The PVC connector concept has been done before, but when I started this project, I wanted something that was quicker to print, used less material, didn't require supports, and was strong and easy to fit.

After a few design iterations, I realised I was looking at the process the wrong way. All PVC connectors join around the outside of the pipes because the pipes are intended for channelling fluid, gas, or cabling. However, that's not necessary for structural use. That (now obvious) realisation changed the entire design principle and allowed me to create a simpler, more versatile connector that could be printed more quickly and with less filament usage.

The multiple labelled angles will allow you to create nearly any shape. If you have a PVC pipe bender, you can also create curved tops for your structures. The additional snap-on connectors provide an option to add extra supports later, so you don't have to feed conduit through the attachments again. This can assist with cross-bracing or if you feel the material is sagging at any point and want to shore it up. You can also use them as a hinge if you want to add an swing roof for harvesting vegetables.

*See image 6 in the model pictures

I have used this to create shade tunnels, small frost protectors, a rain-shelter lean-to for my garden tools, and a print enclosure, but you should be able to create pretty much anything you want. There is currently a 25mm and 30mm range in development for more robust requirements.