The Pitching In Build Instructions - Fling had a pretty good example. The full build is available on the Vex website. https://content.vexrobotics.com/vexiq/pdf/228-4444-335-Fling-Gen2-Rev1.pdf
Two gears were sandwiched around 2 x 3 supports to keep them aligned.
This was done on opposite sides to hold the whole assembly together.
