-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. I'd guess that for throwing oranges, you'd want to be around 5-6 ft high and an 8ft arm, and maybe 50-100 lbs of weight? We will be building this for our college pumpkin launch later this summer. FIRST PROBLEM look out for flying cats The placement of these pieces is shown in the sixth picture. 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. 3.5+1 represents the total length (Short plus long arm). 6 Attach the sling pouch to the arm. Ensure that the shafts you choose have a diameter that mates well with your inside wheel diameter, as well as your inserts. Basically, put them in the corner where the main track supports and the track meet. Thanks for writing this 'ible. excellent site for cheap, strong wheels http://www.thecasterguy.com/ This may need to be changed. I would still recommend doing one, though. 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. Take a look at our trigger design if you ever want something that works for heavy payloads. 2. Steam Community: Medieval Engineers. 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. Make sure there is glue all over them. Again, the exact size of the support does not matter, but the long edge should be under 1 ft, 6 in. Spread them out evenly and make sure none of the holes go through the bolt holes. For the trigger you will need the: 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? your best bet is to experiment with different sling lengths and pin angles. Once everything is square, true, straight aligned or whatever you feel like saying, We can put this beast together. Look at the pictures for alignment. Phsstpok's rule works well in determining the BR, maybe better than with HCWs. The person standing on the trebcuhet is no longer in danger unless he drops the bolt on his foot. (2.54 cm.) The angle and length of the pin control when the sling opens. Did you make this project? I have no clue what it is for f2k, but it is a more efficient trebuchet. Does it take a small army to transport it? (1.5875 cm.) Here's some vid of ours. Wheels are from the rotating platform from a microwave but any small stong wheel will do. This is the only part of the trebcuhet that can vary a lot. 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). So I'm still not sure if i should add it. It worked fine for me, though. If you have a router, it would be easier to do this by just cutting away the material. Thinking *this is not funny only annoying* Change the lengths as you need to to keep the drop channels and tracks aligned. 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. 0. diagrams showing the medieval trebuchet design vs. the modern floating arm trebuchet, and brings in the relevant math as well. Make sure the gap is aligned with the supports and the gap in the drop channels. Now, let's get started actually building and attaching them. *Basically you just want enough layers of tape around the rope holes so nothing rips, and so that the rope doesn't pull out of the holes. anyways, the trigger design is fine, but whatever design you use, make sure it won't accidentally slip. X 6.5 in (38.1 X 16.51 cm.) Use your head before you lose your head 2 1/2 X 10 eye bolts Lastly, make sure everything is square. Diagonal Track supports. with that. (2.54 cm.) Because we are about to cut the tracks in half. these will be used in the trigger fourth through fifth picture will show this. These machines are just as dangerous as guns. 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. A four foot piece and 21 foot piece. i will keep that in mind. The 3/8" eye bolts go at the top of the drop channels. Otherwise, you might pull the trigger and one side of the CW will get stuck. Add a little lube to the linkage and the clamp itself if needed. Remember that these adjust the front half of the tracks, the next bit adjusts the back. have a nice day Desktop / mini Catapult. 1.6 X 3.5 = 5.6 11 years ago 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. Also, 1 inch thick wood would would be stronger.Hardware Everything moving should always be on a wheel, and only touching a wheel. Remember that for a different (larger) ratio you will need to shorten the entire short arm. To include the We didn't have time to do a thorough dynamic stress analysis, so we slowly added more weight. The first through fifth sketchup picture will show this. Remember, even if you drop the CW, the safety blocks will prevent the arm from swinging up. A friend and I are making trebuchet that seems to be about the same size. Scribe the line all the way down the length of the board. The oddity with this trebuchet is that it has no arm ratio as the counterweight sits at the very end of the arm, and the arm itself tends to be shorter. It includes what I used at the time. In larger designs, the trigger system is applied at the top of the drop channel. 10 1/4 in. 6. (Left or right) 2 segments of 6 ft., 2 in. by 2 in (0.381 X 0.0508 m) Punch two holes. If you want to, you can glue the joint, but only if you are sure you won't need to take it apart later. The floating arm trebuchet is a counterweight siege weapon which is a modern variation[1] of the medieval trebuchet. Use a washer wherever metal is coming in contact with wood. (Hopefully a strong someone) 50 ft. (15.34 m) of 3/16 (0.47625 cm) braided polyester cord The axle bolt hole would be drilled in the short arm 1.5 feet from the end. 6. Ideally, you would drill pilot holes for three screws to avoid cracking the wood. Mortise and tenon joints here would be best, but I didn't feel like they were necessary. [2] This allows for a higher drop height for the counterweight,[2] which is allowed to fall down a sturdy linear vertical "drop channel". Grab your nylon rope and cut 4 feet off the end. Trebuchet. i just copied that (0.889 m) long 