Would it be possible to get a set of plans for this? I am in physics 20 and our final project is to build a catapault and I really like the look of this machine.
@desert951 Sorry, plans aren't available. A frame like this isn't that hard to build. Check out my close-up video of ET for more details and a better throwing arm design. The main axle height is about 4 feet with a 5:1 beam ratio ash throwing arm around 6 feet long. Some of the spring attachment hardware on the arm is custom fabricated. Total cost is around $175-200 USD.
Yeh ino it sounds really odd.but it kind if makes sense because the more weight means that it will pull off the pin easier, that's why my pin is at 40 degrees. Taping a hockey puck to it started as a joke.lol
Great news!! I hit 350ft. To do this I figured out the sling had to be heavier. So I taped a hockey puck to the sling. After hitting a house behind the catapult and almost hitting my dads truck with a ball that shot 300ft straight up I put the pin at 40 degrees and extended the sling length abit and it launched the ball!!!!. Thanks alot for all your help!!!!
It is made out of aluminum and is pretty light. I'm kinda confused about this thing. I belive that the realise angle is wrong. It only went around 50ft high on the 200ft launch
I'm not sure how making a longer sling will work but I may give it a try. I read places that a shorter sling will work but it didn't. So I'm gonna try a longer one
Ok thanks. My arm length it 7.5ft from the pivot point and I have my sling at 5 and a half feet. Does that seem to long, cause with one spring it was a picture perfect launch.
Seems a little short but I have some questions. How strong are the springs in pounds of pressure? How far is it from the pivot point to where the springs attach? What are you throwing and how much does it weigh? Different projectiles have different trajectories given the same sling length. When I throw small pie pumpkins, the larger ones go higher than the smaller ones.
@CBasement Ok first thing is that my sling is 5 and a half feet long from the pocket to the tip of the arm , not the whole sling ( im not sure if u took the 5 and a half feet in the right way since i did not explain it properly, sorry) ok. the springs are 140lbs garage door springs and are attached 1'6 feet from the pivot point. i have to throw a softball for my physics class that probly weighs around half a pound. and like i said before, with 1 spring it launches amazingly, around 160ft
Use a longer sling. Your throwing arm has a lot of speed which is good. Let it out a few inches at a time until you get a good release angle (around 42 degrees).
hi. i built a catapult much like yours and it works great with 1 spring, but once in put the second one on the sling realeases to late so it ends up hitting the ground. So to make it work what do i have to do with the pin at the top? ps. my pin is angled forward abit.
I start with the pin about 30 degrees forward. Then adjust the sling length to get the release you want. Sounds like you need to shorten your sling if your pin angle is correct..
It's a rope that's tied to one side of the frame on an eyescrew that goes over the arm and has a loop at the end that goes between 2 eyescrews side by side. A tethered pin goes through the first eyescrew, the loop and the second eyescrew. Pull the pin hard and away it goes.
This is awesome! Some friends and I have built a few potato cannons but we wanna try to build one of these now and we have a few questions.
What is at the end of the rope on the throwing arm that holds whatever you are launching and how long does the rope need to be? Also, will it work decently with one or 2 springs instead of 4?
Sorry to be so late in replying. The rope is a sling that is attached to the tip of the arm. Do a search on trebuchets or slings for how slings work. Too long to explain here. Length of sling depends on how heavy the projectile is. Sling length determines when the projectile releases. This machine will work with 4 springs using another arm. See my other videos for Emperor Twang. It will hurl a golf ball over 750 feet and a small pumpkin about 150 feet.
The arm has a 5 to 1 leverage advantage on the 600 lbs. of spring pull, so it's like only pulling down 125 lbs. when the springs are at maximum stretch and less initially.
I have to make a catapult for a school project, and i was wondering if i could have some advice. Whats easier to build, a spring catapult or a trebuchet?
Both are about the same. A springapult using garage door springs is somewhat limited in sizes unless you get custom made springs. It needs to be big enough to allow a stretch of up to 40". A trebuchet using counterweight can be any size. Springs can break and when they do they can throw hunks of metal around with great force. If you're using more than 2 average sized springs, you need an extremely strong frame and throwing arm. If something breaks it can seriously hurt you.
um i saw your design and decided to attempt to make a replica of sorts of it. its due in three days haha but i the frame done I'm just not sure as to how to mount the springs and some other stuff. Could you do me a HUGE favor and please send me some pictures of it of different angles if you don't mind. please.
I tried out your 3'x3' requirement in CAD and found a 25-27" garage extension spring will work. Just barely with about a 48-50" throwing arm and 5:1 ratio.
Well because of how limited I am I kinda still am using the idea of having a smaller spring or bungie cord take the place of the massive springs, making sure that they are connected to the end of the arm and making sure the tennis ball can smoothly leave the arm without gettign stuck or slowed down with a "spoon" like holder.
