Now, measure that same distance on the base. diameter threaded rod, coarse thread If this happens, use it on a hill or place two very thin pieces of scrap wood under the base, directly under the drop channels. Use your head before you lose your head (Look at the picture) Documentation. 2. Ok, so this is what the entire bulk of the trebuchet rests on. It's 6 feet long and 2 feet wide. And it is constructed with 1 X 6s That's its fa And it is constructed with 1 X 6s WebExample: Floating Arm Trebuchet The floating arm trebuchet is similar to a fixed fulcrum, with the exception that the fulcrum of the arm can move horizontally, and hence should be tested the same way, with one additional test to check to ensure the arm does not roll downhill. Lean the supports in towards the drop channel as they go up so they don't slip out. 3. refold the ends so that the seams are both at least 3/4" from the edge-it doesn't matter if they are on the same side or not. Without the other, the tracks may not be aligned or the width of the drop channels might narrow or widen (Not staying even= bad) The eyes face inward. [4] The higher the drop channel, the more energy is released, but this puts more strain on the mechanism. Do the same with the bottom of the board, the part that you held against the bending brace. First, grab two of the 8 foot long pieces. Line up one edge of the bottom of the track with the 2.5 foot mark. Now you simply lay the 6 ft pieces across the supports, lining up the edges, and drive three of the 2.5 inch screws into through the track and into the supports. Their defining feature is free movement of an axle on the throwing arm,[2] and a linear drop channel for the counterweight. [5] Friction of the wheel on the arm axle against the glide track should be managed in a similar way. If the weight is very heavy, the long part of the arm can Do you still have the Matlab file? wood screws, phillips head drive, #8 diameter threaded rod, coarse thread This would eliminate cracking and make the drop channel much stronger. It will differentiate depending on your ratio. For the arm assembly Allow about 1 week before firing your trebuchet. As it turned out, our design was over built and held up well. (See the last photo if this is confusing) When loaded, your projectile should sit directly between or slightly behind the upright beams. There are plenty of places you can go on the internet to look for better ideas. i was hoping you could tell me what the release system was rated for and if you have any recommendations on where i can acquire a quick release, 8 years ago Plywood also included in the arm I made my own (although on a slightly smaller scale. Put them in that corner, towards the inside. This might change depending on your weights setup. Other than those, there haven't really been any problems with the frame. But make sure you go to the website for wheels that I recommended in the Instructable to avoid paying too much for wheels. Drive 2 screws through the drop channels and into the supports. WebAn important part of whipper performance is the beam ratio, the ratio of long arm to short arm. First, obviously, just lay the arm in between the drop channels (Just the middle of the treb) Then fold in on top of the other one to crinkle the pouch into a more pouchy shape. 12. (2.54 cm.) the next 3 specifically show the dimensions for the short side. 8 matching cut washers For a traditional trebuchet, the optimum weight ratio is 133:1. The part of the war machine that means business. Oh man that is awesome. WebFloating Arm Trebuchet. Onto one end of the rod screw on a bolt, washer, and another bolt in that order. 5 years ago. I've seen some really nice f2k's that have the wheels jump the gap on a ramp, but that would require much more engineering calculations and dynamic tuning than we had time for. I would love to see it while being constructed and finished. Cut them low but long out backwards. Make sure there is glue all over them. 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. 10 1/4 in. Lastly, These are the trigger pins. about 250 2.5 in. For me, this was a little more than halfway through the side pieces. I keep them in one of the mitered side support screw holes so I can easily reach them once I get the CW to the top. So, the first one is more of those charming "Extra supports." Really, you just want something to support your sling during the first part of the arm's swinging so the sling is not dragging on the rough ground. 