GT2 20-80 Zähne Zahnrad-Pulley Drucker Riemenscheibe ,Breite 7mm ,3D-Drucker

Most Cartesian and CoreXY 3D printers use 20-tooth pulleys on the stepper motor shafts for the X and Y axes. If you are replacing a worn pulley, match the tooth count of the original. If you are building a custom drive system, a 20-tooth pulley paired with a GT2 belt gives approximately 40mm of linear travel per motor revolution — a common baseline for desktop printers. Larger tooth counts (e.g., 36–80 teeth) are typically used as idler pulleys or in reduction stages for CNC and robotics applications.

NEMA 17 stepper motors typically have a 5mm diameter output shaft. Select the 5mm bore variant for a direct fit. If your motor has a D-cut shaft, the set screw will lock against the flat to prevent rotation. For NEMA 23 motors, the shaft is commonly 6.35mm (1/4 inch) — select the 6.35mm bore variant accordingly.

Yes. The GT2 2mm pitch tooth profile is identical for both open-loop (cut-to-length) and closed-loop (loop belt) GT2 timing belts. The 7mm belt width matches standard GT2 belts sold for 3D printers. Ensure the belt width of your replacement belt also matches 7mm for proper flange engagement.

Slide the pulley onto the motor shaft and align it with the belt path. Tighten the set screw(s) using a hex key (typically 1.5mm or 2mm) until the pulley is firmly locked. For D-cut shafts, rotate the pulley so the set screw contacts the flat before tightening. Avoid over-tightening, which can deform the bore. Check alignment with the belt and idler pulleys before running the motor.

The aluminum alloy body with anodized surface treatment provides good resistance to oxidation and light chemical exposure typical of workshop environments. Anodizing creates a hard oxide layer that protects the base metal from moisture and mild abrasion. For high-humidity or outdoor applications, periodic inspection is recommended to ensure the set screw and bore remain free of corrosion.

Yes, larger tooth-count variants (e.g., 36–80 teeth) are commonly used as idler or tensioner pulleys in belt routing systems. In this case, you would typically mount the pulley on a smooth shaft or bolt using a bearing insert. Note that these pulleys are sold without bearings — if you need a bearing-mounted idler, you will need to source a compatible bearing separately and press-fit or slip-fit it into the bore.

The tooth count directly affects the linear travel per motor revolution. A 20-tooth GT2 pulley moves the belt approximately 40mm per revolution, while a 40-tooth pulley moves it approximately 80mm per revolution. A higher tooth count increases speed but reduces torque and positional resolution. For CNC routers requiring fine detail, a 20-tooth drive pulley is typical. For faster travel axes or larger machines, a higher tooth count may be appropriate.