Tramp Clamp
A shim or clamp or something for my trampoline to allow the safety net pipe to bolt to the frame pipe. One broke and so I needed another. This should really be a parametric design with configurable radius on both sides, etc. It may be my first project on openscad whenever I get around to installing and fiddling with it. Currently one side is for a 1+1/4 inch pipe and the other side is for a 1+1/2 inch pipe.
It doesn't have a hole for the bolt because sketchup is terrible at doing holes through curved surfaces. It's quick and dirty. 1/2 hour from concept to installation, and the thingiverse entry was done while the part was printing. :)
I think it would have taken more time to find an online retailer willing to sell me a part like this if there even exists such a store, and then to pay $5 for shipping and $5 for a 30 cent plastic part seems silly. There, now I have justified 1% of my Makerbot purchase.
***Update: I have now crossed the line into openscad geekiness. The parametric version of this part is http://www.thingiverse.com/thing:11263. Now a more generalized pipe clamp is available for the unwashed masses.