6. on Step 15. A note about the guide blocks: Yeah, this happened to me. I'm using this kind of trebuchet for an assignment, and the ratio of our weight to out projectile is about 1:200. would this kind of trebuchet be better in this case than a traditional trebuchet? GoochesVFD said that there was some cracking around the base of the long 2 X 4 used as the drop channel. ratio of counter weight to projectile about 90 to 1 weight. (0.7112 X 0.0889 m) For the trigger you will need the: Have a nice day WebThe Cardan Gear Linear Motion Trebuchet is an adaptation of the motion found in a Cardan Gear adapted to a straight track-drop trebuchet. We are building one now, it has been lots of fun for the family. The Floating Arm Trebuchet The trebuchet is a medieval gravity powered engine of siege warfare designed to hurl a projectile, such as a heavy stone or a diseased animal, at a distant target such as castles. (6.35 cm.) Ok, now repeat the entire process mentioned above for the "short" side. 7. He was right. The key ratio of an arm is anywere between 3:1 and 5:1. 18. MAKE SURE THE EYE OF THE TRIGGER PIN IS FACING THE FRONT OF THE TREBUCHET otherwise you will have to switch it. Punch the holes centered as shown and directly on either side of the seam. 3. First, I'm going to talk about some other improvements that are more important than the arm. Still, I would make it a bit thicker. Be sure to test the motion of your trebuchet without any weight before firing. (1.5875 cm.) Otherwise, the arm would derail a lot more. The trigger held up well, but it did take a pretty hard tug to get it to release with max weight. I'm going to assume that you are drilling one long hole through all of the short arm pieces. Projectiles can fly backwards, so keep people and cars AWAY from this area. I used the trebuchet frame as a fulcrum to lift it in the air. I forget what you are supposed to do next And send me some pictures :D. I tried to reply but it wouldnt let me so this is my other option. For the diagonals you will need the Remember you need to make two of these. Do some experiments, that part is the most fun. (I saw a car roof get crushed by a pumpkin flying backwards)Use a long trigger rope and keep yourself at a safe distance.Have fun. If you have a router, it would be easier to do this by just cutting away the material. The more you pull the edge over the other one, the deeper the pouch will be. The Arm. It's a little bit tricky to get the angles perfect. 9 years ago I won't tell you which one was the best yet, although you can probably guess. This may need to be changed (0.635 cm) bolts, matching thread Okay now you need to cut the axle. The design and construction of such machines is a popular project assignment in post-secondary engineering classes.[3][4]. 1. 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. Today they are used mostly for recreation and education. May need to be hanged if the diameter of the threaded rod is changed (if you do it, let me know; I'll tell you how to make fireball projectiles), 7 years ago Or you could buy a longer beam to begin with. You can pretty much change the positions of these pieces as much as you want, but the positions they are in now worked great for me. Phsstpok's rule works well in determining the BR, maybe better than with HCWs. 4. I did not have a drill bit long enough to go through all of the 2 x 4s of the short arm, so I had to drill individual holes in each individual 2 X 4 and hoped that they lined up. 3. On the end of the arm, there will also be a nail, or some sort of strong metal pin. Again, not critical. The first picture shows what this looks like. Unless I've forgotten something, I think we're done. Drill a hole horizontally and squarely directly through the track. Next, grab you trigger pin and just hold it beneath the CW bolt. Im going to try to attach an image of this fine litle machine if i canim not an expert at this. (0.4318 m) long 2 X 6 For each track support, you should use 3 of the 2.5 inch screws, screwing them from the bottom of the base and up into the supports. Push one of the corners of the diagonal support next to the bending brace, but keep it one the base. excellent site for cheap, strong wheels http://www.thecasterguy.com/ Reply 19. Hopefully everything has been built straight and solid. again for the threaded rod 3.5:1 worked best in my experiment, and there is a ton of extra material adding weight to the long arm. there are small cracks throughout the trebuchet now because I was lazy. thank you, Reply .and several of the bolts for the 5/8" threaded rod. To include the jk. Use a bowline. Luckily, I eventually lined up the holes. Place the tips of these boards 1 foot from the end with the tiny rectangle of wood. Pretty nice, but you could get a lot more power by lowering your tracks by about a foot. 8. This new and improved 21st century version of the trebuchet uses a modern understanding of physics and engineering principles for incredible power and range! Leave a comment!!! Consider cost and use whatever spare or donated materials you can find. Place your projectile in the sling. Now we're finally going to add the last few lateral supports and the guide wheel. use your head before you lose your head. This thing is powerful, which is why you need a trigger. For the weight I used ( 36 pounds) a 5/8" HARDENED STEEL rod MIGHT work. If you really want to include them, they should also be cut about 3 inches longer, until you know what to cut. 50 pounds that was used here. of the projectile, the height of the counterweight, and the sling and arm angles. Diagonal Track supports. The tighten the bolt against the short arm and the bolt on the very outside. 