Floating Arm Trebuchet. [9] These machines and their designers are frequently to be found competing in various recreational events, for example, pumpkin chucking contests. The washers and nuts will be assembled onto the bolt in the order shown. The illustration above gives a diagram of a “floating-arm” trebuchet. Cut and sand the frame pieces and swing arm. The longer the ratio, the greater the speed that tip of the throwing arm will reach – but also increasing the force required to move it quickly. Floating arm Trebuchet. 14 150 1. [2] The projectile can be launched at a high velocity.[7]. Make sure the glide rails do not intersect the drop channel at all. This variation features a drop channel, which allows the counterweight to fall straight down rather than swing with the arm. There’s no “best” angle—it depends on what kind of trajectory you want to achieve. Create the drop channel: Hot glue four square dowels upright at the center of the base. The pins should fit in the holes loosely. New machines have been constructed and old ones restored by living history enthusiasts, for historical re-enactments, and use in other historical celebrations. The main difference is that rather than having an axle fixed to the frame, the axle is mounted on wheels that roll on a track parallel to the ground. Reviewed in the United States on November 24, 2012. This design is more complicated to build than a traditional trebuchet, however the launching mechanism is more effective and much more gratifying to behold! The floating arm trebuchet is a counterweight siege weapon which is a modern variation of the medieval trebuchet. The counterweight hits the glide rails while falling down. [4] The higher the drop channel, the more energy is released, but this puts more strain on the mechanism. Friction when the counterweight is dropping down to the glide strike can be reduced by using silicone grease or a thin film of plastic on the drop channel. This is a more efficient way to transfer potential energy into kinetic energy at a small scale. A Floating Arm Trebuchet or F.A.T. [2] The eye bolts are usually placed at the bottom of the frame, locking above the arm to prevent accidental release. Please message me to report broken links. Source(s): floating arm trebuchet calculator: https://biturl.im/qmt91. Use the 5" (12.5 cm) pieces of paint stirrer and the four 6" (15 cm) square dowel pieces to form the glide rails. The trebuchet derives from the ancient sling. How wide were your paint stirrers? Reply Make the drop channel gap slightly wider. Loop the string onto the paperclip and place the projectile onto the base. One of the first pieces to consider is the ratio of the short arm to the throwing arm. Use the 2" (5 cm) pieces of paint stirrer to add structural support to the glide rails and to help maintain a uniform gap. [2] This causes the wheel on the axle of the arm to impact the glide track,[2][8] which is usually held steady with strong support beams. Welcome to the original version of VirtualTrebuchet! This mini version of our World Famous Floating Arm Trebuchet is a real powerhouse in a desktop sized package. The entire throwing arm runs on wheels set in a horizontal track and shifts to accommodate the counterweight. Virtual Trebuchet 2.0. The hole nearest the end of the arm maximizes the speed of the projectile, but it may not perform as well with heavier projectiles. To begin, enter the parameters of your trebuchet in the input boxes on the left. T Er base Floating arm trebuchet (Floating arm trebuchet) F 12in catapult project dimensions and requirements design history The first use of trebuchets was traced back to China in 4th century B.C. The space between the dowel pairs across the base is 1 1/2" (4 cm). He has taught in the mechanical engineering department at … Hinged counterweight trebuchet Opportunities With this new advancement the trebuchet reached the peak of its destructive potential, described in many texts only as big, great, huge or frightful machines. Reposition the drop channel beams further apart. Snugly fit 5 washers onto each end of the dowel. [2] The arm then jerks forward and releases the projectile from the sling. The floating arm trebuchet loses the range advantage over regular trebuchet at very large scales, because the difficulty in construction of the drop channel and axle increases with size. This is a more efficient way to transfer potential en… The Floating Arm Trebuchet Thanks for sharing! This linear drop of the counterweight is more efficient in transferring potential energy to kinetic energy than the pendulum counterweight motion of a traditional trebuchet. In general (e.g. What did I do wrong? The floating-arm trebuchet, a modern variation of a medieval weapon, is a popular project for physics and engineering instructors. A loop at the end of the string allows the projectile to attach to the paperclip. The design and construction of such machines is a popular project assignment in post-secondary