catapult

this is a roman onager, or catapult i built for my eighth grade project. i fixed it up for my 9th grade english and science projects, which is when i made this video. its ten' long, 5' wide and 8' tall. it shoots an 8 pound medicine ball around 300 ft. The part we were not able to get working for this video is the sling release, which in a true onager would be attached to the throwing arm with the lines from the bottom of the sling and the lines from the top of the sling would release from a hook on the end of the throwing arm to open the sling and release the projectile. We had trouble with this and so we simplified it by making the sling release with the ball, which probably had an effect on how far it went due to drag. Anyways, it was really fun to make and shoot, and if u have any questions about it... for some reason... ask me.

Update: after making this video we torqued the ropes to much during a demonstration at my school and the side of the frame snapped inwards. It would be extremely hard and money/time consuming to fix the problem, and though it has been about 7 years since this happened I hope some day soon to go back and fix 'er up cause there was too much work and fun put into it to let it rot in a barn.

If you have ever made a catapult of any kind, please let me know! I would love to hear about it, get advice for future projects and hopefully see videos of pumpkins or big rocks flying around :)

Category:

Science & Technology

Tags:

• onager
• catapult
• trebuchet
• roman
• artillery
• ballsitics
• bomb
• badass
• medicineball
• medicine
• ball
• project
• throw
• whidbey
• island
• farm

[ChaosXRewritten]

I too am doing an ongar for my ancient world history project, but a smaller one. About 12in long,6in wide and tall. I was wondering if you could giveme tips on the friing mechanism, the twisted rope.

[willscooper]

yeah for something that size you could just take a caribiner and cut it so its more of a C shape, have a small ring attached to the arm and then a rope to the caribiner to pull back on.

[cameriio]

Nice onager, have been trying to build one but keeps on breaking or is under powered, what kind of rope do you use?

[willscooper]

use someething that can stretch just a little... any rope too brittle will snap or can cause stress fractures on hte main frame

[timrogers500]

now that's sweet...I built an onager a while ago but decided I liked trebuchets better (more range; easier to build?). this makes me want to build another onager :D

[willscooper]

Yea man its sweet... ur right though its WAY hard to make, specially cause there are not any blueprints out there. Had to design it too. Sad thing is it broke, I torqued the spring to much and the left side frame cracked a bit, should be easy to fix . U make any trebuchets? I wanna make one tis summer

[Sm3ulders]

at 0:58 face in the sky

[bikeloon]

The one which uses a bow is a mangonel. This is a true onager

[Knukleheada]

does it use a counterweight or a bow?

anyway, thats pretty much a mix of a onager and a trebuchet

[klinkthud]

Excellent! I am working on a ballista/catapulta too!