippage during rapid direction changes typical in 3D printing and CNC routing.
📐 Technical Specifications — GT2 Timing Belt Pulleys & Synchronous Belts
| Belt Profile |
GT2 (2 mm pitch) |
| Tooth Counts (Pulleys) |
35T, 36T, 38T, 40T, 42T, 45T |
| Bore Diameter Options |
5 mm, 6 mm, 6.35 mm, 7 mm, 8 mm, 10 mm, 12 mm, 12.7 mm, 14 mm |
| Belt Width |
6 mm / 10 mm |
| Pulley Material |
Aluminum alloy |
| Belt Type |
Ring-closed loop / Open-ended (sold per metre) |
| Ring Belt Circumference Range |
98 mm – 1,524 mm (3.86 in – 59.99 in) |
| Flange |
See variant options |
| Surface Finish |
See variant options |
| Weight |
See variant options |
❓ Frequently Asked Questions
How do I choose the right tooth count for my application?
The tooth count determines your drive ratio and axis travel per motor step. For most desktop 3D printers (e.g., Ender, CR-10, Prusa-style), a 20T pulley is standard, but 35T–45T pulleys are used when a higher gear ratio is needed for torque multiplication or when the motor shaft is positioned farther from the belt path. Match the tooth count to your motion system's design specification or use a belt-drive calculator to confirm steps-per-mm.
Which bore diameter should I select for my stepper motor?
Measure your motor shaft diameter with calipers before ordering. Common NEMA 17 stepper shafts are 5 mm; NEMA 23 shafts are typically 6.35 mm (¼ in) or 8 mm. This listing offers bores from 5 mm to 14 mm, including the 6.35 mm and 12.7 mm imperial sizes frequently used in North American CNC builds. If your shaft is metric, choose the exact metric bore; do not assume a close imperial size will fit without modification.
What is the difference between 6 mm and 10 mm belt width, and which should I choose?
A wider belt carries more load and is less prone to lateral tracking issues. 6 mm belts are standard for lightweight 3D printer axes where low mass is critical. 10 mm belts are preferred for heavier CNC gantries, laser cutter carriages, or any axis where belt stretch under load is a concern. Always match the pulley width to the belt width — mixing widths causes uneven tooth engagement and accelerated wear.
Are these pulleys compatible with standard GT2 belts from other suppliers?
Yes. The GT2 profile is an open industry standard with a 2 mm pitch and a specific tooth geometry. Any GT2 belt of the correct width will mesh with these pulleys. Confirm that the belt pitch is GT2 (not GT3, HTD 3M, or MXL) and that the belt width matches the pulley flange width you select.
How do I select the correct ring-closed belt circumference?
Measure the center-to-center distance between your two pulleys, then calculate: Belt Length ≈ 2 × C + π × (D1 + D2) / 2, where C is center distance and D1/D2 are pulley pitch diameters. Alternatively, wrap a flexible tape measure around both pulleys in their installed position. Choose the ring belt size closest to your calculated length — slight tensioner adjustment can compensate for small differences of a few millimetres.
When should I choose an open-ended belt instead of a ring-closed loop?
Open-ended belts (sold per metre) are ideal for linear actuator systems where the belt is clamped to a carriage rather than forming a closed loop — common in CoreXY 3D printers, belt-driven linear rails, and custom conveyor builds. Ring-closed loops are better for fixed-distance drives such as extruder gears, rotary axes, and standard Cartesian printer X/Y systems where the belt path length is fixed.
How do I prevent the pulley from slipping on the motor shaft?
Each pulley uses a set-screw to clamp onto the shaft. For best results: (1) align the set-screw with the flat on the motor shaft if one exists; (2) apply a small amount of thread-locking compound to the set-screw threads; (3) tighten to the manufacturer's recommended torque for the screw size. Avoid over-tightening, which can crack the pulley hub on smaller bore sizes.
🛒 Select your typology, bore size, and belt width above, then add to cart.
