Screw Jack 15-29mm

I originally made this as a door jam (for a rather awkward window) but it was too fiddly. 

If some grip is modeled into the outer faces i'm sure it can be used to prop something up or just be used as a fidget toy

To assemble:

• Screw in both inner and middle into the outer body with the recess for the locking rings faced down
• Glue the locking rings* in (these hold the bodies captive)

*Highlighted in green in 3rd image

Printing recommendations:

• Wall order inner to outer as the inner threads overhang
• Print seperately for smooth threads
• Print inner, middle and outer upside down for less overhangs