Wheels beat linear bearings, and here is why

Linear bearings are the obvious choice on paper. Under off-axis load, which is exactly what a heavy set produces, they bind. What we use instead, and how it ages.

On a spec sheet, linear bearings sound like the premium option for a moving carriage. Precise, low-friction, engineered. And on a test rig with a perfectly centred load, they are.

A heavy set is not a test rig. A lifter pushes slightly off-centre, shifts weight foot to foot, grinds through a sticking point. That produces off-axis load, force that is not perfectly aligned with the rail, and off-axis load is exactly what makes a linear bearing bind. You feel it as a catch or a notch partway through the travel, and it gets worse as the machine ages and the tolerances wear.

What we use instead

The Citadel hack squats run on wheels rather than linear bearings. Wheels do not care nearly as much about off-axis load, and they keep rolling smoothly whether the force is perfectly aligned or not. The carriage stays smooth through the whole range, loaded or empty, on day one and after ten thousand sets.

It is a less obvious engineering choice, and a better one for the job. That is the theme across the whole range: the answer that reads best on paper is not always the answer that holds up under a busy floor.