Oh, I forgot to mention that there are two YouTube tutorials on making the large and small steel rod slingshots, which relate to the written version:
A note on changing bent rod slingshots
, whether purchased or homemade; changing the length of slingshot forks will shift the load factor in the overall structure, and bending a specific section in another direction that was already bent will weaken the metal bonding at that point.
Many commercially available steel rod slingshots are made of 6 mm thick steel, so this is all the more important. Only work on steel or aluminum rod in good condition i.e. no corrosion.
All bending of metal rods should always be fairly gradual, regardless of whether you're making a new slingshot, or modifying an old one. This will also help significantly to achieve the correct angles sought. Bending in the opposite direction to correct angle errors of the initial bend will weaken the metal.
: In any case, be sure to test any modified steel rod slingshots by subjecting the forks to a "stress test"
, i.e. attach some paracord (app. 0.31 inch thick) to the forks with the slingshot secured in a vice (if possible), and pull very hard. If anything is weak, you will find out.
Moreover, regular steel (high carbon content) will bend gradually under stress, and should generally not snap suddenly. Stainless steel contains roughly 18% chrome, which makes it very corrosion resistant but also increases overall rigidity: thus, there will be less of a warning if something in the metal bonding is weak following repeated bending in the same section. That said, the forces applied by an average set of flat band or tubes are well below the maximum load limits of a 6 or 8 mm steel rod slingshot.
Be very careful with aluminum rod, though: it comes in different compositions, and can break under stress without much warning. :hmm: Bend it very slowly when making slingshot frames.
Also bear in mind that some of the bends on commercially available steel rod slingshots are fairly complex: 3 dimensional sahpes are not unusual.. A regular rod bender can of course be used to go beyond the 2 dimensional shapes, but it takes some serious effort: I did this using 6 mm aluminum rod while looking into fork hit protection methods (photo attached).
Least but not last, I read up in detail about the properties of all the materials (metal and wood) I wanted to use, because I had never done any of this either before I started one day. Safety is always on top of my list.