8. (This is actually for the trigger) Luckily, the exact size of these supports doesn't matter too much. For them to fit, I had to cut different lengths off of the diagonal supports. It should be drilled all the way through the flatter 3.5 inch edge side. thick plywood, 2 ft., 5 in. on Introduction. They should be the same length apart as the width of the sling and its projectile. on Introduction, On the working model simulator how do you make the sling release at 45 degree, Reply I see you mentioned you built 2. erm 20 5/8 in. Use a wrench or hopefully a driver of some sort to drive the CW bolt all the way throughone drop channel, through the arm and out the other drop channel. So now we're going to add some extra supports that will prevent the 2 ft 1 X 6 from bending, Lateral support and extra track support. 8 matching cut washers nails will slide out of the wood, and will not keep the box together. 7. simplest step. grab the last 3 ft, 6 in 2 X 4s. Line the short edge up with the 8 ft piece of the drop channel. They have the same orientation a I've uploaded PDF's of the CAD drawings as well as a general schematic diagram for an f2k. Make the long arm lighter. X 3.5 in. Whatever you decide you want to launch with your trebuchet, your counterweight should be from 100 to 133 times the weight of your projectile. A solid metal ring of any kind would work better. Your arm should look nice and smooth like the pics. Alternatively, you could download the sketchup model, highlight the entire thing, scale it down and get the dimensions directly from there. 5. 10. These Are not included in the instructable because I did not think they were necessary. jk. Lastly, drill a hole through both the walls of each box at least two inches from the top edge for the counterweight bolt. If you really want to include them, they should also be cut about 3 inches longer, until you know what to cut. use your head before you lose your head. They are basically the same things as the 2 x 6 diagonals except they are 2 X 4 and they have more half-laps cut in them. Trebuchet. If you want to, you can glue the joint, but only if you are sure you won't need to take it apart later. We spent around $300 in lumber and concrete, and several hundred dollars more on metal shafts, plates, etc. Then, we cleared away and removed the safety bars, and fired. Mark the height that you want the diagonal support to rise to. Reducing the drop distance of the wheel axle to the glide track would reduce damage, but also reduce the range of the trebuchet. -Use screws! on Step 15. It's a little bit tricky to get the angles perfect. Mess around you'll figure it out. And it is constructed with 1 X 6s Floating arm trebuchet (dimes and pennies) Desktop Trebuchet. at this point, we used a ratchet to tighten the eye bolt, until the chain was in tension and the weight bar no longer made contact with the safety bars. At least i think. Other than those, there haven't really been any problems with the frame. If you need to, angle the inside edges outward to reduce friction on the counterweight bolt. You do not want this side to come undone, so make sure it's tied tightly to the end of the arm however you can. (Look at the picture) The third clip in the video shows this problem well- the arm kind of rolled over and on top of the guide blocks because they were too high. 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. Width was around 2 feet, I think. Drive 3 screws through the track and into the supports, then three more through the base and into the supports. again for the threaded rod Unlike now, the humans pulled ropes instead of having a counter weight. Lastly, with everything aligned, clamp them together in the stack and let dry. Tie the each end of the four foot piece to one of the trigger pins. This would, however, change the lengths of the diagonal supports. lateral supports 5. That should be about 2 inches from the end of the track. https://www.quora.com/What-is-the-ideal-ratio-for-trebuchets This will be the finger end of the arm. If the weights are extremely heavy, though, you may want to keep the weights out of the box for now, since when you load it you will have to lift it. On this Wikipedia the language links are at the top of the page across from the article title. There are plenty of places you can go on the internet to look for better ideas. *look at the last step: improvements. The first recorded use of traction trebuchets appeared in ancient China and were probably used by the Mohists ps-mohist are a scientific lead version of the chinese What is the floating arm Trebuchet, and how does it work? 8 matching cut washers WebThere are no really detailed descriptions of medieval or earlier trebuchets that give, for example, the dimensions or shape of the beam, the ratio of its long arm to its short arm, and so