Trackballs That Can Spin

By Xah Lee. Date: . Last updated: .

trackball designs that allow the ball to spin.

Trackballs with Ball Transfer Unit

Ball-Bearing Trackball Design Concept-Keycon 2014
testing EM7 BTU [2022-05-19 image source]
Slimblade Trackball [2022-05-19 image source]

BTU stands for Ball Transfer Unit. It's a large ball sitting on lots smaller balls, for most smooth rolling mechanism.

BTU Ball Transfer Unit ms4f
[2022-05-19 image source]
Slimblade Trackball with modified ball bearings. [2022-05-19 image source]
Ploopy Trackball with 13oz Steel Ball and BTU's comparison to Elecom DEFT Pro
Jan 18, 2022

Left: Kensington Expert Mouse modified with Zirconium Oxide bearings.
Right: default ruby bearing. [source reddit, by boomskats]
GameBall with ball from Microsoft TrackBall Optical. Ball is polished using NOVUS 7100 3 part polishing kit. The effect last a few days. [by Skyl3r 2021-10-21]
moroe diy fx trackball. Ball spin
Oct 22, 2021

Here's idea using air bearings:

Make vacuum pre-loaded spherical air bearings without special tools
Dec 22, 2019
Applied Science

True Spin Balls

As far as i know, only these 2 truly spins.

ITAC mouse-trak Industrial trackball
Feb 9, 2016

ITAC Mouse-Trak Trackball

at 1:55, ball spin.
CH Products DT225 USB trackball •Jul 18, 2014
David Kolib

DT225 Trackball

Trackball Spin Test

L-Trac Trackball (this is an older model with flat side cylindrical roller) [Video by George 2021.]
CST L-Trac Redesigned Rollers
Aug 1, 2016

L-Trac Trackball

Elecom HUGE Trackball , ball spin test, right out of the box. [video by Emily E]

spinning scroll rings

scroll ring spins. modified bearing to the ring. Kensington Expert Mouse [2022-05-19 image source]

Xah Keyboard Guide