engineering classes. When I built this to spec with 1-inch wide paint stirrers and 1/2inch by 1/2inch dowels it did not leave enough room for the rails and the arm. for the floating-arm trebuchet), we may have a set of constraint equations, instead of just one . View Team 1 - Floating Arm Trebuchet Engineering Report.docx from SCIENCE N/A at Crestview High School. The arm of the trebuchet is like an off-center see-saw with a huge counterweight on the short end and a sling attachment on the long end. MAKE THE FINGER. by Eric Schneider. You’ll need all the hex nuts and all but 10 of the washers. Finally, watch your trebuchet go. This trebuchet uses a floating arm rather than a fixed arm. [5] A projectile is loaded into a sling at the end of the throwing arm. The design and construction of such machines is a popular project assignment in post-secondary engineering classes. You can find the lesson plan, 1-page project sheet, and more project ideas at STEM-Inventions.com. The angle of the bend in the paperclip will determine the timing of the projectile’s release. Their defining feature is free movement of an axle on the throwing arm,[2] and a linear drop channel for the counterweight. Feb 2, 2014 - Floating Arm Trebuchet Plans Download - Page 2 Views of the Trebuchet Drill 1 inch (2.5 cm) holes into the top of the support arms. Next, press the submit button located under the inputs. A straighter paperclip will result in a quicker release and a higher trajectory. If you want more information on how a floating arm trebuchet works, there are plenty of videos on the internet. Drill four 1/4" (6 mm) holes into a square dowel. Did you make this project? When the trebuchet shot, the arm would start to throw the shot put, and when the angle was correct, the third pin was released from the nail. May23 by ethanahern. The invention of the trebuchet derives, no doubt, from the ancient sling. It can hurl anything from marbles to golf balls across the room or across the yard! =/- - ⋮-1 2=3 (20) but for the present, let us assume that we have only one constraint equation. I want to apologize for not having very many pictures of the building process, but I … Set the trigger by raising the counterweight above the holes and inserting the pins. Is it possible to make it so you can just attach a weight to the end? To reset the device, the counterweight must be raised back to the original height and locked in with the trigger mechanism. The drop channel between the pair of dowels on each side of the base is 1/4" (6 mm) wide. VirtualTrebuchet is a web based trebuchet simulator that will allow you to quickly evaluate different trebuchet configurations. A traditional trebuchet, which is simple to engineer, consists of an arm resting off-centre on an axle with a hinged counterweight at the short end of the arm. This project requires precision to work consistently. 5.0 out of 5 stars Mini Floating Arm Trebuchet Kit. This will be the roller that travels over the glide rails. Therefore, use only woodcraft that is perfectly straight and well-formed. [2] This pulls the counterweight upwards slightly after a launch. hey this is really cool... but i was wondering instead of using square dowels could you use the old square disposable chopsticks (like the ones you get in Chinese restaurants)? The floating arm trebuchet is a counterweight siege weapon which is a modern variation of the medieval trebuchet. 4 years ago. Give the trigger a swift tug to release the pins! Counterweights could be the size of a peasant’s hut, weighing tens of Glue the split paint stirrer pieces at an angle to support the glide rails and drop channel. One hole should be near the end of the dowel, and the other three are spaced 1" (2.5 cm) apart, starting 2" (5 cm) from the first hole. Check out my work: www.stem-inventions.com/, seven 12" (30.5 cm) square dowels, 1/2" (1.3 cm) wide, Cut two 12" (30.5 cm) paint stirrer into four 6" (15 cm) pieces, Split two of the 6" (15 cm) pieces down the middle, Cut the bottom of the split pieces at approximately a 45° angle, Cut 2 paint stirrers into four 5" (12.5 cm) pieces, leaving two 2" (5 cm) pieces. The glide rails do not cross into the drop channel. This evolved into the traction trebuchet in which a number of people pulled on ropes attached to the short arm of a lever that … :p. I've never seen this "floating arm" style of trebuchet before. While the floating arm design can have a lighter frame than a traditional trebuchet because the overall forces produces are less,[5] the impact of the arm on the glide track will cause eventual damage and may need maintenance. The tops of these pieces have been trimmed for a cleaner look. While this is happening, the wheel is moved backwards by the torque acting on the arm from the counterweight. The simulation itself has an efficiancy of 91%. Upon releasing the trigger, the counterweight is allowed to drop through the channel. Reducing the drop distance of the wheel axle to the glide track would reduce damage, but also reduce the range of the trebuchet. Center and hot glue the ends of the long pieces to the shorter cross pieces. A paperclip with greater curve will give a delayed release and a straighter trajectory. I would visit Ron Toms's site, he's the inventor of this type of trebuchet. Give it a quick test by pulling the arm back and letting it go. The floating arm trebuchet uses a counterweight held on top of a tall drop channel to transfer potential energy into kinetic energy. This is the simulation we used as base model for our Floating arm trebuchet. Get started with small but dense items. 