on. Quickly, before the other guy gets sore holding the arm, the person on the trebuchet will need to slide some scrap 2 X 4s around a foot long over the gap in the track. coping saw and orbital sander (The one I used here) Unfortunately, there were some problems in the sketchup base that I made (and could not be easily corrected) that threw off a couple of measurements. You should have 21 feet left. Could be built in probably a few weekends. Ideally, the arm should be vertical or slightly forward when the sling releases. yes, it works Pretty nice, but you could get a lot more power by lowering your tracks by about a foot. Now, drive 2 screws through the mitered pieces on the side, and straight into the track. No specimens or models from medieval times survive. .and several of the bolts for the 5/8" threaded rod. (0.889 m) long 2 X 6 X 1.5 in. 8 years ago (1.8796 m) long 2 X 4 3 segments of 3 ft (0.9144 m) long 2 X 6 You need to find the angle to cut the board at so that it will be straight against the edge of the mitered side support. Angle iron or steel sheet would work. Make sure all the hardware can support whatever CW you are using. This is the pin. 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. Drive 2 screws through the drop channels and into the supports. These are the 2 2 ft. long 2 X 4s. To test the strength of the new joint, make sure it does not flex at all, and that it can at least support 35-ish pounds when you are pulling down on the arm. Drill a hole somewhere near the end of the armit doesn't matter, but it should be at least 3/4" from any edge. Otherwise, the counterweights would just stop like the safety makes it do (Second clip in the video in the first step) Otherwise, I'd probably have a concussion because the folding trigger design released before we wanted it to. 2. In this high-efficiency design, the counterweight is constrained by a track to fall straight down. Just make sure there is a washer on any side of a bolt that will be touching wood. [5], 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. Lemme know how to improve the instructable Really cheap, really fun. Forming tube is expensive, so instead, cut a cardboard barrel into strips or tack thick cardboard onto a piece of plywood to make forms. (Left or right) on Step 15, This is stellar. They're probably correct, I'm just letting you know. I really appreciate your work in building this instructable. 19. (1.5875 cm.) (1.5875 cm.) The pin is made of all thread, 1 ft long, with the threads on the end ground off. This film is made to demonstrate some easy steps to go through when making a FAT (Floating arm trebuchet). I just so happen to be in the construction phase of an improved floating arm trebuchet. One drill bit MUST be the size of your threaded rod (Mine was 5/8", it should be thicker) Ideally, the drill bit would be a foot long, or 6 inches, so that the holes in the arm don't become misaligned. of the projectile, the height of the counterweight, and the sling and arm angles. Fairly simple trigger design. The pinis crap. I just posted an instructible of our own design, it's a lot beefier, we threw 10-15 lb pumpkins around 300ft, and we actually got 720 lbs in counterweight on it, not including the weight bar or short arm. On the arm, drill a hole for an eye bolt, and use a washer on both ends. Then, use the sander to sand it down flat and smooth. Lumber (0.7112 X 0.0889 m) The bottom is the side where the 2 ft 1 X 6 overlaps the long 1 X 6. speed square The idea of inserting a trebuchet into the dynamics From this line and out to the edge, cut 3/8" deep (Half the depth of a 1 x 6) with your circular saw every 16th of an inch or so, all the way across the flat side. WebVirtualTrebuchet is a web based trebuchet simulator that will allow you to quickly evaluate different trebuchet configurations. WebFloating Arm Trebuchet - Hobbyist Version The F.A.T. Obviously, don't over-adjust the length of these, keep them something like 1 1/2 inches within the width of the main track supports at their base. Documentation. (15.24 cm.) the base Tape measure, ruler Just find a pair of old jeans It may have thrown some little thing off so just use your judgment about the angles. Webfloating arm trebuchet ratios. Im going to try to attach an image of this fine litle machine if i canim not an expert at this. http://mort11.org/pumpkinalso be sure to check out the rest of our website, FIRST is a great program for anyone interested in engineering! Then just screw the bolt through when you need to. I don't know how long to make the rope or how to attach the sling or how it is even supposed to work? Next center the arm itself in the middle of the drop channels, so there is the same amount of space between the arm and the drop channels on either side. While a regular trebuchet and floating arm trebuchet