How often have you wanted a simple part but it just didn't exist. I'm thinking of the clutch push rod seal retainer for a CB160. It has to be big enough to hold the seal in but small enough to clear the sprocket. The first thought is for a nice lathe to cut the piece from aluminum stock. Hmmm. I seem to be short on lathes and metal stock at the moment.
Plan B: go to the hardware store and get some PVC pipe and cut it to length and put a couple of big washers on either end to hold the seal. Cheesy and about as elegant as a donkey on roller skates in the Easter Parade.
Enter the MakerBot, billed as the "Robot that Makes Things".This 3-D printer can construct just about anything using the same sort of plastic as Legos use. It can even construct a hollow sphere!
Just the thing for my seal retainer and once I make one I can make a million just like it for all the other racers. $1000 may seem steep for something you might only use once in a while but I'll bet that if you had it you would be thinking of all sorts of things that need making.
A constant problem for vintage restorations is parts that are no longer available. Unobtanium! However, there is usually somebody that has one but doesn't want to sell it or the price is too high. If only you could clone it!
Enter the 3-D scanner. As Jay Leno demostrates, a few minutes and you can have all the details in a working file. Feed that to the MakeBot and you have your part. Admittedly, it won't work for a cylinder head or transmission gear but maybe a side cover or tail light bracket? Use your imagination!