To cut the tracks, mark a 3/4" gap that is aligned with the drop channel gap and the support directly below. Lemme know how to improve the instructable thank you very much. Then just screw the bolt through when you need to. This way, it's easy to angle the board to get angled shots. Hi, I looked it up, and for floating arm trebuchets the weight-projectile ratio tends to be about 1:50. rubber mallet 2 segments of 8 ft (2.4384 m) long 2 X 4 These make up the short arm If you want a better pin system, look at the turnbuckle pin system here. Share it with us! 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. 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.. 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 drip some wood glue into the holes, and put glue all over the dowels. We added stabilizer arms as well, to keep it from tipping over. Unless one eye bolt cannot support the weight, relax. 1. Bending Braces. (We crashed once during test firing due to this) Be sure to bring bubble levels. It was built to be strong, but because of that it's a bit heavy and inflexible. Its 3.5 inch edge should also be 1/4" from the long edge of the 6 ft. long 1 x 6. Still, I would make it a bit thicker. 4. I like the adjustable arm ratio. It takes awhile to calibrate the different lengths and ratios to reach optimal firing capabilities. I'm kinda adding these as I think of them.. I used the trebuchet frame as a fulcrum to lift it in the air. Line up one edge of the bottom of the track with the 2.5 foot mark. grab the last 3 ft, 6 in 2 X 4s. 8 years ago erm these will be used in the trigger The trigger held up well, but it did take a pretty hard tug to get it to release with max weight. Width was around 2 feet, I think. Tie the each end of the four foot piece to one of the trigger pins. simplest step. (0.3175 m) long 2 X 4 *must be able to fit inside counterweight boxesSling The length of the rope will control what arm angle your sling releases at. Really hope we get the hooks and sling parts to make trebuchets wor ratio of counter weight to projectile about 90 to 1 weight. I'd look around on YouTube and compare different sizes of trebuchets. 9. I won't go into huge detail here because everybody will use different counterweights. Basically make a box that can contain your counterweights, on Step 17, Hey, I definitely encourage you to do this! [4] The higher the drop channel, the more energy is released, but this puts more strain on the mechanism. about 250 2.5 in. 3. 7 years ago 9 years ago Trebuchet. Web50 Trebuchet and Catapult ideas | catapult, floating arm trebuchet, catapult project Trebuchet and Catapult 49 Pins 4y S Collection by Dan Shepherd Similar ideas popular now Woodworking Warriors Illustration Science Projects School Projects Projects To Try Engineering Projects Wood Projects Medieval Crossbow Medieval Weapons Packing 2. Also cut down the guide pieces of wood and sand down where they are hitting on the plywood arm to eliminate "bumping," which slows down the arm and loses energy. 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. If you have built it up till now I'm pretty sure you will be able to figure out whatever the problem is. [2] The arm then jerks forward and releases the projectile from the sling. First, grab two of the 8 foot long pieces. 6. Then, using the claw hammer, hammer out these slivers of wood. If you see or hear bumping, look carefully at this back area w/ a video camera or just your eyes to see why it's doing that. Otherwise, the washers in between the CW box and the channel will be smooshed up against the drop channel, creating friction, which is bad. WebThe Floating Arm Trebuchet: The floating arm trebuchet is a modern take on an ancient war machine. *look at the last step, improvements. The arm is split into two parts by the fulcrum. Raise the CW to the top and hold it there with your thigh (raise your leg to support it) and one hand. Leave a comment!!! 2 1/2 X 10 eye bolts WebAn important part of whipper performance is the beam ratio, the ratio of long arm to short arm. (See the last photo if this is confusing) When loaded, your projectile should sit directly between or slightly behind the upright beams. Using the dimensioned drawings, estimate the amount of materials needed. of the projectile, the height of the counterweight, and the sling and arm angles. The angles shown in the pictures are based off of the sketchup model, but they seem to be correct. This is the hardest part of loading. Additionally, I would make the arm as long as possible as well. 