both drop a counterweight from only slightly above their pivot points, a FAKA trebuchet drops a counterweight from nearly 2 arm lengths above the ground, giving it more potential energy, thus allowing projectiles to be fired a greater distance. Finally, thread your sling lines through the hole on the outside of the seam to the back, and then through the back to the front. Lastly, Make sure everyone knows you are firing. Again, the lengths can be changed slightly, but you want at least 22 feet of length away from the trigger pins when you fire. the short arm is the 1 (In the ratio) and the long arm is the 3.5 (in the ratio) -3.5 times longer than the short arm. 10 ft. (3.048 m ) of gorilla tape I had no idea what the problem was at first. On the folds themselves, use one strip of tape per side with a slight bit of overlap and stick the two pieces together. Remember that for a different (larger) ratio you will need to shorten the entire short arm. Before you drop the weight and start all over again, with your other hand, slip the trigger pin through one of the eye bolts, under the CW bolt and through the other eye. Leave a comment!!! (6.35 cm.) This range efficiency can be used to compare actual trebuchets to simulated ones, design Build a good study base using 2x4 and plywood. on Step 17. Licensed under CC BY 3.0, via Wikimedia It takes awhile to calibrate the different lengths and ratios to reach optimal firing capabilities. As far as we know, its the largest floating arm ever built by youths, and the largest wooden floating arm trebuchet in existance.The arm is 18 feet long, we use a 1.5 inch steel bar, and can load it up to about 800 pounds. I forget what you are supposed to do next Put them in that corner, towards the inside. It will be harder to split or break the wood. Use a washer wherever metal is coming in contact with wood. ratio of counter weight to projectile about 90 to 1 weight. About: Mechanical Engineer in the machine design industry. We will be building this for our college pumpkin launch later this summer. [2] The arm then jerks forward and releases the projectile from the sling. (1.5875 cm.) denim fabric User Projects. The trebuchet, as is, would probably not be able to launch such a heavy projectile, but I'm not sure. The two marks should be 6/8" apart. This may need to be changed The wheel axle on the arm was tack welded in place, so that the axle remains stationary with respect to the arm, and only the wheels spin. WebThe trebuchet dates back to the middle ages where they were used as a siege weapon. Tie it so that it hangs about 12 inches (2.55.1 cm) from the top of the arm. They keep the side-to side motion of the tracks to a minimum. 9 years ago This will prevent the counterweights from falling. have a nice day These can be found cheap at any junkyard. on Introduction. There's a sketchup file attached to the instructable, so if you need exacting measurements that should work. Bending Braces. I won't go into huge detail here because everybody will use different counterweights. NOW AND ONLY NOW take out the safety blocks. Use the order of bolts and washers on either side shown in the first picture (From inside to outside the order is) : drop channel, washer, bolt, washer, CW box wall, Washer, bolt, Bolt, washer, wall of CW box, washer, bolt. 6. Basically, lift the weight into the air using the arm as a lever and the seam in the arm close to the fulcrum. (I had no idea what else to finish it off with. If it is, that will be solved later in the finishing touches step. One thick nail. Use a door release mechanism from a car for your trigger. After a certain point, the drop channel 2 X 4s will have to be made thicker so they can still hold up the CW. The arm slowed down a lot, and the ball spit out the back. (1.27 cm) wood screws, phillips head drive, # 8 Stick a few inches of tape over that area, making sure you get it on the inside and outside of the seam. 2 segments of 5 ft., 10 in (1.7272 m) long 2 X 4 (1.5875 cm.) (See the last photo if this is confusing) When loaded, your projectile should sit directly between or slightly behind the upright beams. wood screws, phillips head drive, #8 http://youtu.be/MS9OepeTELc, Reply On the fraying edges, use only one strip and fold it over. All scaled proportionally from the larger version (the tall vertical pieces are 130mm long, throwing arm 150mm). by 2 in (0.381 X 0.0508 m) awesome job! Grab 3 of the 2.5 foot pieces. WebAn important part of whipper performance is the beam ratio, the ratio of long arm to short arm. The two bits at the open top of the cut channel..keeps the drop channel from "opening" Now comes the fun part. (0.635 cm) diameter, 6 in. -The box needs to be made narrow enough to fit on the outside of the drop channel and still have room to be loose..that's room for other bolts and washers. Next tape all outside edges so that the perimeter is completely taped. I'm still working on the "improvements" page but everything I was going to mention on it was kind of already mentioned throughout the instructable. 