Slingshots?

[KB291]

In early 50's my brother and I and one of the neighbor kids would take cherry bombs, pack wet clay around them and let it dry. With a modified pouch, as in oversize, one of us would draw back and the other would light the fuse. Played hob with the squirrels. Timing was VERY critical.

[Bret4207]

Where I used to live my neighor had a miniture stud horse. Nasty little bas****. Of course her idea of fencing was rather liberal, as was her idea of "clean". So when one of my mares would go into heat he would be in my yard constantly. Got so I could hit the little pr...., I mean fellow on the run on a regular basis with my Wrist Rocket and 44 cal balls. The final straw was when the stud ran a horse we were boarding through a fence and cut her up. The lady next door and I had a very loud, one sided conversation. The stud horse left shortly thereafter. I always liked the Wrist Rockets, which BTW are illegal in NY state. Rumour has it gang members were using them. They are still for sale oddly enough. The rubbers rot and I replace them with heavy gauge surgical tubing fron Brownells. I got so I could hit pine cones or individual maple leaves at 50 feet or so, which I felt was good. I'll have to find mine as I haven't seen it since my son "borrowed" it.

[waksupi]

Brett, that reminds me of a friend who passed away a few years ago. On his place, the bighorn sheep would come down and winter on his place. He had fruit trees in his front yard, and the rams would rub thier horns on them, killing some. He finally got fed up with them, and got out his bow and arrows. He put one of the big rubber blunt tips on and arrow, and waited on the front porch until one started rubbing again.
His intention was to hit it in the ass or the ribs, which ever presented itself. As things were, he had a rear end shot.
He drew back, and let fly. And hit it square in the scrotum, from a 65 pound bow.
He said it dropped like a rock, and lay there quivering (I would have too!). He was afraid he had killed it somehow, and was somewhat panicked, as it was right along the highway, and he didn't want a F&G guy coming along finding a dead trophy ram in his front yard.
He was ready to drag it around the side of the house out of sight of the road, when he saw a rear leg kick. Then a couple more kicks. And finally struggled to it's feet.
He said all this didn't seem to bother any of the other bighorns in the vicinity, but he had definitely got this ones' attention, and didn't catch that one rubbing any more cherry trees.

[imashooter2]

In early 50's my brother and I and one of the neighbor kids would take cherry bombs, pack wet clay around them and let it dry. With a modified pouch, as in oversize, one of us would draw back and the other would light the fuse. Played hob with the squirrels. Timing was VERY critical.

"Here, hold my beer and watch this!"

[shooter575]

BiS
Allways thought a siege crossbow using a leaf spring off a truck and steel cable would be fun.Need a come a long to cock the thing. 1/2 or 5/8 re-bar for bolts. 16 ga for fletches. Only thing that scared me is the cable breaking.Would cut a man in half.

[wills]

There used to be a writer named Daniel P Mannix who wrote for True magazine back in the 60’s (and for all I know others). One of his articles dealt with building old siege engines and if I recall correctly he did in fact build a crossbow with truck springs and cable. I think his bolt was pretty big, something like a crowbar.

[Bigscot]

Bret,
What size tubing did you get from Brownells? I may have to order some. Did you just tie it to the pouch?

Bigscot

[carpetman]

Bigscot--Surgical tubing can be obtained at hospital supply houses,many pharmacies also have it. Wrist rockets use the tubing. For slingshots that use the flat stuff,you can go to an office supply and buy big rubber bands. Commercial made ones have connectors that the tubing slides over to attach things. If you don't have connectors, fold it over and tie it down with fishing line.

[Ballistics in Scotland]

Aha!!!! Here is an eBay auction for harpoon gun rubber tubing, which should be better than surgical:

http://cgi.ebay.com/ws/eBayISAPI.dll...&rd=1&tc=photo

We don't have a rule against promoting auctions, I trust? Very sensible, for in this field they often represent information which others would like to have while it's usable. I'd guess that this seller auctions the same things regularly, though. The way to secure it would be to squeeze in the largest waisted plug that will enter, then apply a very tight binding of yachtsman's nylon whipping thread, or someone's kevlar, and lacquer it with epoxy or superglue.

The classic book on building early crossbows and catapults is Sir Ralph Payne-Gallwey's "The Crossbow", and www,bookfinder.com is packed with inexpensive reprints. There is nothing like a good hobby to keep a man out of mischief.