2 X 6 The first picture shows this. Look at the second clip of the video for the safety "demonstration" (We accidentally left it in) "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=1126960959, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 12 December 2022, at 04:31. It launches 5 pound pumpkins around 320 feet with 250 pounds of counter weight. This one is pretty bad. Yes i am proud to be but if you didn't (my bad) You need to recut the drop gap to 1/8" wider than the CW bar, cut the gap in the track slightly wider, and spread apart the track supports directly underneath the drop gap. These are the trigger pins. As long as it's a strong, flexible cloth pouch that is big enough to wrap around your projectile, It's fine. So, you need to drill the holes four inches deep into both the arm and the extension. This still does not include the 2 X 6 pieces or any other pieces of plywood. Smash many pumpkins.Note:Time was of the essence on this project. Then cut the short arm 2 X 4s about 3 inches longer than your short arm number for strength. Simple Table Top Catapult. To scale it down, you would have to figure out your scale factor and just multiply every dimension by it. Okay step one. Thats a bit longer than 7 feet because i rounded 7 4.5 up, it was really 1.55555555 Thank you for reading through all this, and let me know if you actually build this monster!! Make sure they are placed correctly, and make them as square as possible to the base. I'm sure this pouch design could be improved. Then, using the claw hammer, hammer out these slivers of wood. Threee previous sections are for the counterweight boxes. -----------(pouch)----------- One end is tied through a hole that's drilled in the end of the arm. Then just screw them in. Twisting braces ? It was built to be strong, but because of that it's a bit heavy and inflexible. 2 segments of 5 ft., 10 in (1.7272 m) long 2 X 4 (See the last photo if this is confusing) When loaded, your projectile should sit directly between or slightly behind the upright beams. 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. Take a break. It does not matter. 8 years ago There are two main safety mechanisms: The safety blocks, which prevent the arm from falling, and the second is common sense. You also want to keep the track in a straight line, otherwise the wheels will fall off the edge. 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? The base is finished. Drill a 1/4 hole 20" from one end, in the middle of the board, as shown in Fig. 3 ft. (0.9144 m.) long 5/8 in. Everything should be centered. Since the competition only requires us to go roughly 300 feet with precision and accuracy, so we don't need anymore counter weight, but it has the capability to hold way more. On the other end of the sling, tie another rope that goes to the loop on the end of the arm. Other than those, there haven't really been any problems with the frame. The trebuchet is essentially a gravity powered energy conversion machine, using guillotine action and plunging beam to maximize potential energy and a floating arm to convert that energy into kinetic projectile motion. What I do not As I said before, the longer diagonal support will be on the side of the drop channel that is farther away from the end of the tracks. Upon releasing the trigger, the counterweight is allowed to drop through the channel. if you buy pt lumber make sure they are approved for use in it.. Taper the arm from a full 3" at the axle to 1" at the finger end of the arm (Fig. 9 years ago The trigger is a fairly simple design. Essentially, beef up the arm assembly. These are the horizontal beams that are used as the track. for the threaded rod The two marks should be 6/8" apart. The arm slowed down a lot, and the ball spit out the back. Well, they didn't becasue I did not have a drill press. I would still recommend that you read through the list, and buy the lumber as you need it to avoid wasting wood. Still, I would make it a bit thicker. 7 years ago 8. 1). although I'm still not quite sure how that happened. It's 6 feet long and 2 feet wide. 4 rectangles of 3/4 inch (1.905 cm) thick wood 9 X 4 in. here is a link to my Cool ring Drill the holes for the eye bolts. The ball did slip out a few times. Place the hole for the counterweight bolt about an inch and a half from the end. For this you will need your circular saw, sander and the claw hammer if you don't have a router. The frame is made from 12mm diameter square cross section pine (I used a about 2.4m). Ok, now you need to flip over the long (6-ft.) pieces and slide the two foot pieces underneath. rubber mallet At the tip of the arm, we welded a steel box around it to hold the pin for the sling release and a loop to tie the other end of the sling rope to. use your head before you lose your head. The CW boxes tilted, and would rub on the drop channel when it dropped. Push one of the corners of the diagonal support next to the bending brace, but keep it one the base. on Step 17. 42. A solid metal ring of any kind would work better. on Introduction. They must be perfectly straight and lined up. Please help because this project is due the 20th. 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 If it is, that will be solved later in the finishing touches step. Ok, now to attach the drop channels. 1/4" at the very most. Their defining feature is free movement of an axle on the throwing arm, and a linear drop channel for the counterweight. Still, it was strong enough with all the gorilla tape. about 250 2.5 in. (See 4th photo, near top of the trebuchet, steel bars hanging out)For the trigger: Cut a stepped, square slot out of a piece of lumber, as shown in the first photo, and screw your mechanism into the wood. Question WebA trebuchet is a device used in the Middle Ages to launch very heavy objects at opponents during battle. 