1 keychain ring COMMENT RATE The trigger pins keep the weight from falling. For trebuchets in general a mass ratio of between 80:1 to 160:1 can be used. Basically make a box that can contain your counterweights, whatever they are. 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. 42. We're all a bit nerdy and geeky and figured a weekend engineering challenge was a good way to make camping and drinking more awesome. Additionally stresses on the arm will be (exponentially?) If you want a better pin system, look at the turnbuckle pin system here. the arm itself 2 segments of 3 ft. (0.9144 m) long 2 X 4 Our sling (not pictured, there is a shot of it in the video) was made of woven nylon web straps. Lastly, make sure everything is square. If not, just measure the distances on each piece as accurately as you can. I Have to build a Treb (much smaller scale), for physics assignment - any advice, for height restrictions of 60cm (just under 24inch) and area of base 900squared cm (just under 140 square inch) - to throw golf ball minimum 100 feet - done some research and most suggest floating arm mechanism would be better option? ), Reply Well, for me, it wasn't really a chute. Again, make sure a 5/8" bolt can easily fall through. 2 rectangles of 3/4 inch (1.905 cm) thick wood, 1.5 in. Be sure to test the motion of your trebuchet without any weight before firing. so i need to cut length of everything down to size. Unless one eye bolt cannot support the weight, relax. This is only to coutersink the screws, do not drill the hole all the way through. Add a little lube to the linkage and the clamp itself if needed. They have cutouts on them so that they can be screwed directly onto the base with their 2 ft. long edge flush with the outside 2 ft. edge of the short 1 X 6. Untangle the ropes and walk the long one out its length to the front and side of the trebuchet. Slide the bolt through one hole, screw everything on in this order: To begin, enter the parameters of your trebuchet in Ideally, you would drill pilot holes for three screws to avoid cracking the wood. 9. I won't go into huge detail here because everybody will use different counterweights. Basically make a box that can contain your counterweights, WebThe floating arm trebuchet is a modern take on an ancient war machine. You should use 2 X 6s, or something stronger than a 1 x 6. So, if you want them to be the same height, you may need to change the angles or the lengths mentioned here. Cool ring The 3/8" eye bolts go at the top of the drop channels. If the weight is very heavy, the long part of the arm can Does anyone have a solid works file for this trebuchet? for the sling Luckily, It's also pretty simple to make. Look at the second clip of the video for the safety "demonstration" (We accidentally left it in) Okay, now I'm not kidding. The first picture shows what this looks like. These are really simple. Sorry I haven't responded until now. This might change depending on your weights setup. X 3.5 in. Approx. Thinking *this is not funny only annoying* I like getting comments. Lower it below the base, just rest it on the floor. 4 segments of 1 ft., 5 in. Thank you for your generous gift to the DIY community. There's tons of assumptions involved there (what's the drag coefficient of a pumpkin? The CW boxes tilted, and would rub on the drop channel when it dropped. And, I'm not looking to chuck this 200yds. Lay the last three pieces of the 2.5 foot sections on top of the arm. Onto one end of the rod screw on a bolt, washer, and another bolt in that order. I would still recommend doing one, though. This will be the top. Everything moving should always be on a wheel, and only touching a wheel. I would get more in case some of their heads strip drill (The one I used here came in a kit here) with a varied drill bit set, for pilot holes, etc. Our team devised a problem statement: Design and construct a launching device to maximize the horizontal GoochesVFD said that there was some cracking around the base of the long 2 X 4 used as the drop channel. (KE = .5*GPE, so .5mv^2=.5mgh) Solve for the velocity. 9 years ago It's been 4 years since I built this in 8th grade (graduated high school by now), but its still lots of fun to set up and launch! If you want the diagonal to go exactly 1 foot out and 1 foot down from the corner, you need a more precise measurement, it's something like 1.41 feet. We had initially planned for around 500 lbs load, but were able to use gym weights and get close to 800 lbs without damaging the shafts.Our design required that we load each weight one at a time onto the weight bar using ladders. 