Alright well because of my limitations on my catapult I have to like "shave" it down a bit by making it a bit shorter, but what would you recommend I use to launch a tennis ball on a (maximum) 3ft x 3ft catapult
25"-27" garage springs won't work on a 3'x3' frame. Won't be able to stretch enough to rotate the arm or provide enough power. I'd suggest an onager, or either a Whipper or King Arthur Trebuchet. My 2'x3' onager throw a tennis ball around 210 feet, the Whipper/KA trebs throw it around 150-180. Onager are a bit more work to crank the torsion bundle, the Trebs are easier to use and simpler to build but require more tuning over a normal treb.
Thanks. Feel free to copy. I did. Make sure your frame and axle are strong enough for your springs. A 5:1 throwing arm ratio makes pulling down the arm by the sling rope easy. Simple lever. Trigger is a rope with a loop on the end running over the arm and positioned between 2 eyebolts on the frame. A tug on the pin with a pullstring releases the rope and arm cuts loose. I'm currently working on an 8 spring design for larger projectiles.
Hey I was just wondering, cause I would like to use your idea for a school project im working on, exactly how did you come abotu "readying" the catapult before launch when it would have taken at least 600lbs of force to pull it back if I'm correct? And what did you use as the "trigger" or the rig to actually step back and fire it. Which by the way FANTASTIC video and catapult (5 stars)
ok thanks
desert951 2 months ago
Would it be possible to get a set of plans for this? I am in physics 20 and our final project is to build a catapault and I really like the look of this machine.
desert951 2 months ago
@desert951 Sorry, plans aren't available. A frame like this isn't that hard to build. Check out my close-up video of ET for more details and a better throwing arm design. The main axle height is about 4 feet with a 5:1 beam ratio ash throwing arm around 6 feet long. Some of the spring attachment hardware on the arm is custom fabricated. Total cost is around $175-200 USD.
CBasement 2 months ago
Yeh ino it sounds really odd.but it kind if makes sense because the more weight means that it will pull off the pin easier, that's why my pin is at 40 degrees. Taping a hockey puck to it started as a joke.lol
KonaStinkyRid3R 1 year ago
Great news!! I hit 350ft. To do this I figured out the sling had to be heavier. So I taped a hockey puck to the sling. After hitting a house behind the catapult and almost hitting my dads truck with a ball that shot 300ft straight up I put the pin at 40 degrees and extended the sling length abit and it launched the ball!!!!. Thanks alot for all your help!!!!
KonaStinkyRid3R 1 year ago
Now you're hurlin'. Well done. Sling Heavier? Doesn't make sense to me at the moment. I gotta look into that.
CBasement 1 year ago
It is made out of aluminum and is pretty light. I'm kinda confused about this thing. I belive that the realise angle is wrong. It only went around 50ft high on the 200ft launch
KonaStinkyRid3R 1 year ago
Keep shortening the sling an inch at a time until you get a good 40-45 degree angle release. You're very close to a good launch.
CBasement 1 year ago
I put in 3 springs and I have 1 more. I shortened the sling alot and it threw around 200ft. Which isn't to bad
KonaStinkyRid3R 1 year ago
I think you can get more distance than 200 feet with 3 springs. What is your arm made of? Is it tapered towards the tip to reduce weight on that end?
CBasement 1 year ago
I'm not sure how making a longer sling will work but I may give it a try. I read places that a shorter sling will work but it didn't. So I'm gonna try a longer one
KonaStinkyRid3R 1 year ago
And also, my pin was at 20 degrees forward if that helps.
KonaStinkyRid3R 1 year ago
Ok thanks. My arm length it 7.5ft from the pivot point and I have my sling at 5 and a half feet. Does that seem to long, cause with one spring it was a picture perfect launch.
KonaStinkyRid3R 1 year ago
Seems a little short but I have some questions. How strong are the springs in pounds of pressure? How far is it from the pivot point to where the springs attach? What are you throwing and how much does it weigh? Different projectiles have different trajectories given the same sling length. When I throw small pie pumpkins, the larger ones go higher than the smaller ones.
CBasement 1 year ago
@CBasement Ok first thing is that my sling is 5 and a half feet long from the pocket to the tip of the arm , not the whole sling ( im not sure if u took the 5 and a half feet in the right way since i did not explain it properly, sorry) ok. the springs are 140lbs garage door springs and are attached 1'6 feet from the pivot point. i have to throw a softball for my physics class that probly weighs around half a pound. and like i said before, with 1 spring it launches amazingly, around 160ft
KonaStinkyRid3R 1 year ago
Use a longer sling. Your throwing arm has a lot of speed which is good. Let it out a few inches at a time until you get a good release angle (around 42 degrees).
CBasement 1 year ago
Can you post a video of it? Forget the short sling comment I just posted and removed.
CBasement 1 year ago
hi. i built a catapult much like yours and it works great with 1 spring, but once in put the second one on the sling realeases to late so it ends up hitting the ground. So to make it work what do i have to do with the pin at the top? ps. my pin is angled forward abit.