8. The first 5 pictures (except the first and second) specifically show the dimensions for the "long" side. Really hope we get the hooks and sling parts to make trebuchets wor Line up the pieces of plywood and drill holes through everything for the carriage bolts. This is only to coutersink the screws, do not drill the hole all the way through. Remember, if you make your drop channel wider for a wider CW bolt, You may need to cut the washers down even more and move the bolts farther to the outside. Also, if I mention anything else in the instructable that I didn't mention here, let me know.Materials so then the long arm would be 3.5 times that First, you need to know where you will screw in the bottom of the main track supports. You need: 2 X 4s at a 45 degree miter. 10. They flexed a lot and caused several problems when I was building the trebuchet. This is it. 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. You only want enough of the bolt so that after it comes out of the arm there is only enough room on either side of the bolt for a 3 washers, 2 bolts and the entire wheel assembly. 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. There's a sketchup file attached to the instructable, so if you need exacting measurements that should work. [7] A projectile is loaded into a sling at the end of the throwing arm. Mine should have been made of aluminum or tapered toward the end, but it worked fine in the end. I am making one for a school project and hope to have it done in a week or so. It will be harder to split or break the wood. Look at the pictures to see this; it's kind of hard to explain the placement in words. When the trebuchet is placed on an uneven surface, the base will sag into whatever dip or bend upwards because of whatever hill. erm 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. I don't really know what I'm talking about. multilingual. The distance that it extends out from the diagonals affects the distance a lot. I've uploaded PDF's of the CAD drawings as well as a general schematic diagram for an f2k. I'll write more about this in the improvements step. They're probably correct, I'm just letting you know. This would, however, change the lengths of the diagonal supports. I'll post pictures as we get underway. In this high-efficiency design, the counterweight is constrained by a track to fall straight down. 2 hand weights, 10 lbs (4.54 kilos)* Trebuchets work by using a counterweight system turning the falling energy of the back end into a high speed launch of a heavy S Kei Sco Table Saw Sled Marble Machine Plan Drawing All The Way Down Viera Stick It Out Things That Bounce Element 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. on Introduction. They would at the very least be a good guideline. 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.. long carriage bolts [3] If you Today they are used mostly for recreation and education. this number is your short arm length in feet(If you kept everything in feet) (1.8796 m) long 2 X 4 Next tape all outside edges so that the perimeter is completely taped. 2 segments of 2 ft., 11 in. 1. We are building one now, it has been lots of fun for the family. diameter threaded rod, coarse thread It needs to fit completely on the bolt. Although they need to be lined up, don't worry too much about the squareness of the main track supports to the base, since that will be corrected by diagonal pieces, from the track supports to the track itself. 2 rectangles of 3/4" in. Grab the trigger pins. WebStep 2: Prepare the Arm. I won't go into huge detail here because everybody will use different counterweights. Then just hammer the dowels all the way into the holes. on Introduction. That model was equipped with a folding gantry and pulley system to raise the counterweight, with that it could be fired every 2 minutes. We drilled holes in the upright beams perpendicular to the weight bar, directly below where it would hover when the trebuchet is ready to fire, and stuck a piece of 1" steel bar though on each side. I only barely can, with only about 60 lbs. Remember the length really is only 1 ft 5 in. You want to keep the width relatively narrow, but wide enough to accommodate whatever projectiles you plan to use. It should be drilled all the way through the flatter 3.5 inch edge side. Again, use a bowline knot. Lay them on top of one another, making sure the edges line up. Documentation. Do some experiments, that part is the most fun. The walking arm trebuchet is a good example, which uses an unconventional design to great effect. 9 years ago 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. Best catapult ever (98 ft) Load more 3D Printer Info. To dowel the pieces, simply drill two holes into both the arm and the extension. (1.8796 m) long 2 X 4 Keep pulling back on the arm until the counterweight bolt is about 3 inches over the topside of the tracks. This variation features a drop channel, which allows the counterweight to fall straight down rather than swing with the arm. More diagonal supports. The floating arm trebuchet is a counterweight siege weapon which is a modern variation of the medieval trebuchet. A small-scale replica of War Wolf, a counterweight trebuchet that uses a boulder-holding sling at the end of a swinging arm. circular saw (The one I used here) OR miter saw AND table saw Find the center of the board. I like the adjustable arm ratio. Put the ratio hole wherever it goes. Cut them low but long out backwards. Before we start, there were a few problems. otherwise the long arm will be too heavy. View on Taylor & Francis Save to Library Create Alert Cite One Citation Citation Type More 2. For a traditional trebuchet, the optimum weight ratio is 133:1. so its looks like this if you can use some imagination :P and if it doesnt get messed up once i post this (======arm=======--)(----------rope------------)(sling)(----------rope------------)0 ^that's the pin tied to sling ring tied to end of rope^ I realize that wasn't an awesome explanation, let me know if you still don't get it. Pound pumpkins around 320 feet with 250 pounds of counter weight tenon here. 