My son wanted some better airflow for his treadmill. I made him a fan-holder arm that we could screw onto the treadmill frame.

I utilized a maker connector, and a light can clamp - I use these light can clamps frequently. I think they are made for stage lights. They are very handy.. good for bigger pipes.

Also pictured is a similar thing I did for fastening a water bottle cage to my elliptical.