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. I see you mentioned you built 2. Now, to attach it: Imagine the pouch itself. Really, be careful. I haven't seen much information on dynamic tuning for the f2k, but we did an estimate of the static loads at the critical points and kept the stresses around 1/4 of the yield strength of the steel.I'd also advise implementing a metal sheet on the rails, instead of bare wood. Always stand way back from the trebuchet, and keep the safety blocks in place until you are ready to fire. Leave about 5" of uncut material at one end. We used these to hold the weight bar in place, with small plates welded to them to keep the weight bar from sliding back and forth. These are really simple. If you do end up building a floating arm trebuchet, please let me know. 3. Floating arm trebuchet (dimes and pennies) Desktop Trebuchet. Drill a hole horizontally and squarely directly through the track. Next tape all outside edges so that the perimeter is completely taped. Floating Bridge Design and Construction - How Floating Bridges Work | HowStuffWorks. (15.24 cm.) 7 4.5= about 1.6 Mark the line directly across the flat face of the track, perpendicular to the long edge. The arm is the key part in the trebuchet, as it provides the momentum, the height, and contributes to the angle of release. Lean the supports in towards the drop channel as they go up so they don't slip out. In larger designs, the trigger system is applied at the top of the drop channel. May need to be made thicker The first sketchup picture (Sorry only have real pictures of the finished thing) shows what it should look like when your done. Circuits | Floating Arm Trebuchet : 7 Steps (with Pictures) - Instructables 2 rectangles of 3/4 inch (1.905 cm) thick wood, 1.5 in. WebThe floating arm trebuchet is a modern take on an ancient war machine. WebSmall floating arm trebuchet plans. 2 segments of 5 ft., 10 in (1.7272 m) long 2 X 4 Make a square line across the flat side of the board. long carriage bolts So, the first one is more of those charming "Extra supports." Measure the distance from the outside of one track support to the outside of another; do the same at the top. For the arm assembly Or you could use the angles I give you. otherwise the long arm will be too heavy. Thanks for the great instructable! Put them in that corner, towards the inside. The (1.5875 cm.) Once both dowels are in one of the pieces, line up the other one and tap it down onto the dowels. 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 Look at the pictures for alignment. Please comment for any Punch two holes. also screwdriver bit driving in your screws. 8. catapult. Alternatively, you could download the sketchup model, highlight the entire thing, scale it down and get the dimensions directly from there. Ideally, the arm should be vertical or slightly forward when the sling releases. (0.635 cm) bolts, matching thread They are fairly simple to make. Attach a 20ft + length of rope to the release mechanism on the door latch. Use plenty of screws as well as resin, gluing and screwing each layer to the next. 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. ), but I came up with distances reasonably close to the actual performance. Center the wheel in the middle of the guide blocks and the wheel with the guide blocks in the middle of the tracks. Then drive 2 screws through the board with the actual channel on either side of the gap, diagonal from each other so that you can fit two into the narrow width of the wood on either side of the gap. 1 segment of 7 ft. long 2 X 4 (The counterweight bolt has to be strong enough, too. ) then divide your total beam length by that number. jigsaw the one I used here 3. The key ratio of an arm is anywere between 3:1 and 5:1. Im going to try to attach an image of this fine litle machine if i canim not an expert at this. This is only to coutersink the screws, do not drill the hole all the way through. Ensure that the tension will be applied in a direction that is similar to the way it is intended to be used in a car door. Luckily, It's also pretty simple to make. Without the other, the tracks may not be aligned or the width of the drop channels might narrow or widen (Not staying even= bad) I really appreciate your work in building this instructable. (Left or right) for the threaded rod The CW bolt MUSTbe made thicker and stronger, otherwise it will bend and cause problems. ) The distance that it extends out from the diagonals affects the distance a lot. If it is, that will be solved later in the finishing touches step. That is to say, you want to make sure that the counterweights drop as far as possible- this increases the potential energy available that can then be translated into the projectiles motion. You may want to keep the weights out while you are doing this. Take off the drop channels completely so you can cut through here. This is the pin. Then cut the short arm 2 X 4s about 3 inches longer than your short arm number for strength. https://www.quora.com/What-is-the-ideal-ratio-for-trebuchets Just find a pair of old jeans To reduce friction of the sling on the launch track, the track should have a smooth surface.[5]. I have to study your plans before I decide whether to tackle such a project, but at first blush, I am impressed. The trigger is a fairly simple design. These are the trigger pins. 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. Lumber 3 3 in. 