It's too many years since I've seen one, I don't know how far off it could be after 1000's of moves, another engineers project.
But they are good for slightly dirty wet environment.
Creep of the plastic housing, and the shaft that holds the bearing would be my main concern for a DIY version.
I've only seen aluminum block used with precision threaded shaft, I forget the name, Carr Lane or another supplier used to have a precision shaft SHCS.
I can't locate it found this: [www.carrlane.com]
Found it: precision shoulder screws
[www.mcmaster.com]
But they are good for slightly dirty wet environment.
Creep of the plastic housing, and the shaft that holds the bearing would be my main concern for a DIY version.
I've only seen aluminum block used with precision threaded shaft, I forget the name, Carr Lane or another supplier used to have a precision shaft SHCS.
I can't locate it found this: [www.carrlane.com]
Found it: precision shoulder screws
[www.mcmaster.com]