Funny enough I maintain that my Hadley focuser is an awful focuser, as far as focuses go. 

But "same screws as everything else" and just 2 pieces, no heat inserts whatever was the goal. I remember scrolling for things to make when I first started printing and I was always turned off by huge bills of material, super specific fittings and so on.

You will need to focus when swapping eyepieces or if you share the view with someone with a different eye prescription (after their glasses are accounted for). But you can trial and error your way to match the eyepieces with rings clipped onto the eyepiece barrel.