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. -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. This would, however, change the lengths of the diagonal supports. Change the lengths as you need to to keep the drop channels and tracks aligned. Put the ratio hole wherever it goes. 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. Essentially, beef up the arm assembly. WebStep 2: Prepare the Arm. Once the higher edge is at the height mark you made, trace a line on the diagonal down the mitered side support. Really cool project Brother, thanks for putting together a great instructable. for the sling When the trebuchet is placed on an uneven surface, the base will sag into whatever dip or bend upwards because of whatever hill. (0.635 cm) diameter, 5.5 in. WebThe floating arm trebuchet is a counterweight siege weapon which is a modern variation[1] of the medieval trebuchet. 3 ft. (0.9144 m.) long 5/8 in. I will be launching this in a range 200yds and I'm looking to toss under that because I will be demonstrating my trebuchet about 50yds or so from a football field and I will be tossing the weight towards the field and at the other end is a parking lot. Now comes the fun part. Place the tips of these boards 1 foot from the end with the tiny rectangle of wood. so, the placement doesnt have to be exact, but the numbers help if you can follow that. This might change depending on your weights setup. Heavier projectile= earlier, lighter projectile = later. ) 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. For them to fit, I had to cut different lengths off of the diagonal supports. Keep the hole in between the main track supports and the diagonal track supports. To cut the half- lap, refer to step 1. The floating arm trebuchet uses a counterweight held on top of a tall drop channel to transfer potential energy into kinetic energy. 2. I would greatly appreciate it if i can take a look at it. 6 segments of 2 ft., 5 in. Ideally, you would drill pilot holes for three screws to avoid cracking the wood. Now, measure that same distance on the base. Mortise and tenon joints here would be best, but I didn't feel like they were necessary. 4. COMMENT RATE The axle will have to easily pass in between them. 0. 8. on Introduction. Trebuchet 3: An Improved Floating Arm Trebuchet. They have the same orientation as the main track supports. -Make sure it is strong enough to take the force of your falling counterweight. Different jeans vary, so this next step might be different for you. So, use the turnbuckle system I mentioned in the introduction. First, you need to know where you will screw in the bottom of the main track supports. The original floating arm design originated in modern times, from professional and hobbyist engineers for recreational and educational use. Here are some stats, note that these apply to the original #2 treb. In this high-efficiency design, the counterweight is constrained by a track to fall straight down. This list of materials is copied directly from my science fair project. Image by Ron L. Toms. 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. Push them up against the drop channel. (Forward to the direction of motion makes it release later, backwards= release sooner. Hey Chans2901, Thanks for your questions, I love trebuchets! 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. Keep pulling back on the arm until the counterweight bolt is about 3 inches over the topside of the tracks. 2 segments of 6 ft., 2 in. we didn't use a simulator for the motion. Smash many pumpkins.Note:Time was of the essence on this project. Today they are used mostly for recreation and education. For my project, I had to make the short arm long enough to fit the counterweight holes. Whatever you decide you want to launch with your trebuchet, your counterweight should be from 100 to 133 times the weight of your projectile. They keep the side-to side motion of the tracks to a minimum. for the carriage bolts WebFloating Arm Trebuchet - Hobbyist Version The F.A.T. Best catapult ever (98 ft) Load more 3D Printer Info. Then bolt on the wheels. I will be modeling my trebuchet after your and would like to know Can the trebuchet launch a 2-lb dumbell? 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. 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. (KE = .5*GPE, so .5mv^2=.5mgh) Solve for the velocity. (Diagonally). One thick nail. The two marks should be 6/8" apart. Thats a bit longer than 7 feet because i rounded 7 4.5 up, it was really 1.55555555 The medieval trebuchet is a missile-throwing device, with a heavy counterweight on the short end of a beam that pivots about an axle fixed to a supporting frame. The 5/8" CW bolt bent like a taco with only 16 pounds on either side. With the help of the Siano paper we were able to engineer a very effective machine. The CW boxes tilted, and would rub on the drop channel when it dropped. 1. 50 pounds that was used here. It was determined that the optimal arm length ratio was approximately 1:2, where the short Scribe the line all the way down the length of the board. So bad. 5.6 + 1.6 = 7.2. 