2 1/2 X 10 eye bolts Just on top of the tracks. Virtual Trebuchet is a free web based trebuchet simulator. 3. [2] This allows for a higher drop height for the counterweight,[2] which is allowed to fall down a sturdy linear vertical "drop channel". Then, we cleared away and removed the safety bars, and fired. A thin steel cable might work better.Axles and Shafts: We used small segments of steel pipe and drilled holes in them to make bushings. Once smooth motion is achieved, begin adding weight, but do not fire anything until a max weight test is done. 11. Lastly, drill a hole through both the walls of each box at least two inches from the top edge for the counterweight bolt. I haven't noticed any cracking with a 1 pound weight being fired at full speed, but a 6 lb weight will exert much more force on the arm because of its higher inertia.. -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. Do you have any instructions or tips perhaps? This may need to be changed. They have the same orientation as the main track supports. Make sure your projectile is in the sling (Yes we do forget that a lot) the ring is on the pin, the CW bolt won't get stuck on the eye bolts coming out of the drop channels and that the safety blocks are still in, along with the weights (Obviously) In response to urbanmx, this was our very first trebuchet. 1. The person holding the arm up can relax. It worked fine for me, though. The person standing on the trebcuhet is no longer in danger unless he drops the bolt on his foot. Then, measure 3/8" from either side of this mark. It was built to be strong, but because of that it's a bit heavy and inflexible. This variation features a drop channel, which allows the counterweight to fall straight down rather than Luckily we caught it and injuries were avoided. Tie the longer end of the rope through the hole in the end of the arm. Can the trebuchet launch a 6-lb shot? You also want to keep the track in a straight line, otherwise the wheels will fall off the edge. trebuchet main track supports and track.tiff, Strap-On Cleats for Ice and Snow Traction, Hollow Wood Surfboard - Plywood and Cedar. WebThe floating arm trebuchet is a modern take on an ancient war machine. 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. At least i think. Thorsen said: boohbah said: unfortunately lordbob is no longer with us , he suffered a fatal blow to the temple from a golf ball. May need to be shortened, look at improvements 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! They must be perfectly straight and lined up. Tie a metal loop on one side of the rope to go onto the pin, and tie the other end to one end of the sling. 1. This list of materials is copied directly from my science fair project. It includes what I used at the time. The lumber list is really long, but Threee previous sections are for the counterweight boxes. 7. These are really simple. The first 5 pictures (except the first and second) specifically show the dimensions for the "long" side. on Step 17. (0.2413 X 0.2286m) Remember that for a different (larger) ratio you will need to shorten the entire short arm. 6. Webof the pivot, mass and inertia of the arm, mass of the projectile, ratio of the pivot/arm's center of gravity, mass of the counterweight, wind speed, and release angle. Lastly, cut through the plywood rectangle so the wheel does not bump over the edge of the plywood as the arm falls. (0.635 cm) washers, matching carriage bolts Bending Braces. So if I could toss the weight a 100yds would be perfect. Now I'll tell you how to lock load and FIRE! First, grab your counterweight bolt (hopefully thicker than 5/8") and use some sort of clamp to keep it pushed up against the top piece of wood, as if it was being loaded. (Safety blocks explained later) This step is fairly simple. The two bits at the open top of the cut channel..keeps the drop channel from "opening" The other end should be open. Not a big deal, but if you want them to be the same height as the ones here, then you need to change the angle of the diagonals. While the floating arm design can have a lighter frame than a traditional trebuchet because the overall forces produces are less,[7] the impact of the arm on the glide track will cause eventual damage and may need maintenance. Have someone stand at the back of the trebuchet, next to the arm (To the side) It would also bend out of position because of the force of the swinging projectile. Otherwise, the washers in between the CW box and the channel will be smooshed up against the drop channel, creating friction, which is bad. Your arm should look nice and smooth like the pics. WebLaser Cut Desktop Trebuchet. The straight track drop is an idea used in a FAT (Floating Arm Trebuchet), or in our Baby ASOK (Arm Slides Over Cam). Lastly, hammer a nail anywhere into the end of the arm. WebHow to make a Floating Arm Trebuchet. 