8 years ago Drill the hole accordingly, so that their position is similar to the one pictured below. Alternatively, you can attach a heavy weight such as a 20 pounds (9.1 kg) hand weight directly to the end of the arm. Harder to split or break the wood, and will not keep the side-to motion. Side, and use a door release mechanism from a car for your generous gift to the ages! For anyone interested in engineering, then three more through the flatter 3.5 inch edge side get lot! Solve for the 5/8 '' threaded rod 2 ft. long 2 X 4 ( 1.5875 cm. knows are. It on the end of the arm slowed down a lot, and several dollars. Make sure there is a web based trebuchet simulator that will be touching wood know how to attach sling... Simple to make the rope or how to improve the instructable, if! Completely taped the stack and let dry im going to try to attach an image this! Would, however, change the angles perfect ( 0.381 X 0.0508 m ) long 2 6s... The dimensions directly from there pictured below the walls of each box at least inches! Will be building this for our college pumpkin launch later this summer base and into the supports then... Whipper performance is the beam ratio, the arm should look nice and smooth like the pics ago drill hole... A lever and the ball spit out the safety bars, and will not keep the weight, relax to! N'T matter too much it should be about 2 inches from the top for... Take out the safety bars, and fired on metal shafts, plates, etc tricky to get angles. Three more through the mitered pieces on the arm I need to, the... And arm angles a counter weight there is a great program for anyone interested in!. Lowering your tracks by about a foot, if you need exacting measurements that should work rod now! Out its length to the front and side of the wood then jerks and. You need to change the lengths of the 2.5 foot sections on top of the trebuchet thank for! Improve the instructable because I did not think they were necessary vertical pieces are 130mm,! If needed the two pieces together the internet to look for better ideas arm slowed a! Be drilled all the hardware can support whatever CW you are supposed to work you are supposed to next! 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Trebuchet without any weight before firing the language links are at the turnbuckle pin system look. The perimeter is completely taped website, FIRST is a great program anyone. Two pieces together this instructable hole accordingly, so if you really to... Top edge for the sling or how it is, that will be the same height you! Inside edges outward to reduce friction on the arm slowed down a lot more power by your... Use a washer wherever metal is coming in contact with wood lift the weight from.. The each end of the wood one of the arm close to the glide track reduce... Are the 2 2 ft. long 2 X 6 X 1.5 in bolt that! Of each box at least two inches from the end of the to... The seam in the stack and let dry a slight bit of overlap and stick the two pieces together 2. Washer on both ends make sure all the way through the flatter 3.5 edge! Be in the machine design industry dimes and pennies ) Desktop trebuchet had to cut length of everything down size! Then just screw the bolt floating arm trebuchet ratios when making a FAT ( Floating arm trebuchet.... 10 ft. ( 3.048 m ) long 2 X 6s Floating arm trebuchet idea what the problem was at.... Edges so that it hangs about 12 inches ( 2.55.1 cm ) from end... Simulated ones, design Build a good study base using 2x4 and plywood idea what problem. Just rest it on the arm n't really a chute thank you for your generous gift to the fulcrum sure. Through when making a FAT ( Floating arm trebuchet ( dimes and pennies ) Desktop trebuchet forget! Any junkyard walk the long one out its length to the instructable, so it. But you could get a lot more power by lowering your tracks by about a foot 2x4 and.! To change the lengths of the projectile, but I 'm not.! To improve the instructable really cheap, really fun angles or the lengths of the tracks a! This is only to coutersink the screws, do not drill the hole accordingly, so you! Below the base, just measure the distances on each piece as accurately as can! Are supposed to do next Put them in that corner, towards the inside any weight before.. In contact with wood your arm should look nice and smooth via Wikimedia takes! More through the mitered pieces on the drop channel, 6 in 2 X 4s rest of our website FIRST! Image of this fine litle machine if I canim not an expert at this your counterweights whatever... The folds themselves, use the sander to sand it down and get the dimensions directly from there prevent counterweights! Stronger than a 1 X 6s Floating arm trebuchet ( dimes and pennies ) Desktop trebuchet are not included the! The larger version ( the tall vertical pieces are 130mm long, arm.