Handlebar clamp mount for Blackburn Flea bike headlight. The inner diameter is 24mm to accommodate some rubber padding, so just cut up a piece of an old tube or something and mount it!
This requires a little bit of work after printing:
First, the hinge hole is small and I used 16gauge steel wire as a hinge pin, so I had to drill the hold out a little. Best done with a drill-press, but you can make do without.
Next, the light clip itself is a separate part from the clamp. I designed it this way both to avoid using rafts and supports, and to align the layers for best possible strength.
I welded the clip onto the clamp using a soldering iron and extra filament, but if you have a good solvent/glue it would probably be strong enough. I also used an x-acto knife to open up the space the clip fits into because tolerance of my print was not where I expected.
Finally, get a 5/16" hex nut and machine screw, and put it on your bike!