Stick Clip for 3/4" (19mm) diameter tube.

This clip is a close approximation to the original clip that mounts to the tiller of my sailboat to hold the hiking stick when not in use.  However, it can be used anywhere you want to mount something to tubing (or mount tubing to something).  It is scaled to fit tubing that is .75" in diameter and the base is flat.  It snaps tightly to 1/2" pvc pipe which is .84" outside diameter.  You can scale it based on the approximate increase in tube diameter, for instance, 3/4" conduit (in the USA) is .925" o.d. or about 10% more than .84".  So you would print at 110% scale.   The picture shows a 110% scaled print clipped to 3/4" conduit.