Snap Assembly Tarp Grommet... The idea is to provide a snap install grommet. Chamfers have been added to make edges friendly to the tarp at the periphery of the flanges. A hole must be cut or punched in the tarp to accommodate this grommet. I haven't tried changing the variables much to see if everything else falls in line so do some quality control testing if you need to alter size. It should be close though.

In the photograph I have demonstrated by making a couple picture postcards a lot stronger if one were to run a rope through them, mirror shows backside.

It's a tight snap fit and either strong hands or a pliers will be needed to consummate the installation. The flange separation is 1 mm as the .stl sits so one should be able to do a double layer of the cheap tarps.

It was developed in OpenSCAD, a code driven modeler that is parametric. This enables interested users to customize.

I and two other coaches are FTC mentors for two teams and hope you see merit in the idea. It would be a great boon to our children!