How to wrap the rope on a Torsion Catapult (Mangonel) 

I've been experimenting with catapults and trebuchets, finally broke down and hit the youtube for advice, and I gotta say THANK YOU! you have a new subscription from me, sir, even if you are a damn yankee!

Both my sons (2 years apart) needed to make a catapult for science class. We followed your guide for winding the rope. Thank-you for it!

@barfGAMER101 depends on the size of the catapult. Just string for a table top size, and clothes line rope for a floor model. Try different types to see which works best. Usually a nylon type rope works well because it has a lot of spring to it.

Kind of hard to say, it depends on the thickness of the rope and on the size of the mangonel. I believe this rope here was about 20 feet in length. Rule of thumb for me is to get as much rope in there as you can fit. That usually works pretty good! thanks for the subscribe and the 5/5. I appreciate it!!!

Thanks for the video. I have 6 kids all close in age and I watch this every time ☺

You are very welcome. Not a fancy video but i think it will be very useful for all the siege engineers out there!

I have a whole bunch of catapults, trebuchets and even a bazooka! Check my video playlists and my website. :)

@UdoraAndrew keep after it, the launch angle is important too, and the type of rope makes a difference. The launch angle can be changed by moving or modifying the crossbar.

Youre welcome! Always open to ideas for vids. Send em along if you have any ideas.

@ZeroTuck Yes, this is exactly right. The number of twists will affect the distance thrown. More twists = more tension which means further throws. Good luck!

Very helpful, this will greatly improve the power of my catapult

@LOP33333 I don't know but it will be a lot. Maybe 30 feet or more. You just get a large piece of rope then keep wrapping it until you can't fit any more of it!

If we twist the sides (for twisting the ropes), the side will twist back because of the tension, right? How can it stay without twisting back?

@ZeroTuck I am not sure how far it fires, I didn't bring it outside. Just bounced projectiles off the basement walls.

@Ksiddful The catapult should launch at 45 degrees. That is much better. The rope gets so tight and the handles get tight. The torsion keeps them from turning on their own.

@devilsMovieBull Depends on the ballista. this possibly could be used for the wrapping of a ballista. 2x because the ballista has two arms.

Thanks for the response. We can make some revisions to the crossbar, maybe fasten it to the front of the vertical 2x4s. I'm also debating with the swing arm. If I used a jigsaw to trim the "shaft" area of the arm and reduce the weight, that should increase the velocity. Our ultimate objective is to be able to launch water ballons from the deck of the cottage down on to the swim raft, so we have a few months to figure out the details.

Hi. I can see now that it works, obviously, because you do it, but the first time I saw this kind of catapult I was skeptical that it would work because I didn't think rope would stretch enough and be springy enough and would just stretch out and gradually rip apart as it's pulled, with little spring to it. That being said, once you make one that works, how long does it last before the ropes get too stretched out and weakened? I always t thought catapults mostly worked with springy arms, like half of a bow.

You are very welcome, have fun with your catapult.

@Spatty95 Yes, this would work. Nylon rope and a whole lot of it. Something like 50 feet , maybe more.

thank you so much your videos and website are so informational and have helped me a lot.

What should the width of my rope be if I'm trying to launch a tennis ball at least 6m? My catapult is the same size as your's

hey will I'm making this catapult and I'm wondering how do you make the end knot

It doesn't matter too much. I just lay the arm flat down because its a bit easier. As soon as you start winding it up is when the tension shows up and the arm gets its spring action.

@rukaxmiku Grats! and you are very welcome! have fun with the catapult.

@jabara83 You really don't need feet to make it effective, just hands so you can twist the rope.

@LOP33333 Probably at least 5-6 feet. YOu will need a big catapult, very strongly built.

You are very welcome. HAve fun and I hope you get an A+ on your Physics project.

@studman4250 That's a very long launch. You willl need a ten foot catapult or trebuchet. Check out my behemoth trebuchet. That one does 50 meters.

@Arperture2008 wow, you get a big catapult and you have to be careful with the wrapping. A lot of tension on those ropes. Could be dangerous. I have no idea about the hurling distance of mine. Just fired it against the walls in the basement. Got a big trebuchet in the backyard though. Trying to finish it up. Buried in snow at the moment.

Depends on which size catapult you made and what size string you use? For the small catapult you will need at least 30 feet and for the large one at least 20 feet, depending on how many wraps you can fit in there.

@hargunjot hmm.. nylon rope works well and you might want to try paracord. I heard that works real well. Are you tightening in the corrrect direction? Sometimes people get that wrong. How far does it fire?

this was a great help for my catapult project:) Thanks

@DEANaLEAN Difficult to say for sure. Generally I have better results with torsion like this rather than bungee cords.

@kandy5kiss69 the rope does matter but there are other things more important. Do you have any pics of the catapult. Be glad to take a look and offer advice.

thanks Sir, just what i needed for my Physics 1 project..

thanks! This video helped me a lot. This is for my science fair project! Thanks

Keep at it. Bigger holes and more rope. Lots of turns on the rope.

Its actually a really good idea. When you put a crossbow on a catapult it becomes a "Ballista" a common siege weapon of the middle ages and the real predecessor to the catapult. I don't make these because they tend to be dangerous. I don't want young ones firing arrows around - until I can figure out how to make an arrow out of marshmallows!!

