To make a Square Target In the Style of Marozzo or DiGrassi
I wanted a shield that would be the maximum legal size for Gulf War (453 square inches.) According to the marshallate, for a wavy shield, what is measured is the final size--the footprint, if you will-- not necessarily its total surface area.
I started with a large piece of heavy leather (about 12 ounce) from Tandy and some 3/4-inch bar stock from Home Depot. First I cut the bar stock into four pieces with a hacksaw, two bars 20.5 inches long, and two at 19 inches. Next I drilled a series of holes about 2.5 inches apart along the length of all four pieces, starting about 1/2 inch from the ends. Then, using a vise, an anvil and a hammer, I bent the 19-inch pieces into a curving W shape, to get the wavy effect. (Fig. 1) When finished, the curves were about 2.75 inches deep, and the bar from end to end was about 14 inches. Ideally the curved pieces should be identical, but if they're a little off, that's not a major problem.
Next, I attached the two 20.5-inch pieces to the curved pieces to make a rectangular frame. (Fig. 2) (Note: I used rivets for most of this project, because I have a bunch of them. You could use small nuts and bolts instead, just be sure the bolts are fairly short so they aren't sticking out too far on the inside of the target.)
Once the frame was built, I cut the leather into a rectangle measuring 23.5 inches high and 21 inches wide. This allowed it to overlap the metal frame by about an inch on all four sides, so there is very little chance of the corners of the frame actually hitting someone. I soaked the leather thoroughly in water to make it soft and pliable, then started mounting it to the frame. (If you've never worked with leather, soaking it in this fashion makes it easy to form, and when it dries it will stay in the new shape.) Starting about an inch in from the edge of the leather and using the holes along one of the straight metal bars as guides, I drilled matching holes in the leather and riveted them together. (Fig. 3)
Next I started attaching the leather to the curved pieces. To make sure the leather stayed flush with the frame, I drilled and riveted one hole at a time and alternated between the top curved piece and the bottom one. (Fig. 4) When both curves were done, (fig. 5) I drilled and riveted the leather to the remaining straight side.
When I first built this target, I designed it to hang off my arm, like a typical armored combat shield. While this provided adequate body protection, I soon discovered that it wasn't anywhere near as mobile as I would like, so I took off the arm-mounting and built a center-grip instead. I am much happier with this design. The grip I use cannibalized the leather from the forearm strap. I cut it lengthwise into two pieces, soaked them to make them pliable and built a sort of twisted X-shape for the grip. (I was in a hurry and those were the materials immediately to hand.) This is the only part that is bolted instead of riveted. Alternatively you could build an I-shaped grip with some of the leftover pieces of 3/4-inch bar stock and a piece of wooden dowel and mount that in the center of the target. (Fig. 5)
This target is fairly light (about 2 lbs) but quite sturdy. In practice, I've found that DiGrassi's suggested position of holding it at arm's length with the upper left corner highest and cocked slightly toward the opponent is quite practical. Incoming shots will either stop in one of the "valleys" or slide down and away to my left.
The finished size is 17 by 23.5 inches, which gives a footprint of 399.5 square inches. That's actually a bit smaller than the maximum size for Gulf War, but I'm happy with it. If I wanted to make the target wider it would be fairly easy to do so by flattening out the curved bars a bit. 23.5 by 19 inches would be the maximum legal size for this particular configuration.