Tennis Ball Trebuchet [how to make]
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- เผยแพร่เมื่อ 28 ม.ค. 2019
- This is a full on how to make video of a Trebuchet to throw tennis balls. Complete with stills of the plans so you can screen capture or pause the video and make a drawing of them.
It did not throw as far as I wanted but it was fun to make and the dogs are starting to get the hang of it throwing stuff (first few times the sound scared them LOL)
Feel free to post your questions and be sure to read the comments for questions that have already been answered.
I plan of doing more medieval siege engines in the future so you may want to subscribe as well so you will catch them when they come up.
Contact Uncle Cy at Cythedrumguy@gmail.com
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fav part is easily the trap beat over the vid lmao
That's cool design my friend. My son is building one for a school project, thank you.
super cool design build. really good A/V production too. thanks!
Glad you like it!
thank you for making this video. now I can work on my woodshop project
Very interesting! Dogs have fun!
My granddaughter and I built a trebuchet a few years ago to throw a 8" pumpkin 300 feet. She won first place for her science class.
How heavy was the counterweight
That is amazing man. Wish my granddad would have done stuff like that with me.
Hi, I would be interested to talk with you. If you see this, please reply
uncle Cy with the beats
Didn't expect to be bobbing my head to a trebuchet build lol
Love the vid, Cy - aimed at my level. Mick in York, UK salutes you.
I think the sling on the trebuchet is too long. The length from the end of the cord to the center of the pouch should be about the same length as the long side of the arm, but right now it is longer.
this
I read the same thing.
The length of the sling should be no further than the arm to the pivot point.
And if you're designing a trebuchet the pivot point on the arm is at a distance ratio of 3.75/1 ...
Yep!! I left a similar comment just now, I’m doing a school project investigating the long arm to short arm ratio and how it affects launching speed. When building the first prototype I could for the life of me get it to throw properly as the sling just falls limp towards the end of the motion. My sling was too long by about 10% the length of the long arm. Immediately fixed when reducing the sling length. I wonder whether this has more to do with angular velocity and centripetal force or the fact that a longer sling means more mass in the rope and therefore more mass needed to keeep the rope in tension?
What a nicely easier build than another TH-camr's. I can do steps of wood and make holes to bolt the pieces together!
So uh...not only thank you for the video, but the music choose had me blown away lmao.
i was thinking same thing
Choice
Awesome idea
Thanks so much for teaching me!
Sir - you are my hero
Hay uncle cy went back and watched your chainsaw unboxing video's decided on the g660. Really good video's
I enjoy watching them. Looks like you enjoy building stuff as much as I do .
Elliot Duncan This whole comment is a grammar nazi’s nightmare
Thanks for posting this!
Since the counterweight is kinda hinged, could you flip it up on top of the arm so it falls further?
Yep that would work, however I’d be worried that the torque created as it flips into the normal position would be quite high…
@@er4din903 this was a comment from 2 years ago, building with my son.
I think we had a pretty efficient set-up, since there was little to no motion after that ball is flung.
th-cam.com/video/YOC64pVdgcE/w-d-xo.html
Awesome little machine I think part of the problem with the not throwing the tennis balls as far as it should I think the pouch the folds in the pouch maybe holding the ball back some I would turn the pouch inside out maybe or just make one out of leather no folds again awesome little machine
What do you suggest on the sling ? What type of the string you used? Or it does not matter
Interesting, thank you.
Try putting wheels on it. The rocking motion will give it the extra oomph you need for distance.
Thank you for posting. If you slow down the video you can see the counter weight stops the arm motion very short. All the videos I watch that were a bit more successful the counter weight would swing farther. Maybe there's something to that, that needs to happen?
Love the design and scale for this, my sons immediately asked to build one for our dog. Just one question, how much more weight can this size handle? I'd like to keep the same scale but double the weight... Thank you for the walk through and posting your prints!
According to a university study by Donald B. Siano, the optimal weight depends on the mass of the projectile being thrown, however the optimal ratio is aproximately 1 to 133, in other words, if the projectile weighs 10 grams then the counterweight must weight 1330 gramms, im afraid I do not know how to convert to imperial but that hardly matter since what is important is the ratio. I suggest you weight your projectile, calculate optimal counterweight mass then scale your trebuchet according to how much force it must withstand. A tennis ball weighs around 60 gramms from what I seem to remember so the counterweight should weight around 8 kilograms.
