This is the place for all the small designs that are have a unique purpose of opportunity, which means an object that was made only once for a specific purpose.
Burr Puzzles are traditionally made of wood, but I made one that can be printed by a Cupcake. There are six pieces altogether with about a little more than a dollars worth of material. The puzzle is design for a perfect fit. If you want to make it more loose then you can modify the stl files for each piece. This particular puzzle takes fifteen steps to put together so it is quite fun. However, trying to figure out how take it apart is as much fun.
To put the puzzle together refer to this web page: research.ibm.com/BurrPuzzles/Samples.html
You can download the STL flies here.
I made this bike mount at my good friend's request. The mount is
fairly heavy duty. The estimated cost is $0.80 of ABS material at $0.02
per cc. I printed it with a honey comb structure making it strong for
vertical compression. As a tip, I recommend coating the mount with
epoxy for easy clean up and then paint it with a "Sharpie". Enjoy.
Print the only two pieces and then use two bolts and two hex nuts to mount on the bike rack. I used wide cap bolts [50 x 5.5mm or (2 x 0.25 in)]. I added extra diameter space for the bolts so if you find anything close to that you are fine.
You can download the STL files here