Personal Fabrication Update #2

I am still manufacturing Contraptor hardware, in order to bootstrap myself a RepRap.

I found a Canadian supplier of bearings (for the shaft mounts and linear bearings), and do I ever feel stupid because I knew of them all along.  Lee Valley sells sealed bearings for use as guides on router bits, and they stock the two sizes needed for Contraptor components (and 608s that would be useful for RepRap, however I already bought some skateboard bearings).  They also now carry more Starrett tools than before; I picked up a Starrett 819 automatic center punch (catalog #30N28.25,  I had been using a Veritas automatic punch with pegboard to manufacture perforated angle but it wasn’t up to the job of punching aluminum.

Here are some useful tips for building the hardware that the Contraptor folks either neglected to mention, or figured you already knew.  I’m telling you now because I did it the hard way first.  If you are using paper templates to lay out your cut lines and hole locations, glue it down with a glue stick.  I tried spray adhesive, but that was too slippery (and then a real pain to remove when it dried).  Place the paper on your angle with light pressure, adjust to proper position and then press down.  Leave it for a minute or two, and then it’s not moving at all.  There is also no need to remove the template before drilling.  In fact it’s easier to line things up (and you don’t get confused and drill the wrong size hole somewhere).  You also don’t need to remove the template before sawing (again, I thought I’d make a huge mess and lose where the next line would be).  Cutting the aluminum with a hacksaw is not such a pain (especially with a 32TPI blade and a good saw), I tried using my compound miter saw with a carbide blade, but the kerf is too thick so it throws off all the dimensioning (especially for templates).