Thanks
KonaStinkyRid3R 1 year ago
I start with the pin about 30 degrees forward. Then adjust the sling length to get the release you want. Sounds like you need to shorten your sling if your pin angle is correct..
CBasement 1 year ago
all i have to say is holy shit
loku1125 1 year ago
Could you briefly describe how your release works? Not the sling but the actual arm. Thanks.
Byza01 2 years ago
It's a rope that's tied to one side of the frame on an eyescrew that goes over the arm and has a loop at the end that goes between 2 eyescrews side by side. A tethered pin goes through the first eyescrew, the loop and the second eyescrew. Pull the pin hard and away it goes.
CBasement 2 years ago
This is awesome! Some friends and I have built a few potato cannons but we wanna try to build one of these now and we have a few questions.
What is at the end of the rope on the throwing arm that holds whatever you are launching and how long does the rope need to be? Also, will it work decently with one or 2 springs instead of 4?
Thanks
beechbum888 2 years ago
Sorry to be so late in replying. The rope is a sling that is attached to the tip of the arm. Do a search on trebuchets or slings for how slings work. Too long to explain here. Length of sling depends on how heavy the projectile is. Sling length determines when the projectile releases. This machine will work with 4 springs using another arm. See my other videos for Emperor Twang. It will hurl a golf ball over 750 feet and a small pumpkin about 150 feet.
CBasement 2 years ago
how did you pull this down? meaning all the weight?
skillz651 2 years ago
The arm has a 5 to 1 leverage advantage on the 600 lbs. of spring pull, so it's like only pulling down 125 lbs. when the springs are at maximum stretch and less initially.
CBasement 2 years ago
Hey!
I have to make a catapult for a school project, and i was wondering if i could have some advice. Whats easier to build, a spring catapult or a trebuchet?
Oneiva 2 years ago
Both are about the same. A springapult using garage door springs is somewhat limited in sizes unless you get custom made springs. It needs to be big enough to allow a stretch of up to 40". A trebuchet using counterweight can be any size. Springs can break and when they do they can throw hunks of metal around with great force. If you're using more than 2 average sized springs, you need an extremely strong frame and throwing arm. If something breaks it can seriously hurt you.
CBasement 2 years ago
Hello!
um i saw your design and decided to attempt to make a replica of sorts of it. its due in three days haha but i the frame done I'm just not sure as to how to mount the springs and some other stuff. Could you do me a HUGE favor and please send me some pictures of it of different angles if you don't mind. please.
Brutepaintballer 2 years ago
Yeah well I tried your design and it WORKED :D I got first place out of all the classes. SO THANK YOU VERY MUCH :D!
yoshometsuxboxlive 3 years ago
That's great! Congratulations! What did you hurl and how far did you hurl it? Or was it an accuracy contest.
CBasement 3 years ago
I tried out your 3'x3' requirement in CAD and found a 25-27" garage extension spring will work. Just barely with about a 48-50" throwing arm and 5:1 ratio.
CBasement 3 years ago
Well because of how limited I am I kinda still am using the idea of having a smaller spring or bungie cord take the place of the massive springs, making sure that they are connected to the end of the arm and making sure the tennis ball can smoothly leave the arm without gettign stuck or slowed down with a "spoon" like holder.
yoshometsuxboxlive 3 years ago
Alright well because of my limitations on my catapult I have to like "shave" it down a bit by making it a bit shorter, but what would you recommend I use to launch a tennis ball on a (maximum) 3ft x 3ft catapult
yoshometsuxboxlive 3 years ago
25"-27" garage springs won't work on a 3'x3' frame. Won't be able to stretch enough to rotate the arm or provide enough power. I'd suggest an onager, or either a Whipper or King Arthur Trebuchet. My 2'x3' onager throw a tennis ball around 210 feet, the Whipper/KA trebs throw it around 150-180. Onager are a bit more work to crank the torsion bundle, the Trebs are easier to use and simpler to build but require more tuning over a normal treb.
CBasement 3 years ago
Thanks. Feel free to copy. I did. Make sure your frame and axle are strong enough for your springs. A 5:1 throwing arm ratio makes pulling down the arm by the sling rope easy. Simple lever. Trigger is a rope with a loop on the end running over the arm and positioned between 2 eyebolts on the frame. A tug on the pin with a pullstring releases the rope and arm cuts loose. I'm currently working on an 8 spring design for larger projectiles.
CBasement 3 years ago
Hey I was just wondering, cause I would like to use your idea for a school project im working on, exactly how did you come abotu "readying" the catapult before launch when it would have taken at least 600lbs of force to pull it back if I'm correct? And what did you use as the "trigger" or the rig to actually step back and fire it. Which by the way FANTASTIC video and catapult (5 stars)
yoshometsuxboxlive 3 years ago