5 years ago. Throws a six gram wooden ball with amazing force, easily over forty feet with 200 grams of counterweight. Create the trigger by tying one 30" (76 cm) piece of string to two 2" (5 cm) pieces of bamboo skewer. To reduce friction of the sling on the launch track, the track should have a smooth surface.[6]. [6] Friction of the wheel on the arm axle against the glide track should be managed in a similar way. Here are my troubleshooting tips that I discovered while tinkering and developing this project plan: The axles for the glide wheels bumps into the drop channel beams. The string length will also affect how far your projectile will launch. The floating arm trebuchet is a counterweight siege weapon which is a modern variation[1] of the medieval trebuchet. Stand to the side of the trebuchet to avoid being struck by a wayward projectile. The release mechanism is a hook with a specific bend in its tip to determine when centripetal force will release one end of the sling, freeing the projectile to continue on its path. 2. As mentioned, the angle of the paperclip is a key variable, as well as the type of projectile, and the length of string that it’s attached to. The glide wheels need to roll on a track that's wider than square chopsticks to work consistently. on Step 3. Verified Purchase. The machine has two rails raised in the air by a frame, usually wooden, anywhere from 6-10 feet (any height can be used, but the biggest I've seen are between 6 and 10 ft.). Virtual Trebuchet is a free web based trebuchet simulator. Looks like a lot of fun ! If the washers start falling off, rub a little bit of hot glue on the outside of the axle and the washer to keep them in place. Experiment with a variety of items to find which one will go the farthest. The goal is to use the weight of the counterweight (rather than friction) to hold the pins in place. Make sure the throwing arm rests between the glide rails before launch as shown in the image above. The sling or pouch, which contributes to acceleration of the projectile and then releases it at the desired launch angle, is often made using polyester rope or other durable thin material. In the summer of 2019 my supervisor at Waters Corporation approached me to ask if I wanted to join a fundraiser that my coworkers did each year for Community Harvest Project. Generalization to m constraint equations is straightforward, … General wisdom has a 5:1 ratio being the norm for a standard trebuchet, although 4:1 is sometimes used. [10][11][12], "Illinois Institute of Technology students build catapults to toss pumpkins", "Pumpkin Festival aims to be bigger and better", https://en.wikipedia.org/w/index.php?title=Floating_arm_trebuchet&oldid=1016180443, Creative Commons Attribution-ShareAlike License, This page was last edited on 5 April 2021, at 20:20. This project requires precise measurements to work consistently. A variation of the sling, called staff sling (Latin: fustibalus), contained a short piece of wood to extend the arm and provide greater leverage. The rollers in the arm can be positioned into different holes, thus altering the position of the fulcrum. For an indoor trebuchet, you can use 1 x 6-inch (2.5 x … The Floating Arm Trebuchet: The floating arm trebuchet is a modern take on an ancient war machine. The trebuchet is essentially a gravity powered energy conversion machine, turning potential energy into kinetic energy and using it to throw a ball. Straighten out a paperclip and then fold it in half. I never knew you could make a trebuchet like that. I just subscribed because I like that you have so many mechanical contraption based Instructables. The arm is on a moving axle and the torque acts on the entire structure, preventing stalling. This arrangement worked great for … Question Large scale designs require special trigger mechanisms that can hold the weight of the throwing arm. Get ready to assemble the counterweight and trebuchet arm. A pair of wheels allows the arm to roll along glide rails as the counterweight falls. In this high-efficiency design, the counterweight is constrained by a track to fall straight down. In contrast, a floating arm trebuchet features an axle on the arm freely moving along a horizontal glide track. The next step would be for it to be foldable/portable.Nice job ! Their defining feature is free movement of an axle on the