The speed at which a crossbow (or, I think, slingshot) will accelerate a projectile, isn't in perfect proportion to its power, or in perfect inversion to projectile weight. A steel bow, for example, will only reach a certain speed, no matter how light the projectile is. Glass or carbon fibre will be faster, and I think this is partly because of their elasticity, as well as the reduced weight of the bow, which is itself a non-productive part of the load. In practice a weight of bolt will be found which gives the optimum velocity and energy with a given bow, and departing from it in either direction will reduce the performance. I think only a really enormous steel-bow crossbow MIGHT be best with solid steel bolts (and if I thought so, I would use smooth rod, not rebar, and cover them with electrician's heat-shrink tubing to prevent damage to the guides.) For most crossbows wood or aluminium tubing, with a steel point, is about right. If you find you can get more penetration and no serious trajectory loss with more weight, a lead slug inside the tube behind the point is probably the way to do it. This weight distribution would enable you to trim the flights of the bolt slightly, reducing air friction.

The bow breaking is indeed an intimidating prospect. I had a fibreglass crosshow long ago, which broke, perhaps due to use in very cold weather, and that was a very reassuring greenstick fracture. This might not be the case with carbon, and certainly not with steel. A British seller on eBay offers kevlar braided sleeve, which could be used as a sort of unlaminated sock for safety.

http://cgi.ebay.com/ws/eBayISAPI.dll...&rd=1&tc=photo

The trouble with trucksprings is that the two limbs would have to be made exactly identical in thickness, curvature and temper, since a scraping of the string across the rear of the bolt would be very bad for accuracy. If you add the fact that it should be a concave rather than straight taper, to give strength close to the point of maximum stress near the centre, it is an intimidating grinding or forging job. I often look at my massive belt grinding machine, but it is a far bigger job than an octagonal barrel. I would sooner laminate one, using a number of thicknesses of glass or carbon cloth which reduces towards the tips. I would make the curve by a saw-cut through a large length of wood. One half would be used as a mould, and the other clamped on to squeeze out all but the irreducible minimum of resin.

For a rubber-powered device, there is an interesting effect from the distance apart the fixed ends of the rubbers are. In a slingshot, the distance the rubbers can move the projectile is equal to the amount they are stretched. But if the attachments are further apart, like a sort of non-bendable crossbow, the stretch is several times the projectil movement. This gives a mechanical advantage, like gears, and should be better with a heavy projectile.

If we could find a way of launching a 16g. lead ball at archery velocities or greater (why not?), we have an instrument that could do things. In British law we would have the interesting situation that it isn't a firearm (which needs a barrel and lethality, though not necessarily combustion). It is therefore subject to no controls whatever on construction or possession, although carrying it is public is contentious. It might even scrape through our prohibition on using a crossbow to hunt any living thing, though that would need a lot of checking. Oblige me by think about a 4g. for a couple of minutes...

[wills]

Bigscot--Surgical tubing can be obtained at hospital supply houses,many pharmacies also have it. Wrist rockets use the tubing. For slingshots that use the flat stuff,you can go to an office supply and buy big rubber bands. Commercial made ones have connectors that the tubing slides over to attach things. If you don't have connectors, fold it over and tie it down with fishing line.

Academy, a big box sporting goods store has the replacement elastic tubing complete with the pouch for $1.99, so it is probably available other places too.

[longhorn]

Auto supply stores are a dependable source for rubber tubing. I use almond M&M,s for biodegradable ammo for discouraging roaming varmints at relatively close range. Of course, you have to sort for the best aerodynamic capabilities; personally, I eat the rejects.

[45nut]

That is the responsible thing to do Longhorn.. Personally I prefer the Peanut M&Ms and find only the red ones accurate,that leaves many of the unsuitable ammo colors completely suitable for immediate consumption.

[HTRN]

Let's see.... My brother put a water balloon through my Mom's front window from a block away when we were kids using one of those water balloon slingshots...

You want a fun project? Build a mega slingshot. Next time you change garage door springs, save the old springs, and get yerself a large funnel. Drill two holes 180 degrees apart and attach one end of each spring into one of the holes.. See where I'm going with this?

If you get caught doing something stupid with it...


HTRN