Pole Clamp mounting 19-26mm

I wanted to make camping lights using an off the shelf low cost plastic bulkhead like Eurolux B174 (https://www.eurolux.co.za/products/B174) but I needed a way to attach it securely in any direction to a pole of Gazebo or tent. So I designed this clamp to fit around a pole between 19mm-26mm, maybe even bit bigger, with a captive screw to tighten and loosen without the clamp falling out. But I can see many applications where you want a clamp to fit around a pole to fit something. 

Use a strong but somewhat flexible material like PETG or ABS. The screw thread should be vertical in Z axis for best quality, and that will also help strength of the clamp itself. Version 1 screw is a little thin so if there is interest I'll make one with a larger thread.