This is a quick little adapter that I drew up to adapt a 1¼" pool hose to fit a 1½" connector on a pool filter's [Waste] port. This isn't really designed for the high pressure so, while you could use it on the intake side of a pool pump, I would not recommend it on the high pressure output side. For the waste side, though, this works just fine and gets the job done. Plus, it's a quick solution to a problem when you need something in the middle of the night on a weekend out in the sticks :)
My first version sprunk a few pinhole leaks due to not using enough walls and too little infill, so since I had to reprint it anyway, I went ahead and modified the design a tad. I got rid of the taper fit on the output side and made it a straight fit on which you can clamp the hose. The file for this is _notaper.
Another Sketchup Model - Debunking the Myth that Sketchup is Useless in 3D Printing
You can print this with or without supports, There is a small overhang on the inside, but I printed it without supports and there was just a couple of stray strands... no big deal. Printed at 0.3mm layer height, no supports, 20% infill and 60mm/sec print speed, this takes just over 2 hours.
Ok... scratch all of that. After a week or so, I developed small pinhole leaks. This time around, I printed with 100% infill, 0.2mm layers and 40mm/sec print speed. Let's see that little sucker leak now!