@the16drummerDT I think I have some stuff about the catapults on my website.

thaks a lot that is the only thing i need to built one

Great description, thanks!!

can u use nylon rope ? any answer would be appreciated. we are building one and are at this spot in the project. thank you

Hey im using this model and i have some questions.... 1 I can only use wood,metal,glue,leather,natural ropes, and strings.. I cant use rubber bands, springs,plastic, tape, nylon or polyester ropes or strings but i can use nails and screws... It needs to be 144 s inches... i really need help its due may 21 2012!!

Thank you so much, you deserved the sub :)

OMG thanks sooooooooooooo much i needed this very badly

what was the width of the rope you used

hey thanks for taking the time to show meh, i get it now ; )

Thanks bro' it helped me a lot for my science project :)

Yes, Sure can. It should work pretty well. Only one way to find out!

i just wanted to know if you have the swinging arm facing to the ceiling while you are wrapping the string around or is the swinging arm flat on the floor?

what was the demonsions of the arm because if you drill a hole in the middle of it for the rope the arm needs to be thick.

What would you use to hold a tennis ball to launch, like a regular sized tennis ball? I plan on entering a contest and you must be able to fire a tennis ball. Any ideas?!?!? Please it's due in a week. Someone reply :(

Thanks. You are very helpful 5/5 and i subscribed

i've tied my rope, and my catapault is 40 cm by 20 cm by 20 cm, its looks similar to your small one, but i cannot find the right rope to use, please help!!

Would it help if you cut a grove on the Handle fora the string/rope?

So do I rotate the rope clockwise or counter clock wise? Or one side clock wise the other counter clockwise?

Thanks! this was a lot of help!

hello, i like your torsion catapult, and i'm going to make one to, but i got a problem... what kind of rope do you use?

thanks a lot! i was wondering how to do this, but now i know :)

You know the rope you used for the smaller torsion catapult, what kind of rope was it? Because the twine I used wasn't able to hold and it snapped when i turned the pegs to increase the tension.

can you tell me how did you decide the length of throwing arm....also i want to tie a sling to the arm... what should be the length of the sling ?

@AnimeLoverx1000 Forgive me. I am new to You tube and cannot figure out how to ask a question of the video poster. Does anyone know if the plans will work if all board measurements are doubled?

Hi, I need your help on a suggestion of what kind of catapult to make that can shoot up to 10 meters and the dimensions can be up to 40cm x 40cm x 40cm Please answer as soon as possible

Yes, definitely.

I have one question Is twine string ok to use

i was wondering if: 1. can you use this same technic for a ballista? 2. how do you make the broom stick handles stay in place? thanks

how long should the rope be for this size of catapult

I can't say for absolute sure but it seems that a nylon type rope seems to work the best.

Hello stormthecastle I really need your help for something, we have a greek themed weekend at my college and each team have to make a catapult that can fire an orange 25 meters at a target. Do you think i can use this catapult and just scale it up or do you have any other suggestions? and also if i scale it up how long af a rope would i need? (Sorry for bad english im from Denmark)

Hi Will, I really need your help! I have to a catapult that can throw a tennis ball, I've got to get this done before the 28th. Do you think I should build this catapult or do you have any other suggestions?Also if I scaled it up how long should the rope be?

how many feet do u need to make it really effective?

You got it!

Would this exact catapult be able to launch a ping pong ball 10 meters in your opinion?

I'd use some other type of natural fiber rope. Maybe cotton or hemp. Bungee cords are a different type of beast alltogether, rubber stuff these days. Any stiff rope that doesn't stretch too much would be much better, otherwise you'll just end up stretching the rope. The action of the launch arm is so short you need a stiff rope anyway.

what type of rope would you recommend for a catapult with an arm about 4.5 feet long and relatively heavy?

@kawaiichaco Cut a plastic cup to size

OMG THANKS THANKS THANKS!! >< IT REALLY WORKED OMG... THANK YOU SO MUCH!!!!!!!!! although... er... the catapult wasn't very strong for tennis balls but it was okay!! tyvvvvm :)

hmm, not sure. A ballista is on my project list though.

would this be good to launch from 8m to 10m long? and what kind of rope do you need? and how long should it be?

Thank you for the video, was a big help :-)

My boys and I built this as a March Break project. We followed directions but the end result was a catapult that failed to launch a tennis ball the length of our driveway (50 ft.) We will try to rewind the rope to see if we can get some more velocity.

yes

the rope cross the center wood behind & front.. or also between the wood.. my cuestion is .. the wood in the center have a hole like the sides wood or not.. i'm not very good for englis :/

hey man can you put bungee rope as well along with the rope to give it even more power?

Its quite difficult to create a model of mangonel with torsion spring

Helped alot

Thanks Will!

What if u wrapped a bunch of twine pieces together. Would that work?

How far away should the handles be from the side boards while putting on the rope?

hmmm. can you send me pics of it? Maybe I can help. Try using a nylon rope, they work better. and the most common mistake is to twist the ropes, when loading the catapult, in opposite directions. Be sure you twisted both forward to load it up.

i love the inthusiism

how much string do i need for my catapult?

is this working for a ballista?

Thanks alot it worked

yes!

that is the only thing i need

@angelavila96 when you twist the the handles, make sure you twist both the handles forward, that way the arm will move up and forward towards the front frame of the catapult. LOL I also did the same when I first made this! :P:P

@COLLATER4L yes

could you tell me the dimensions of the big one?? please