Nice !! Lets build one for that constantly annoying Walmart commercial & their 20 lbs of Watermelons.
You are awesome
Great project Cy Pups like it & That's what counts ! ATB T God Bless
Is it matter to use one string to pull the pouch or two strings ? Not sure why the ball already being threw out of the pouch during the halfway of pulling the string or gone to backward, the tennis ball not being threw in front of the direction
Just stumbled across your video/channel and heard you mention you’re from Mo! What part? I’m in St.Charles...great video...I’m building one about 1/3 this size for my desk. Can’t wait to lay siege to my coworker’s desk..
I'm in the KC area. Long ago I built one with a 160lb counterweight and an 8ft arm. It would throw apples 500 ft.
If they don't bring the ball back, how are they requiring you to throw it all day?
thank you for posting this and making my physics proyect like a bagilion times easier
God help us all.....
@@shawnhuk ??
@@troliskimosko I don't remember why I wrote this 🤷
Wheels, the straighter up and down the weight travels the further the projectile will go. The treb. Needs to move forward and backwards.
no cap I am actually going to build this for a school project
dsame LOL
Minor advice from a student who did just that, check out the paper written by Donald B Siano called Trebuchet Mechanics.
It’s long but you don’t need to understand all of it, just the conclusions. It’s a really good source to take optimal ratios from for your control variables and very convenient to cite from. Also, I recomend that if you’re doing this for a study of some sort, don’t investigate the launch distance since that is wildly uncontrollable due to often inconsistent launch angles and trajectories. Instead find a way to calculate launch velocity, a good way to do that is to slow mo record you launches against a 10cm tiled background ( white board divided in 10 cm grid placed in the background of the trebuchet while the camera records from the side) and measure distance travelled divided by the number of frames and incorporate frame rate to get meters per second.
As far as building the thing goes, make sure you have a good sling pouch, there are many ways to make one and it’s hard to say which one is best, but I’d generally advise against using very soft materials like thin fabric opting instead to use something durable and tougher.
Also a very insidious problem that can arise that can affect results drastically is the fact that the sling shouldn’t be longer than the long arm of the trebuchet, equal is best but not longer. Try to minimize friction at the axle, metal axle works best, if you can find an aluminum smooth rod and a bigger one with a cavity inside it just big enough to slide the other one into you got yourself a fantastic pivot, just add some wd-40 and you’re laughing.
I could list more optimal ratios but the can almost all be found in Donald B Siano’s paper so check it out.
Could you post the 3D model and also maybe like a blueprint please?
Did uncle Cy post the blueprint? And where did he?
A 9 kg (20 lbs) counter weight should be able to trow a 90 gr (3 oz) projectile. A tennis ball is about 2 oz, so you could maybe fill it with some silicone to add weight? Adding wheels will allow more energy to be transferred to the projectile.
Tom Stanton did one for tennis balls, though a bit larger scale. On why wheels are beneficial: th-cam.com/video/KpFTyE-wiNo/w-d-xo.html
I watch Tom, and yes the wheels would make it throw better, however historically Trebuchet were built in place and never had wheels. Onager, and Balista often had wheels but never Trebuchet.
Actually the optimal weight ratio is 1:133, so a 90 gram projectile requires 12 kg of counterweight mass. It’s not 1:100 it’s 1:133
Hi I think the problem is the string, if you put a plastic cup on the end to hold the ball I think you would get much more travel and a bit lower so the dogs should see it and run.
You would think so But the cup holds onto the ball for too long throwing it at the ground right in front of the Trebuchet. The Pocket must be flexible so as to release correctly.
@@DIYwithUncleCy the cup has to be small so that the ball will sit in it but not big enough so that it will capture the ball. momentum would hold the ball until speed took over.
No it’s not the shape of the pouch, it’s just a bit too long, im optimizing my own model right now; the sling should be less or equal to the length of the long arm of the trebuchet, any more and it falls limp at the end.