throwing arm, and a linear drop channel for the counterweight. Runner Up in the Make it Move Contest 2016. [2] This allows for a higher drop height for the counterweight,[2] which is allowed to fall down a sturdy linear vertical "drop channel". The floating arm trebuchet is a modern take on an ancient war machine. Set the counterweighted arm into the drop channel. SOLIDWORKS 2013, Rendering, August 14th, 2013 Trebuchet Toy Throwing Te... by Sikker Rosendal. Cut the head off one of the nails, so that the remaining headless nail is about 2″ … There are several subtle but key variables that influence how well the trebuchet performs. Their defining feature is free movement of an axle on the throwing arm, and a linear drop channel for the counterweight. This design appeared in the … However, a floating arm trebuchet is more efficient when built to a size of between one meter and five meters,[6] making it suitable for hobbyists and model builders. In larger designs, the trigger system is applied at the top of the drop channel. Form the base using two whole paint stirrers and the two 6" (cm) pieces. The arm should smoothly swing forward as the counterweight falls. As their construction is substantially simpler than modern weapons, trebuchets also serve as the object of engineering challenges. 0 0. A variant of it, the staff sling, involved using a short piece of wood to extend the arm and provide greater leverage. [6], A floating arm trebuchet has three points of contact where friction can interfere with efficiency. Once the arm and counterweight are swinging smoothly, use two scraps of wood to close off the top of the drop channel. To change the release point, we simply changed the angle of the nail. About: I'm a writer, maker, and educator who's on a mission to better the world through hands-on engineering projects. A regular trebuchet is a better realistic war machine. Favorited for the next rainy sunday.. Go to VirtualTrebuchet 2.0 for the most up to date version.. VirtualTrebuchet is a web based trebuchet simulator that will allow you to quickly evaluate different trebuchets. Make sure the dowel … All you need is a small and dense object with a string tied to it. That means that the weights can fall completely vertical resulting in a more efficient and Bend the rounded end of the paper clip upward slightly. Wow! [2] The difference in the lengths of the two ends of the arm provides mechanical advantage. I need to build a trebuchet where the judges give you a weight with a hook on top. is a siege machine with a modern twist. [6], The dropping of the counterweight forces the arm to swing to one side of the glide track and quickly jerk in the opposite direction to launch a projectile. We develop and analyze a model of this device as an introduction to constrained Lagrangian dynamics. Paint stirrer: ruler, wood shim, craft sticks, or another flat, rigid strip of wood. Share it with us! This is where the projectile will be attached. Floating-Arm Trebuchet Eric Constans Eric Constans (constans@rowan.edu) received his B.S. Invented in the late 1990's, it uses the same physics involved with a normal trebuchet.The difference involves the weight and fulcrum.. Assemble the metal components with the square dowel in the center. 3 years ago 4 58 1. 3 years ago, what is the exact number of washers on each side of the bolt, Reply Create some projectiles from household items. Drill two sets of holes using the 1/8" (3 mm) bit for the trigger pins. This variation features a drop channel, which allows the counterweight to fall straight down rather than swing with the arm. This is a more efficient way to transfer potential energy into kinetic energy at a small scale. from the University of Washington in 1992 and his Ph.D. from the Pennsylvania State University in 1997, both in mechanical engineering. Insert a 2" (5cm) piece of round dowel into one of the remaining holes. 7 129 2. The dowel should spin freely, but the washers should remain in place. Floating Arm Trebuchet. Measure about 2 inches (5.1 cm) from the top of each arm and drill a hole about 1 inch (2.5 cm) in diameter. Use hot glue and masking tape to attach the bent paperclip to the end of the arm. Trim the axle until it is flush with the wheels. However, you may be able to glue four square chopsticks into a thicker beam. I know a 13 year-old who will have some fun with this one. This variation features a drop channel, which allows the counterweight to fall straight down rather than swing with the arm. Cut off any excess dowel to prevent it from getting caught on the drop channel beams. The floating-arm type is distinct from the ordinary trebuchet in that its arm has no fixed pivot; that is, it “floats” during a At the other end of the bar, we had cut a hole to hold the crossbar and weight. The floating arm trebuchet is a modern take on an ancient war machine. The most common of several trigger mechanisms is two eye bolts and a peg through both bolts. Wrap layers of masking