I wanted to make a REALLY powerful slingshot crossbow. But of course there is only so much draw weight you can handle, and even the push-out forks have their limits. So I had to incorporate a winch.
So I used an entirely new concept. The entire trigger/lock part slides between two 40mmx20mm wooden rails. The winch rolls up a mountaineer type rope wich draws out the band. A rubber powered arm locks the winch every 45 degrees of turning (8 positions on a full turn) Trigger and lock have aluminum tubes glued into the wood so the force is evenly distributed and the screws do not wear out the wood.
The force vector of this slingshot is entirely straight, there is NO fork height at all. This makes the weapon incredibly strong.
I had little time to shoot it as it is dark, but it has a ton of power with the first test bands (20cm x 14cm x 7cm Thera Gold per side). A child can operate the winch, and there is much potential for even stronger bands.
A fantastic new weapon, brought to you by The Slingshot Channel!
This video uses a great piece of equipment for learning more about rubber bands: A thermal camera! This professional product made by Jenoptics has a resolution of 360×240, means, more than 86,000 laser thermoscopes are building an image. Much like the “heat visor” the predators use in the movies!
This way, heat structures can be made visible. It is mostly used to check how well a house is insulated, but it is also fantastic for scientific experiments.
Here, the thermal aspect of slingshot rubber is researched with the camera. It turns out that rubber bands store the muscle energy the shooter invests by drawing out into thermal energy – the bands warm up very quickly. When the shot falls, the bands retract and then they get very cold, intstantaneously.
The video clearly proves the fact that a long pause for aiming lowers the speed of the shot dramatically – because the drawn out bands loose heat, and therefore energy.
Last not least, a lead ball is fired three times against a rock – and it gets about 20 centrigrade warmer because of the deforming.
Ballistic Gelatine is a certified material to test the impact of bullets and other projectiles. The material simulates flesh. Three different home-made slingshots and four different types of ammo are used against a 3 kg block of gelatine. The impact is recorded with a camcorder that records 1200 frames per second (super slow motion), so it is possible to watch the impressive and devastating hits in detail.
Dramatic High Speed scenes of slingshot action. Watch heavy steel balls shattering bottles and smashing oranges at 300, 600 and 1200 frames per second. This is must-have-seen stuff for every slingshot enthusiast. The casio EX-F1 Pro camera was used for the high speed shots.
his video is one more experiment in order to find out the truth about how rubber works. We know now that bands warm up when drawn out and cool down when released. We also know that when the drawn out bands cool down to room temperature, they loose a bit of their power. Heating up those bands brings all of the lost power back.
This pretty much supports the “Entropy” model. When you draw out a rubber band, you bring order into chaos, and this generates heat. When you let the bands swing back to chaos, this heat is lost (converted into kinetic energy).
But there was one thing that was missing: What happens if the bands are getting very cold? This was tested today in this video. Bands were drawn out and left out in the cold, until they reached about minus 6 centigrade. They loose all of their stretchiness! Funny wrinkles appear instead.
Drawing the bands out and letting them snap brings the stretchiness back.
Also, a new slingshot is presented, this time with the rubber bands wrapped around a Zippo handwarmer…
A “The Slingshot Channel” production.
On December 30th, 2010, The Slingshot Channel presented a functional “desktop size” slingshot cannon. It fires 8 mm steel balls.
Finally, the model was turned into reality! 10 times bigger than the model, it fires 80 mm steel balls now… with impressive force.
The huge amount of rubber (6 full Thera Band Gold stripes per side, 72 times stronger than “hunterbands” for conventional slingshots) propels a steel boule/petanque ball fast enough so it flies 200 meters (220 yards).
See how it smashes beer barrels and even a car… lots of slow motion is included.
The winch allows insane draw weights. Here, more than 200 kg was employed. In combination with the “barrel length” of 3 meters (10 ft), it achieves firearm like energy levels and the momentum of a giant sledge hammer.
This may be the strongest rubber based weapon presented on youtube ever.!
A “The Slingshot Channel” production.