3D Model

    Another of my unfinished projects is my miniature brass cannon.  The idea was to build the world's smallest working cannon.  According to the Guinness Book of Records, the smallest firing cannon is 1.25" long.  I immediately set to work in Inventor modeling cannons, and designed a fully functional cannon with a total length of .75"  After rigorous stress testing, I began building 3:1 prototypes.

    The 3:1 model utilizes a .117 caliber bore.  Boring tools and ammunition are readily available for this size, making it affordable and easier to manufacture than the final 1:1 cannon.  To keep costs down, the barrel is shaped by hand, and a makeshift temporary carriage is used for the prototype.

    After cutting and polishing the bore, I shaped the barrel with a home-made lathe and rigged up a carriage from oak and aluminum for testing.  After making a few small adjustments to the design, the first prototype was ready to fire.

The first few prototypes at 3:1 scale

3:1 scale prototype.  Bic for size referenc

   I bought some M-1000 firecrackers to harvest my wicks and black powder from.  However, as it turns out, modern firecrackers contain a combination of aluminum powder and potassium perchlorate known as flash powder, not black powder.  While the black powder is mixed uniformly and very easy to work with, the flash powder's ingredients have to be kept separate from one another in very precise quantities in order to work.  This makes loading the charge into the cannon a daunting task.

    After numerous "blind" attempts at packing a charge, I did some quick calculations and came up with a rough ratio of aluminum powder to potassium perchlorate, and finally was able to fire some wadding.  It now sits, all but forgotten, awaiting some true black powder.