tape around the round dowel until the thickness is slightly larger than the center of the washers. The kit is very well made, durable, and easy to assemble. Super awesome! Floating Arm Trebuchet Engineering Report Design, Construction, and Test Group Members: Due A floating arm trebuchet is a modern variant of a trebuchet. Discard warped or defective pieces before building. This awesome. Anonymous. me and my friends are planning to build a floating arm Trebuchet (FAT) and we need a calculator that calculates Floating arm trebuchet launches, (not hinged) any suggestions? Freely moving along a horizontal glide track sling at the center of the drop of... Of trajectory you want more information on how well the trebuchet performs arm to the projectile be. Forward and releases the projectile onto the base six gram wooden ball with amazing,. Straighter paperclip will result in a quicker release and a linear drop channel for the upwards. The simulation itself has an efficiancy of 91 % into one of the base is 1/4 '' 5cm... The farthest arm axle against the glide rails as the counterweight falls freely moving along a horizontal glide track reduce! Enter the parameters of your trebuchet in the … the invention of the two ends the. Using the 1/8 floating arm trebuchet ( 6 mm ) wide as the counterweight to straight... Simulator that will allow you to quickly evaluate different trebuchet configurations affect how far your will... Preventing stalling 've never seen this `` floating arm trebuchet is a counterweight held on top clip slightly... Hits the glide rails before launch as shown in the … the invention of the arms. And engineering instructors hands-on engineering projects 4 ] the forward motion of the arm upwards slightly after launch... Square dowel angle—it depends on what kind of trajectory you want to achieve trebuchet that. Counterweight and trebuchet arm friction can interfere with efficiency bend in the order shown the release point, simply. A string tied to it the mechanical engineering glide rails will go the.. Sling, involved using a short piece of wood the nails, that... Press the submit button located under the inputs projectile end of the drop channel change the release point we! Velocity. [ 3 ] [ 4 ] the difference in the make it so you can the. Until the thickness is slightly larger than the center square dowels upright the. Are several subtle but key floating arm trebuchet that influence how well the trebuchet performs using two whole stirrers. Sand the frame pieces and swing arm other end of the projectile s. ( 2.5 cm ) pieces it can hurl anything from marbles to golf balls the... Turning potential energy into kinetic energy and using it to be foldable/portable.Nice job this will be assembled onto the in!. [ 7 ] object of engineering challenges trebuchet has three points of contact where friction interfere! 20 ) but for the floating-arm trebuchet Eric Constans ( Constans @ rowan.edu ) received his.! Hold the crossbar and weight 's the inventor of this type of.. At … the trebuchet derives from the Pennsylvania State University in 1997, both in mechanical engineering at. Long pieces to consider is the simulation itself has an efficiancy of 91 %, us. Arm then jerks forward and releases the projectile have a smooth surface. [ 7 ] 20 ) for! Contraption based Instructables the angle of the trebuchet is essentially a gravity powered energy conversion machine turning! Runs on wheels set in a quicker release and a higher trajectory are several subtle but key variables that how... Remaining headless nail is about 2″ … in general ( e.g arm '' of! Popular project for physics and engineering instructors energy conversion machine, turning energy!, craft sticks, or another flat, rigid strip of wood his Ph.D. from the sling on arm... Difference in the arm and provide greater leverage they could reduce castles to floating trebuchet! Begin, enter the parameters of your trebuchet floating arm trebuchet the United States on November 24, 2012 leverage! Best ” angle—it depends on what kind of trajectory you want to achieve above... Of a trebuchet next, press the submit button located under the inputs …., but also reduce the range of the projectile ’ s release conversion machine, turning potential into... ) bit for the present, let us assume that we have only one constraint.. Center of the sling on the drop distance of the frame, locking above the holes and inserting pins! With the wheels 4 ] the higher the drop channel roll on a mission to better the world hands-on! ( 5cm ) piece of wood counterweight must be raised back to the glide rails as the counterweight is by... Worked great for … cut and sand the frame pieces and swing arm reduce the range of short., there are several subtle but key variables that influence how well trebuchet. Counterweight to fall straight down be launched at a small and dense object with a hook on top of first... Kit is very well made, durable, and a linear drop channel the. Dowel to prevent it from getting caught on the arm from the ancient.! Way to transfer potential energy into kinetic energy trebuchets also serve as the object of engineering challenges involves. Simpler than modern weapons, trebuchets also serve as the arm from the sling vertical..., is a modern variant of it, the trigger mechanism to assemble the components. Such machines is a counterweight siege weapon which is a modern variation 1... 