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. 2 rectangles of 3/4" in. Taper the arm from a full 3" at the axle to 1" at the finger end of the arm (Fig. (1.5875 cm.) Thats a bit longer than 7 feet because i rounded 7 4.5 up, it was really 1.55555555 As long as it's a strong, flexible cloth pouch that is big enough to wrap around your projectile, It's fine. If you can't get it to the top in one shot, use the supports. although I'm still not quite sure how that happened. With the help of the Siano paper we were able to engineer a very effective machine. 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. If you need to, angle the inside edges outward to reduce friction on the counterweight bolt. These are the horizontal beams that are used as the track. A shorter length sling will work better for lighter projectiles, while a longer length will be better for heavier projectiles. Smash many pumpkins.Note:Time was of the essence on this project. Tilt the diagonal slowly over to the drop channel, keeping the bottom corner on the base and next to the bending brace. WebFloating Arm Trebuchet - Hobbyist Version The F.A.T. Untangle the ropes and walk the long one out its length to the front and side of the trebuchet. 7. Look at the pictures to see this; it's kind of hard to explain the placement in words. on Introduction. fourth through fifth picture will show this. 2. Need some advice please. awesome job! for the carriage bolts Make sure the washers do not interfere with the drop channel. nuts, coarse thread Next tape all outside edges so that the perimeter is completely taped. Credit for the trigger design goes to my neighbor, Joe, who thought up the design after seeing how bad the folding trigger design was. At the current position they dont utilize all of the work you did lifting your weights.Here is a floating arm that two other students and I from FRC team 11 MORT designed for punkin chunkin in Delaware. I don't remember the exact dimensions, but I think it was a little bit taller than 8 feet, and about 6 feet long. 91.4 meters. I wish I'd have seen yours before we designed it, I went with a 2:1 ratio for the arm, and we may have been able to make it a bit longer. They're probably correct, I'm just letting you know. We did indeed build a small scale floating arm trebuchet very close to the specifications your physics assignment is calling forand it has demostrated ability to throw small "bouncy balls" from a vending machine 270 feet, and big bouncy balls (slightly bigger than a golf ball) over 180 feet. The floating arm trebuchet uses a counterweight held on top of a tall drop channel to transfer potential energy into kinetic energy. I have no clue what it is for f2k, but it is a more efficient trebuchet. You can always add on later, but it's easier to get a long enough one in the beginning-before you glue everything together. Short sides of the base wood screws, phillips head drive, #8 I'll explain later coping saw and orbital sander (The one I used here) Now, cut very carefully and very straightly down the lines you made. Upon releasing the trigger, the counterweight is allowed to drop through the channel. Use a wrench to thread the threaded rod through the holes you made..make sure it fits and is level. it's smoother, faster, and prevents grooves from wearing in the wood. I would greatly appreciate it if i can take a look at it. Really cheap, really fun. Ideally, the arm should be vertical or slightly forward when the sling releases. 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. This book is a compilation of step-by-step instructions for how to build nine different types of catapults and trebuchets, including plans for: A PVC Pipe Trebuchet, A Tabletop Trebuchet, The World Famous Floating Arm Trebuchet, The Historical WarWolf Trebuchet, A Rat-Trap Catapult, The Mangonel (or Onager), The Greek Ballista, a You can use a clamp and a tape measure in combination to figure out the right lengths before you cut them. upper arm/lower arm length 4 9/16 inch (115mm) / 2 3/32 inch (53mm) Remember, smooth transitions. I have to make a Trebuchet for my Engineering product, and it must be no more in height than 80cm, so what do you think are the best dimensions and ratios for it? I will be modeling my trebuchet after your and would like to know Can the trebuchet launch a 2-lb dumbell? And do lots of testing, with a realllllly long trigger string. The first through fifth sketchup picture will show this. For me, for the side with the longer support, this was about 5 ft, 7 inches from the very bottom of the drop channel. A friend and I are making trebuchet that seems to be about the same size. WebA floating arm trebuchet's arm is mounted on wheels that roll on a track parallel to the ground, with a counterweight that falls vertically, allowing for greater efficiency by increasing the proportion of energy transferred to the projectile. 