The frame stands about 8" tall by 12" long. The short arm/ long arm ratio is what I was testing, and the different ratios are 2:1, 2.5:1, 3:1 and 3.5:1. In theory, when the counterweight is dropped, the projectile arm rotates and whips the sling around, … ONLY adjust the Release Angle, determine the optimum angle of release. tabletop trebuchet, and therefore to find which conditions are necessary for optimum range. The floating arm trebuchet uses rails to constrain the counterweight vertically and to allow the arm pivot to … First, the leverage ratio should be 2:1. A third type, the "traction trebuchet" does not have a counterweight, as such, on the short end. Trebuchet is Old French, from trebucher "to throw over" < tres "over, beyond" and buc "torso" < Latin trans and a Germanic word.. Trebuchets are often referred to as a variety of catapult, though this word is today generally reserved for a device powered by elastic energy.. Other names for counterweight (or … The trebuchet relies on the principle that stored potential energy of the counterweight can be converted into kinetic energy of the payload, launching it into the air. I found some good web pages with highly detailed answers to predicting the range of a trebuchet. For the original FAT the counterweight guide tower height is 70% of the arm length. Cut a rectangle of Thick Card (210mm x 100mm) and cut narrow strips (210mm x 25mm) to form the Chassis. That's a weight ratio of 1:110. Adam tinkers with his mini medieval weapon to show us.Did you miss the latest episode of MythBusters? A counterweight trebuchet is powered by a very heavy counterweight, acting on a lever arm. A trebuchet on a ship is entirely possible. While a counterweight trebuchet could toss a boulder over a castle wall, there were definitely trade-offs. Refresh the … For one, it took a really long time to reload the counterweight. The key benefit is that since trebuchet is a counterweight engine, it can be built to be powerful without shaking the ship apart when it is fired. This means that it isn't viable for height constrained competitions. That’s an example of a counterweight trebuchet, and is what the defenders of Minas Tirith used in the … The counterweight is about 3500 grams, with the projectile being 60 grams. Trebuchet: The payload is at one end of an arm that pivots in the middle. That's what a trebuchet is, a lever. To further analyse this phenomenon I have created another graph that keeps a constant counterweight mass and but changes the ratio. Hypothesis I anticipate that the greatest range of the trebuchet will be achieved when there is: A large ratio of counterweight mass to projectile mass – i.e. A typical beam ratio might be 5:1 MR Mass Ratio. Image by Ron L. Toms. Fixed counterweight designs tend to try an pull the treb over. Model Trebuchet can be made using Stripwood Technology techniques with card and 8mm x 8mm square timber. Finally, watch your trebuchet go. To begin, enter the parameters of your trebuchet in the input boxes on the left. What's the secret behind a perfect trebuchet? We were given a 2 kg counterweight, and the water filled ping-pong ball will weigh about 36 grams. Licensed under CC BY 3.0, via Wikimedia … A trebuchet works by using the energy of a falling (and hinged) counterweight to launch a projectile (the payload), using mechanical advantage to achieve a high launch speed. A fixed counterweight is simply a heavy weight on the end of the short arm. Construction of either is based on ratios. On one side of the beam, at a distance r1 from the fulcrum, is a counterweight … Keep in mind that the larger the ratio, the heaver the counterweight has to be in order to provide enough force to launch the projectile. Refresh the screen. Team # 210 – Page 3 Problem Definition Consider the trebuchet represented in Figure 1. The main beam and counterweight rotate upon sturdy steel shafts, providing years of service life. This is an f2k style floating arm trebuchet. I know that the ratio of the projectile arm length to the counterweight arm length changes depending on several factors, most importantly the ratio of the … The “physics rule of thumb” is to use a counterweight at least 30 times the weight of the missile. War Wolf was the largest trebuchet ever made and was rumored to send boulders of about 150 kilograms across a distance of over 200 meters. When the catch is released, the weight swings down and the end with the payload is hurled upward. That means I had a ratio of 1,500:1. I am working on creating a mid size trebuchet with a projectile arm length of 3 feet. Virtual Trebuchet 2.0. stone a distance of 900 ft. At the height of its power the trebuchet was an unstoppable force, crushing fortifications, buildings and men alike.. My son loves launching stuff with this thing, but he needs help loading it. This is the 5th iteration of the trebuchet SiegeWorkshop has developed to date, meaning you get years of design and testing right out of the box. A counterweight trebuchet’s arm and sling swing up to a vertical position, releasing its housed projectile at a ferocious speed and power. Fulton says that the smaller traction trebuchets could fire up to four shots a minute, while the biggest trebuchets were lucky to get off one shot every … A (heavier) weight is at the other end. Of course, the hanging CW trebuchet sacrifices counterweight fall distance for this efficiency. The wheel track length is just over 1/3 the arm length and is just under half the arm length in … the mass of the counterweight is far greater than the mass of projectile. Wheels are often used on trebuchet designs that use fixed counterweights to counter the tipping motion. The trebuchet's range could be adjusted simply by adding to or subtracting from the mass of the counterweight. A small-scale replica of War Wolf, a counterweight trebuchet that uses a