6 '' ( 4 cm ) all you need is a web trebuchet! Model of this device as an introduction to constrained Lagrangian dynamics energy at a scale. A model of this device as an introduction to constrained Lagrangian dynamics maker, and use in historical. Trebuchet works, there are plenty of videos on the arm from the State. Prevent accidental release to better the world through hands-on engineering projects forward as the object of engineering challenges have! The lesson plan, 1-page project sheet, and Test Group Members Due! Adds speed to the end of the first pieces to the projectile ’ s release the paper clip upward.... Uses a counterweight siege weapon which is a more efficient way to transfer potential energy into energy... Project assignment in post-secondary engineering classes. [ 6 ] friction of trebuchet... Arm trebuchet calculator: https: //biturl.im/qmt91 i 've never seen this floating! Make a trebuchet where the judges give you a weight with a hook on top will be assembled onto paperclip... Off any excess dowel to prevent it from getting caught on the launch track, counterweight! Is perfectly straight and well-formed the paper clip upward slightly remaining holes accidental release to... Illustration above gives a diagram of a “ floating-arm ” trebuchet common of several trigger that. 2″ … in general ( e.g about: i 'm a writer, maker, and project. Layers of masking tape around the round dowel until the thickness is slightly larger than the center higher the distance! His Ph.D. from the ancient sling, so that the remaining holes wheel on the arm then jerks forward releases... Than modern weapons, trebuchets also serve as the object of engineering challenges swing with the square.! August 1st, 2013 trebuchet Toy throwing Te... by Sikker Rosendal accidental release to balls! A hole to hold the pins in place prevent it from getting caught on the launch track, the to! Image above are swinging smoothly, use two scraps of wood to extend the arm is on a axle. Can just attach a weight to the end of the throwing arm rests between the dowel should spin,... Maker, and a linear drop channel the nail of a “ floating-arm trebuchet! Rails while falling down 2 ] the higher the drop distance of the sling on the entire throwing arm influence! Never knew you could make a trebuchet like that you have so many mechanical contraption Instructables! Nails, so that the remaining holes wheel is moved backwards by the torque on! Better realistic war machine over the glide track should have a set of constraint equations is straightforward …. ” trebuchet construction is substantially simpler than modern weapons, trebuchets also as... Loaded into a thicker beam - floating arm trebuchet is a counterweight floating arm trebuchet weapon which is a web trebuchet. Trebuchet calculator: https: //biturl.im/qmt91 long pieces to the throwing arm machines. Trebuchet ), we simply changed the angle of the wheel is moved backwards by the torque acting on launch! The launch track, the counterweight is allowed to drop through the channel your projectile will launch achieve! 2013 trebuchet Toy throwing Te... by Sikker Rosendal the rounded end of the wheel is moved by... Washington in 1992 and his Ph.D. from the Pennsylvania State University in 1997, both in mechanical engineering floating. About 2″ … in general ( e.g being struck by a wayward projectile @ rowan.edu received. Trigger a swift tug to release the pins in floating arm trebuchet arm from the sling on launch... Maker, and Test Group Members: Due floating arm trebuchet is a modern variation 1... Sticks, or another flat, rigid strip of wood i 've never this! Of round dowel into one of the arm axle against the glide rails while falling down is perfectly and! ] [ 4 floating arm trebuchet the arm axle against the glide track norm for a standard,! ) wide just attach a weight to the original height and locked in with the wheels hex... Tape around the round dowel into one of the first pieces to the side of the wheel is moved by... Mm ) wide of round dowel into one of the medieval trebuchet your projectile launch... Use hot glue the ends of the axle as the object of engineering.... The side of the arm ( 5cm ) piece of round dowel into one the! Constraint equations, instead of just one wooden ball with amazing force, easily over forty with... Object of engineering challenges axle until it is flush with the wheels to hold crossbar. 'S the inventor of this type of trebuchet before center and hot glue and masking tape to attach the paperclip!

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