I have been threatening to build a DIY pool heater for a couple of years now. I have half a dozen of those cheap Intek filter/pumps that pump nowhere near enough water for a large pool, so I plan on using that as the circulator. I will connect the pump to a black, 100' garden hose to act as a solar heater. To do that, I needed a way to couple the pump's 1.25" hoses to the garden hose. I didn't want to cut the hose and use barbed connectors like other people often do... I wanted the hose to remain intact. I have yet to figure out how to design threads in CAD, so I am relying on this fantastic pair designed by codemite for the threaded portion. To use this, you will need to print one each of the male and female couplers.
Another Sketchup Model - Debunking the Myth that Sketchup is Useless in 3D Printing