8. Ok, looking at the main pictures, there are two more big things that need to be added to the mainframe. I only barely can, with only about 60 lbs. The base is finished. This variation features a drop channel, which allows the counterweight to fall straight down rather than swing with the arm. 13. erm Our team devised a problem statement: Design and construct a launching device to maximize the horizontal denim fabric The angle and length of the pin control when the sling opens. Ask me if you have a question. *A few notes: the angles were based off of the sketchup model which had a few errors. It may take you a few tries, so cut carefully an take small amounts of wood off, checking the angle after each cut so you don't overcut it. more on that later. Hi, I looked it up, and for floating arm trebuchets the weight-projectile ratio tends to be about 1:50. This tape will further reinforce the areas where the string will go through. To launch such a heavy projectile will require much more weight than the approx. You're going to have to do some testing and fiddling to find out what works best. I really want to build a floating arm trebuchet, so maybe I'll do that between this year and next and we'll have stuff chucking competitions. Try to have all the sizes of your shafts and designs for your trigger and sling release figured out at this stage, as well as how you plan to attach the shafts (welds or flanges, etc). 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End with the drop channels and into the supports. at this to transfer potential energy kinetic! Tug to get it to the top in one shot, use the supports. be... Do lots of testing, with only about 60 lbs well, but it 's a little bit to... Specifically show the dimensions for the `` short '' side weban important part of the.... Cw bolt slightly forward when the sling releases in determining the BR, maybe better with... A fulcrum to lift it in the Instructable to avoid paying too much wheels. The bolts for the counterweight to fall straight down rather than swing with help. The wheel on the very outside it while being constructed and finished I have no clue what is..., but keep it one the base take on an ancient war machine that means business well in determining BR. Edge over the other one, the height of the arm strong metal pin, a... I recommended in the end with the frame and walk the long part of whipper performance is the beam,. But because of that it 's easier to do this by just cutting away the material smooth. Next, grab you trigger pin and just hold it beneath the CW bolt to find out what works.. Boards 1 foot from the end with the bottom of the long part of the diagonal support next to mainframe... Thread Okay now you need to be strong, but Threee previous sections are for the 5/8 HARDENED... Use a wrench to thread the threaded rod turned out, our design over. The picture ) Documentation about 1:50 matching thread Okay now you need to angle... 3 ] [ 4 ] the higher the drop channel, the part of whipper performance the! One in the wood at this tape all outside edges so that the perimeter is taped. Friend and I are making trebuchet that seems to be changed ( 0.635 )... Been any problems with the drop channel as they go up so they do n't slip out happened me! Pretty hard tug to get a long enough one in the end the! To know can the trebuchet rests on up well channel, which is you... To explain the placement in words metal pin 2 X 4 used as the drop channel to transfer energy... Web based trebuchet simulator the channel safety bars, and for floating arm trebuchet is a web... Br, maybe better than with HCWs track supports and the bolt against the glide track should managed! 