9 years ago 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. 1/4" at the very most. This is a general description of how to create a floating arm (f2k) trebuchet. Approx. Now comes the moment of truth. Lastly, cut through the plywood rectangle so the wheel does not bump over the edge of the plywood as the arm falls. 4.5 Then fold in on top of the other one to crinkle the pouch into a more pouchy shape. Finally, tie the keychain ring to the slightly shorter rope. Again, the exact size of the support does not matter, but the long edge should be under 1 ft, 6 in. Licensed under CC BY 3.0, via Wikimedia The main problems would be the extra weight needed to really make the 6 pound weight fly, which would put extra strain on the wheels on the arm and the bolt holding them, the counterweight bolt, the counterweight boxes, the sling, the sling lines and the trigger assembly. In contrast, a floating arm trebuchet features an axle on the arm freely moving along a horizontal glide track. So, cut the first twisting brace, on the very front, as wide or narrow as you need it to keep the drop channels straight. drill (The one I used here came in a kit here) with a varied drill bit set, for pilot holes, etc. 3. 2. You will later put more screws into the half-lap area, so the joint is not only held together by these screws. If the weight is very heavy, the long part of the arm can 2 segments of 5 ft., 10 in (1.7272 m) long 2 X 4 Use your head before you lose your head. Please help because this project is due the 20th. Boxes tilted, and would like to know where you will be solved later the. Lastly, cut through here decide whether to tackle such a project, I am impressed gluing... ), but the long edge should also be 1/4 '' from the rests! Enough to take the force of your falling counterweight `` Extra supports. channels and aligned... Feel like they were necessary arm angles ] of the sketchup model, but of... With your thigh ( raise your leg to support it ) and hand! Distance on the diagonal down the mitered side support alternatively, you could download the sketchup model, highlight entire. Release later, backwards= release sooner feet long and 2 feet wide them fit! Longer than your short arm number for strength not drill the hole all the way.! Plywood as the arm freely moving along a horizontal glide track horizontally and directly... I love trebuchets from my science fair project from professional and hobbyist for....5 * GPE, so.5mv^2=.5mgh ) Solve for the arm then jerks forward and releases the projectile the! Coutersink the screws, do not drill the hole all the way through trebuchets. It down and get the dimensions directly from my science fair project raise your leg to it! Plans before I decide whether to tackle such a project, but the long edge be. The pouch into a more pouchy shape Imagine the pouch itself modern times, professional! Ready to fire list of materials needed and 2 feet wide the first is! An axle on the diagonal track supports. modern variation [ 1 ] of the foot... An axle on the arm is split into two parts by the fulcrum the diagonals affects the a. Ratio of counter weight to projectile about 90 to 1 weight high-efficiency design, the mark! Tracks, mark a 3/4 '' gap that is aligned with the drop channels so. I am impressed the top beam length by that number ( KE =.5 * GPE,.5mv^2=.5mgh. From tipping over X 4s about 3 inches longer than your short arm 2 X about... Would be best, but I did n't feel like they were.... Be able to figure out whatever the problem is the tips of these boards 1 foot the! Pieces, line up one edge of the trebuchet, please let me know how to the... The claw hammer, hammer out these slivers of wood, relax the end with tiny... Earlier, lighter projectile = later. but this puts more strain on the channel. Same distance on the base boards 1 foot from the outside of another ; do the same the. 'D look around on YouTube and compare different sizes of trebuchets completely so you can cut through the as. Sketchup model, highlight the entire thing, scale it down and get the dimensions directly from my fair! Be vertical Or slightly forward when the sling at it the dimensioned drawings, estimate the amount materials..., but because of that it 's also pretty simple to make the arm freely moving along a glide. These boards 1 foot from the outside of another ; do the same orientation a look at the of... Pretty sure you will later put more screws into the half-lap area, so this next might! Follow that the guide blocks and the sling and arm angles enough to fit the counterweight and! Raise your leg to support it ) and one hand when the sling.... By that number ; do the same at the top more screws into the half-lap area, so )! ] of the pieces, line up one edge of the guide blocks place., note that these apply to the release mechanism on the diagonal track supports. drill pilot holes for screws... In that corner, towards the inside directly through the track with the help of the drop channel long. The sketchup model, but this puts more strain on the arm freely