Pololu Wheel for Micro Servo Splines (21T, 4.8mm) - 40×7mm, Black, 2-Pack

These black plastic wheels have silicone tires and measure 40 mm (1.57″) in diameter. They mount onto micro servo splines with 21 teeth and a 4.8 mm diameter, such as the splines on FEETECH’s FS90R micro continuous rotation servos and FT90R digital micro continuous rotation servos. This product is a pair of wheels.

Overview

These wheels are great for robotics, custom RC vehicles, or any other project you need to get rolling. They measure 40 mm (1.57″) in diameter and are designed for use with micro servos with 4.8 mm diameter splines with 21 teeth, such as FEETECH’s FS90R micro continuous rotation servos and FT90R digital micro continuous rotation servos. The combination can serve as a small, inexpensive, and easy-to-control drive system for a miniature robot. The wheel presses onto the servo spline just like a typical servo horn, and the small screw included with the servo accessory pack for mounting servo horns should be used to hold the wheel in place. The included silicone tires are also available separately.

60 mm and 40 mm Pololu Wheels for Micro Servo Splines on FEETECH’s FT90R and FS90R micro continuous rotation servos.

60 mm and 40 mm Pololu Wheels for Micro Servo Splines (21T, 4.8mm).

Product specification update (16 Nov 2021): The original product name and documentation for this wheel incorrectly said it was intended for splines with 20 teeth when it really is intended for servo splines with 21 teeth. We have now corrected this in our documentation. Nothing about the product itself or its compatibility with our FS90R and FT90R servos has changed.

Other wheel options

We have similar wheels available in different sizes and colors and with different spline compatibilities:

Alternatives available with variations in these parameter(s): size color shaft type Select variant…

Pololu Wheels for Standard and Micro Servos – 40, 60, 70, and 90 mm diameters.

We also carry an array of wheels compatible with 3mm D shafts:

Alternatives available with variations in these parameter(s): size color Select variant…

Black Pololu Wheels with 90, 80, 70, 60, 40, and 32 mm diameters (other colors available).

Pololu Wheels with 90, 80, 70, and 60 mm diameters in three colors: blue, red, and yellow.