Worm Gear Set (28:1 Ratio, 8mm REX Bore Worm)

Competition eligibility

Legal for FIRST Tech Challenge (FTC) and FIRST Robotics Competition (FRC). Eligibility is set by each season's game manual — check the current rules before you compete.

This 28:1 Ratio Worm Gear Set is an excellent way to slow things down and increase torque! Worm gear sets are also a popular choice for applications that are not able to be backdriven. While you can use this set outside of 3120 Series Channel, the sizes of gears are tailored for the 43mm of internal width.

The "Worm"

The worm is the stainless steel component that is intended to be driven by an 8mm REX shaft. The 8mm REX bore of the worm creates a positive drive so there’s no chance of slipping between it and the shaft that’s driving it. The set-screws are not necessary to have if the worm itself is captured by the framework it’s installed within but they come in handy in situations where the worm is not limited axially. The length of the worm is 33mm so that the combination of it, a thrust bearing on each end, and a radial bearing on each end fits perfectly inside the 43mm channel width.

The "Worm Gear"

The worm gear is the brass component that is intended to be driven by the worm. It will rotate 28X slower than the worm. This gear has the standard Sheen Robotics and thefirsttool 16mm pattern on it so that you can pick the output shaft diameter and profile that best fits your project. The output shaft will not be able to rotate unless it’s being driven by the worm which is one of several benefits of a worm gear reduction.

Technical drawing