Nor sure if you know about the use of two cannonball chained together. They were to snap mast and four ships rigging. You may never read this but here it is.
The counterweight should be rigid on the swing arm. At the bottom of the swing the weight will move to slow down the arm.
I’m afraid that’s incorrect, while it does pull
Back eventually, the projectile is already in the air by the time that happens. The purpose of the hinge is to allow the counterweight a more direct path downwards in the direction of acceleration (gravity) during the first section of acceleration. As someone else pointed out he could also flip the counterweight on top of the arm to make it fall further.
Had a golf ball one shot about 150ft with 20 pound counter weight and then this wonderful thing called a wild fire came trough and burned everything and now I drew out plans for another one that should lunch that golf ball 400+ ft lol
Golf ball abuse
odd music choice...what is this gangster medieval trebuchet?
Love the Trebuchet ! but I'm not sure your dogs did? Hahaha! : ) : )
Where did you get your Chisel -what brand & is it part of a set? Nice!
Keep warm my Friend! : )
The Chisels are a set from Menards, those are the ones I use on;y in the shop, they never go out on a job.
@@DIYwithUncleCy Thanks! I'll see if I can order a set online?
I've been meaning to get a good set of chisels for a yr. or more so
when I saw yours I figured I should go ahead and pull the trigger
& buy a good set! : ) : )
It's a good design but if you want it to go far you should use a spring
Nah
i built one about 6-8years ago with $20 bucks worth of trim wood and a saw and using cement as sand paper. goal was to spend zero money.
looks like a young kid made it but works great, think ball and weight might have to be closer in weight so pulls more and doesnt whip so much.
i cut a piece of craft leather to be skinny on ends and thicker in middle and sown some yarn around outside to keep ball centered
i got some sling shot hunting balls, about 1/2 oz and got about 1 1/2 - 2 pounds in my swinging cage
i tried to build it small to fit on a shelf, its about 12 inches and arm is long, about 24 inches from ground.
think smaller are more forgiving but takes model tools or more experience than i had/have to make it look good
About 12 years ago I built one with an 8 ft arm and a 160lb concrete weight. It would throw water balloons about 400 feet. An apple would go closer to 500 ft. It was fun. This one was just for playing with the dogs.
I think the cords are too long in your sling. The center of the tennis ball in the sling should be exactly the same length of the arm from long entry to fulcrum
Why did you make the diagonal braces unequal? Why not just make an isosceles right angle triangle with both diagonal supports converging at the top?
Also the sling should be the same length as the throwing arm, that’s to say when it loaded but the trigger hasn’t been set so the counterweight is in the lowest position, the center of the projectile should be at the same altitude as the pivot
Yeah the issues that you’re having at around 20 mins is that the sling is too long, the sling is not in tension all the way up until the ball is released, it just kinda flops by the end, if you made your sling 10cm (or a little less than a standard BigMac in freedom units ;) ) you’d be throwing the ball 1.3-1.5 times farther easy
Looking at it in slow motion, yeah that has to be the issue, the sling should fall limp as soon as the projectile leaves the pouch. If you try it yourself, and tie something with a little bit of mass to the end of a string, you’ll need quite a bit more angular velocity to keep the rope in tension if you hold the rope is shorter. In other words hold the end of the rope and spin it around, you’ll notice that you need to spin it faster to maintain tension when holding by the end of the rope than when holding by the midpoint, same principle here, you need more velocity to keep a longer sling in tension, velocity that is really hard to achieve with a throwing arm shorter than the sling, also the longer the rope the more mass is needed to maintain tension on the rope at all since tension requires a mass to be attached to a string greater than the mass of the string itself, I doubt that the pouch is heavier than the string supporting it once the ball leaves it:
What part of Missouri are from?
Kansas City area
Awesome! I used to live up there too. On the opposite side of the state now.
Need for dog
Increase the weight to 35-45 LBS and like totally double the size of it
I built one several years ago with an 8 foot arm and a 160lb counter weight. Threw a lot of apples about 4 to 5 hundred feet. But that was before my TH-cam days unfortunately.
Well it looked impressive. Quality build but not as powerful as I thought it would be.
Shorten the cord, see if that helps.
Longer arm.
Anyone here from masco