Captive Ring Lift

The captive ring lift was an experiment to create an adjustable stage for a new smartphone microscope.

Design requirements:
-Stage must stay flat and not wobble under load, when static or moving
-Incremental, smooth, one-handed height-adjustment
-No glue or support material
-Reversible disassembly, replaceable parts.
-Opening (window) for backlight

I chose to go with the screw mechanism as it is a very common and recognizable operation that doesn’t require explanation. Similarly, the use of pegs in assemblies is something with which most are familiar (even if it is octagonal pegs and teardrop-shaped holes). I have found they require less tuning and are more forgiving regarding tolerances between printers.

There are files for three pegs of different diameters. I find the 4.0mm pegs work well for me in PETG when printed without brim. My Ender 3 PLA prints required a brim and 3.9mm pegs worked well after trimming the excess plastic. You may have to print a few of each size