5M Idler Pulley
5M is also known as HTD5M, calling it HTD5M refers to its specific "curvilinear" or "arc" tooth profile, which is designed to prevent "jumping" or ratcheting under high loads and provides more surface contact than older trapezoidal profiles. The Idler Pulley designed for use with a 15mm wide timing belt. It is commonly used as a tensioner or a slave drive pulley in CNC machines, 3D printers, and various automation builds.
Below is a detailed breakdown of its specifications and configurations:
Key Specifications
Pitch: 5.00mm (5M profile)
Tooth Profile: Arc (HTD 5M compatible)
Material: Aluminum (typically with a natural or sandblasted finish)
Belt Compatibility: Designed for 15mm wide timing belts (actual tooth width of the pulley is 16mm).
Type Options:
Toothed: Features teeth to match the timing belt profile (best for the "inside" of a belt loop).
Smooth (NO): A flat surface idler (best for the "backside" or smooth side of the belt).
The product can be ordered with different tooth counts, bore sizes (the inner diameter of the bearing) and also the width for different width of belts 10mm, 15mm, 20mm or 25mm .
Note: RobotDigg also lists availability for tooth counts ranging from 12T up to 50T upon request.
Typical Applications
Tensioning: Maintaining proper belt tension in linear motion systems.
Path Direction: Changing the direction of a belt loop without adding friction.
Heavy Duty Builds: Because it uses the 5M pitch (larger than the common GT2 used in desktop 3D printers), this is suitable for larger torque requirements, such as small CNC mills, heavy-duty camera sliders, or electric skateboards.
Summary of Dimensions
Tooth Width: 16mm (to allow clearance for a 15mm belt).
Total Width: Usually slightly wider than 16mm to accommodate the bearing flanges and housing.
Bore: Most standard versions utilize a 5mm bore, which fits common M5 bolts or shafts.