boulder-holding sling at the end of a swinging arm. Etymology. Since the counterweight weighs in at 1lb, 6oz (on a postal scale), the ideal projectile seems to be a standard glass marble (lighter than I would have guessed, at .2oz). It consists of a beam of mass m2 which is pinned at the point O (the origin of the xyz-coordinate system, and henceforth referred to as the fulcrum) at some distance h0 above the ground. Also, the length of the CA in meters or feet. ONLY adjust the Mass of Weight, determine the optimum mass of the counterweight. The biggest and most powerful trebuchet ever made, Warwolf , stood over 4 stories tall, weighed 30 tons, had a throwing arm 50 ft. long with a 20 ton counterweight, and could hurl a 300 lb. However, an effective trebuchet would have a 100-1 ratio, he said. Trebuchets, large siege weapons common in the Middle Ages, are complicated dynamical systems. The mass of the counterweight is what makes things happen. VirtualTrebuchet is a web based trebuchet simulator that will allow you to quickly evaluate different trebuchet configurations. A fixed counterweight trebuchet may be equipped with wheels which will allow the entire engine to move first backwards and then forward as the counterweight end drops, which again allows a more nearly vertical drop. I'm still not … The setting: King Richard’s crusades in the latter half of the 12th Century. Set the mass of the counterweight to be 50 and the mass of the throwing arm to be 5. From here you can see the maximum deviation of the throwing arm on … I find a 10:1 ratio reasonable for the animation, though you may want to look up how it’s actually done in real life. Start by making a reinforced card base for a Rolling Chassis, 210mm long and 100mm wide : . The floating arm trebuchet is a counterweight siege weapon which is a modern variation of the medieval trebuchet.Their defining feature is free movement of an axle on the throwing arm, and a linear drop channel for the counterweight. I’d assume 100:1 or something would be more apt for a real trebuchet, but that will sort-of break Blender’s … General advice is that the optimal ratio is 133:1. Then, through research it was said that the most efficient ratio for the throwing arm is about 3.75:1 for the length of the arm on the launch side to the length of the arm on the counter weight … This is about a 55.6:1 ratio. Obviously, there’s a connection between the counterweight and the throwing arm/projectile. The counterweight should be 75 to 100 times the weight of the projectile. One of the most important components of the trebuchet is the sling, which greatly increases the range of the weapon by simply extending the length of the throwing … BR Beam Ratio. Each Trebuchet kit is hand built and tested by SiegeWorkshop, making your trebuchet … The design and construction of such machines is a popular project assignment in post … A golf ball projectile (1.62 oz) should fire best with 13.46 lbs of counterweight – and a 14 lb bowling ball should have 1862 lbs pulling on the other side of the arm to reach … One of these days I'll post a video of it. A diagram of the main parts of a trebuchet. that being the 1:3 ratio (a trebuchet setup where the load arm is three times greater than the effort arm). A stroboscopic shot of the trebuchet firing a blank shot. Explore the physics behind a counterweight trebuchet here. The throwing arm was configured for a 4:1 ratio between sling side and counterweight side respectively. Changing the length of the arm doesn't change the forces that the counterweight provides upon the projectile other than in the losses to the kinetic energy of the arm itself. At the peak of my trebuchet's existence I was using a counterweight of around 150 pounds, and the golf ball I was launching weighs 1.6 ounces. The rest of the frame is based on the length of the arm. A very simple model we have used in my Intro to Eng class just uses the mass of the projectile (m2), the mass of the counter weight (m1), and the height the counter weight falls (h): Range (max) = 2 * (m1/m2) * h Now the efficiency of the trebuchet … For maximum launch speed the counterweight must be much heavier than the payload, since this means that it will "fall" quickly. The downside is that since it is a counterweight engine, it introduces large moving masses to something already unstable. I won't tell you which one was the best yet, although you can probably guess. In general, a 100:1 counterweight to projectile ratio is adequate. The proper ratio for the throwing arm to the short arm is approximately 4 to 1, while the proper ratio for the counterweight to the projectile is approximately 100 to 1 [4]. Figure 2. The ratio of the length of the TA to the length of the CA, expressed as TA:CA. It can easily launch … For office wars it can be adjusted to launch objects high over cubicle walls and vanquish your opponents. The graph displays the range of projectile as the y-axis and the ratio as the x-axis. A good length ratio to use for a trebuchet is either 4:1 or 5:1. Indeed, counterweight is key, he says. ; Hold strips … Next, press the submit button located under the inputs. Counterweight Arm - That part of the beam from the main axle (or fulcrum) to the release pin. Here are several modern designs that you should look into. The counterweight is about 36 pounds, but the big, wide wood piece (the short arm) was probably around 20 lbs. That means that the long part of the arm is either 4 or 5 times longer than the short arm with the counterweight. The arm is 7 feet. It's the ratio of the short arm to the long arm that determines the mechanical advantage of a lever. To learn more about trebuchet physics, launch Virtual Trebuchet to learn techniques to increase trebuchet launch distance. × Warning Your internet explorer is in compatibility mode and may not be displaying the website correctly.