Spring Catapult

Spring powered catapult using (4) 150 lb. garage door springs. Frame is mostly 2x6 construction. Throwing arm is 2x4s and miscellaneous metal hardware. Golfball projectile went 732 feet on the longest shot. It's name is Emperor Twang. Catapult has since been upgraded.

Category:

Science & Technology

Tags:

• Catapult
• Hurl
• Trebuchet
• Onager

[desert951]

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.

[CBasement]

@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.

[KonaStinkyRid3R]

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!!!!

[CBasement]

Now you're hurlin'. Well done. Sling Heavier? Doesn't make sense to me at the moment. I gotta look into that.

[KonaStinkyRid3R]

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

[CBasement]

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.

[desert951]

ok thanks

[KonaStinkyRid3R]

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

[CBasement]

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?

[KonaStinkyRid3R]

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