GT2 Zahnrad 2GT 28-58 Zähne Riemenscheibe Breite 11mm Pulley für CNC 3D-Drucker

The tooth count determines the pulley's pitch-circle diameter and, combined with your motor pulley, sets the drive ratio. For most CoreXY and Cartesian 3D printers, 20T motor pulleys paired with 20T idler/driven pulleys give a 1:1 ratio. Larger tooth counts (e.g., 40T–58T) are used as driven pulleys when you need torque multiplication or a specific linear-motion resolution. Calculate pitch-circle diameter as: PCD = (Teeth × Pitch) / π = (T × 2) / π mm.

A plain bore relies on one or two set screws pressing against the shaft to transmit torque. This works well for light-to-medium loads but can slip under shock or sustained high torque. A keyed bore (K 3 / K 4 / K 5 mm) uses a machined keyway that mates with a key on the shaft, providing a positive mechanical lock that prevents rotational slip regardless of torque spikes — preferred for CNC spindle drives and robotic joints.

Yes. These pulleys use the GT2 / 2GT tooth profile with a 2 mm pitch, which is the industry-standard geometry for GT2 open-loop and closed-loop timing belts. They are compatible with 11 mm wide GT2 belts. Do not use with HTD, T2.5, or other pitch profiles — tooth geometry differs and will cause premature wear or belt skipping.

Measure your motor or drive shaft diameter with a digital caliper. Common stepper motor shaft diameters are 5 mm (NEMA 17) and 6.35 mm (1/4 in, common on NEMA 23). For keyed shafts, also measure the keyway width and depth to confirm the K dimension matches. If your shaft is between standard sizes, choose the next smaller bore and ream or machine to final size.

These are drive pulleys designed to be fixed to a rotating shaft. For idler use (free-spinning on a bolt or pin), you would typically use a flanged bearing or an idler pulley assembly instead. Using a drive pulley as an idler without a bearing will cause rapid bore wear and inconsistent belt tension.

Most CoreXY designs (Voron, RatRig, etc.) use 20T pulleys on the motor shafts. If you are building a custom gantry or replacing a worn pulley, match the original tooth count to maintain your steps-per-mm calibration. If you are intentionally changing the ratio for finer resolution, recalibrate your firmware's steps/mm accordingly after swapping pulleys.

GT2 belt drives are well-suited for CNC router X/Y axes operating at typical rapid traverse speeds. For high-speed spindle drives or applications exceeding the belt's rated tension, verify the belt's dynamic load rating against your system's peak force. The 11 mm belt width provides greater load capacity than 6 mm variants, making these pulleys a solid choice for medium-duty CNC motion stages.