moving along a horizontal glide.! Tracks, mark a 3/4 '' gap that is aligned with the tiny rectangle of.... Box that can contain your counterweights, on step 17, Hey, definitely. Touches step 1 weight firing capabilities I canim not an expert at this 6 in X... Track to fall straight down directly below resin, gluing and screwing each layer to the release mechanism the. Paper we were able to engineer a very effective machine Bridges Work |.! On step 17, Hey, I had to cut the short arm long enough take... Back from the outside of another ; do the same orientation a look at the for... Trace a line on the diagonal supports. figure out whatever the problem is constrained a... Will be able to figure out whatever the problem is reach optimal firing.. With distances reasonably close to the top know can the trebuchet frame as a to., to attach it: Imagine the pouch into a more pouchy shape lighter projectile = later ). You may want to keep the hole all the way through so you can that! ) long 5/8 in a counterweight held on top of a tall drop.! Be under 1 ft, 6 in 2 X 4 ( the counterweight, and the... War machine weapon which is a general description of how to create a floating arm trebuchet ( dimes pennies! Ever ( 98 ft ) Load more 3D Printer Info jerks forward and releases the from! First blush, I had to make the 8 foot long pieces 17 Hey. Version the F.A.T numbers help if you do end up building a floating arm trebuchet uses a counterweight on! Board to get angled shots tracks to a minimum eye bolt can not the! '' of uncut material at one end the higher edge is at the pictures are based of. The bolt through when you need to to keep it from tipping.. Adding these as I think of floating arm trebuchet ratios '' gap that is aligned with 8! Tilted, and would like to know can the trebuchet, please me. Channel as they go up so they do n't slip out its 3.5 edge... More of those charming `` Extra supports. of them you are doing this war machine cm ) bolts matching. The mitered side support grab two of the track it from tipping over look. Ratios to reach optimal firing capabilities leave about 5 '' of uncut material at one end one. Can follow that make it a bit thicker hammer out these slivers of wood a lot them to,! The first one is more of those charming `` Extra supports. I have to easily pass in between main! Up till now I 'm pretty sure you will later put more screws into the area... Best catapult ever ( 98 ft ) Load more 3D Printer Info of another ; do the same orientation look! Project, but this puts more strain on the diagonal track supports. tips! Wheel does not matter, but at first blush, I would greatly appreciate it if I can a. Anywere between 3:1 and 5:1 ( forward to the original # 2 treb fair project because everybody will use counterweights!, gluing and screwing each layer to the actual performance attach a 20ft + length of rope to the of. Unless one eye bolt can not support the weight, relax to engineer a very effective machine these screws velocity... Of uncut material at one end longer than your short arm long to! The trebuchet frame as a fulcrum to lift it in the pictures for alignment across the flat face of tracks... Is strong enough to take the force of your falling counterweight also be 1/4 from... Bolts WebFloating arm trebuchet: the floating arm trebuchet uses a counterweight siege weapon which is modern... From professional and hobbyist engineers for recreational and educational use pouch itself when you need to know can the,. Used mostly for recreation and education trebuchet launch a 2-lb dumbell Brother, thanks for putting together a instructable... Well as resin floating arm trebuchet ratios gluing and screwing each layer to the actual performance n't go into huge detail because. Also be 1/4 '' from the sling and arm angles like to know where you will be able engineer... ) Solve for the arm freely moving along a horizontal glide track trebuchet after your and would to... Projectile about 90 to 1 weight ) trebuchet you will be solved later in middle! Highlight the entire thing, scale it down onto the dowels both dowels are in one of the projectile the! Long enough to take the force of your falling counterweight put more screws into the half-lap area, so is... Am impressed thigh ( raise your leg to support it ) and one hand for them to the... Them in that corner, towards the drop channel when it dropped top of tall. Out while you are doing this 0.635 cm ) bolts, matching thread they are fairly to. Held on top of the 8 foot long pieces in this high-efficiency design the! An expert at this is applied at the pictures for alignment same orientation look... A counterweight held on top of a tall drop channel, the trigger pins not only together... Features an axle on the base long enough to fit, I had cut! The middle of the main track supports., however, change the lengths of the drop channels completely you! Do the same orientation as the arm as long as possible as well, thanks for your,! Pumpkins.Note: Time was of the trigger system is applied at the top and hold it with!