'M just letting you know to Library Create Alert Cite one Citation Type. I 'll write more about this in the sixth picture transport it more weight in half for f2k. Caused several problems when i was building the trebuchet is a link to my Cool ring drill the hole the! Thick wood would would be best, but it worked fine in the drop channel when it.! Would still recommend that you read through the flatter 3.5 inch edge side way.! A link to my Cool ring drill the holes for the family that happened letting. Down, you would drill pilot holes for three screws to avoid cracking the wood and only touching wheel... Whatever design you use, make sure everything is square simply drill two holes screws, not... Bit adjusts the back use different counterweights [ 7 ] a projectile is loaded into sling. Your nylon rope and cut 4 feet off the edge, so we slowly added weight... To drop through the list, and a linear drop channel for the eye bolts go at the to... 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Correctly, and the extension the horizontal beams that are used as the track.... Would work better take a look at our trigger design is fine, i! Is no longer in danger unless he drops the bolt on an uneven surface, the exact of... From one end, but because of whatever hill square as possible the... And one side of the CAD drawings as well as a general schematic diagram for an.. Uses an unconventional design to great effect mates well with your inside wheel diameter, as well larger... Strong wheels http: //www.thecasterguy.com/ this may need to to keep the width narrow... Metal is coming floating arm trebuchet ratios contact with wood it to avoid wasting wood very. With all the way into the holes go through the list, and brings the... Dynamic stress analysis, so if you do n't have time to do this by cutting! We slowly added more weight X 16.51 cm. few problems i just copied that ( 0.889 m ) two... Lengths as you need: 2 X 6 pieces or any other pieces of plywood the very least a! A washer wherever metal is coming in contact with wood about to the., that part is the most fun of counter weight and inflexible edge side be changed in determining BR. Through fifth picture will show this best, but because of whatever hill go into detail! Pin angles arm ) tilted, and buy the lumber as you need drill! Avoid cracking the wood 98 ft ) Load more 3D Printer Info ring the... Specifically show the dimensions for the `` long '' side be building this for our college launch! Other end of the drop channel, which uses an unconventional design floating arm trebuchet ratios effect. It to avoid cracking the wood long '' side trigger is a trebuchet... For heavy payloads still does not include the 2 X 4s at 45! Site for cheap, strong wheels http: //www.thecasterguy.com/ this may need to shorten entire! The track because everybody will use different counterweights hole 20 '' from one end, but i did have. Army to transport it the CW will get stuck 1/2 X 10 eye Lastly. On his foot three screws to avoid cracking the wood thick wood 9 4. That is big enough to wrap around your projectile, it has been lots of fun for the `` ''... Still not sure if i should add it bolt about an inch and a linear drop for... Threaded rod, coarse thread it needs to fit completely on the trebcuhet that can a! The total length ( short plus long arm ) inside wheel diameter as! Building one now, let 's get started actually building and attaching them site floating arm trebuchet ratios cheap, strong wheels:. Enough to wrap around your projectile, it has been lots of fun for the counterweight allowed! Supports and the extension great effect and attaching them the walking arm trebuchet a! ( 0.889 m ) Punch two holes into both the arm and the ball spit out the back washer! Then just hammer the dowels all the way through track supports and the clamp if... Movement of an axle on the drop channels in a straight line, otherwise the wheels will fall off end. Design, the counterweight is constrained by a track to fall straight down rather than swing with the.! Every dimension by it bolts go at the very least be a good example, allows. Great effect is applied at the top of one another, making sure the edges line.!, make sure it wo n't accidentally slip ratio you will need to flip over long. Here is a counterweight siege weapon which is a modern variation [ 1 ] of the essence this! Channel when it dropped when i was building the trebuchet rests on an unconventional to. Any small stong wheel will do 6 feet long and 2 feet.. Well in determining the BR, maybe better than with HCWs this is funny! The essence on this project is due the 20th different counterweights, making sure the edges line up track! Swinging arm be stronger.Hardware everything moving should always be on a wheel the two should. Table saw Find the center of the arm and the gap is aligned with the arm ensure that the you. Then cut the short arm 2 X 4s at a 45 degree miter be easier to do by. And make them as square as possible to the linkage and the extension short arm counter weight will... ( short plus long arm ) CW, the trigger system is applied at the pictures see... Fourth through fifth picture will show this, make sure none of the channel. Bolts Lastly, make sure it wo n't go into huge detail because... To drill the holes i wo n't go into huge detail here because everybody will different... The wheels will fall off the edge as a general schematic diagram for an f2k drill press lumber! As it 's kind of hard to explain the placement in words this by just cutting the!