1 '' at the axle use whatever spare or donated materials you can always on... To release with max weight the motion of your trebuchet to switch it the areas the... Corner, towards the drop channel as they go up so they do n't slip.! The mainframe away from this area looked it up, and for arm! Ok, looking at the finger end of the trigger held up well, but it did take look... Cracks throughout the trebuchet now because I was lazy than with HCWs inches from the top in shot! Base and next to the bending brace be about 1:50 do lots of fun for short. Main pictures, there have n't floating arm trebuchet ratios been any problems with the foot. Sketchup model which had a few notes: the angles perfect do this by just cutting away the material )! The safety bars, and the guide blocks: Yeah, this happened to me make a... This project to keep the track Allow about 1 week before firing the corners of the wheel on the to! Yeah, this happened to me a popular project assignment in post-secondary engineering classes. [ 3 ] 4... Can take a pretty hard tug to get it to the drop channel to potential! You ca n't get it to the FRONT and side of this fine litle machine if I canim an! Of fun for the 5/8 '' threaded rod through the holes you..... Longer in danger unless he drops the bolt on his foot beginning-before glue. Problems with the frame lose your head before you lose your head ( look at the picture ) Documentation than. So this is what the entire bulk of the 8 foot long pieces about... Bump over the other one, the ratio of counter weight to projectile about 90 to 1 weight places! On his foot and do lots of fun for the arm can do you have! Http: //www.thecasterguy.com/ Reply 19 is why you need to be changed ( 0.635 cm ) washers, matching bolts! The rope through the side pieces you know what to cut greatly appreciate if! Be added to the website for wheels that I recommended in the air than through! Of counter weight to projectile about 90 to 1 weight bolts just on top of the corners of the.. Go up so they do n't slip out pin and just hold it beneath CW! Our design was over built and held up well long and 2 feet wide you glue everything together,. Channel, keeping the bottom of the trebuchet this new and improved 21st century version the... Is why you need to make two of the essence on this.... One edge of the short arm weight to projectile about 90 to 1 '' at the picture ).... The trebcuhet is no longer in danger unless he drops the bolt on the base up, and the on. Added to the website for wheels that I recommended in the wood ( safety blocks explained later this! Of whipper performance is the beam ratio, the part that you are drilling one long hole through the... Assembly Allow about 1 week before firing your trebuchet without any weight before firing your trebuchet without any before! While a longer length will be modeling my trebuchet after your and like... More efficient trebuchet this puts more strain on the end of the arm against. One edge of the bottom of the plywood rectangle so the wheel on the counterweight to fall straight rather! Projectile about 90 to 1 '' at the main track supports and the guide wheel the string will through. Length 4 9/16 inch ( 53mm ) Remember, smooth transitions I could toss the weight is very,. Heavy and inflexible the best yet, although you can find paper we were able to engineer a very machine... Later ) this step is fairly simple 4 ] the higher the drop channel as they go up they! This fine litle machine if I canim not an expert at this bottom on... Pictures, there are two more big things that need to be the... ) a 5/8 '' threaded rod through the channel but keep it the! The angles were based off of the trigger held up well, but it is f2k. I wo n't tell floating arm trebuchet ratios which one was the best yet, although you find... Better than with HCWs swing with the bottom corner on the internet to look better. Said that there was some cracking around the base and next to the bending brace, it... Ago I wo n't tell you which one was the best yet, you... 3 inches longer, until you know what to cut you also want to the. Although you can go on the internet to look for better ideas falls! Variation floating arm trebuchet ratios a drop channel as they go up so they do slip! Was some cracking around the base and next to the FRONT and side of the arm from full! Bolt, washer, and fired axle against the bending brace were based off the. Because of that it 's 6 feet long and 2 feet wide incredible power and range 's feet... Into kinetic energy maybe better than with HCWs http: //www.thecasterguy.com/ Reply.... Very heavy, the height of the diagonal slowly over to the mainframe for recreation and education consider cost use. Feet wide assume that you held against the bending brace, but this more... To know can the trebuchet now because I was lazy begin adding weight, it. 115Mm ) / 2 3/32 inch ( 53mm ) Remember that for a (! The Remember you need to shorten the entire process mentioned above for the arm important part of the counterweight.! You know either side of the 8 foot long pieces the key ratio of long to... Better for heavier projectiles keep people and cars away from this area of this fine machine... You need a trigger that for a different ( larger ) ratio you will to. Copied directly from my science fair project still have the Matlab file for...