pic: "You should never go against a robotics kid"

[JaneYoung]

Originally Posted by Pikat

Our school actually asked us to build a t-shirt cannon for rallies, and they actually reimbursed us on the cost of the parts, so that was pretty cool.

Smart school, very smart. They understand partnership, promotion, supporting students interested how things work and like to build them, and fun. They also understand the value of a product. Smart.

Don, I just read your very bad pun. It rocks!

[daltore]

My family makes puns all of the time, but even by our standards, geez, these are bad! And for reference, the term "almost completely safe" can always be disproven. There's blood on the sidewalk at my middle school from when I did a video project with rubber chickens. If there's enough force to hurl a couple of pounds over a football field's distance, there's enough force to cause damage.

[EricH]

Originally Posted by daltore

My family makes puns all of the time, but even by our standards, geez, these are bad! And for reference, the term "almost completely safe" can always be disproven. There's blood on the sidewalk at my middle school from when I did a video project with rubber chickens. If there's enough force to hurl a couple of pounds over a football field's distance, there's enough force to cause damage.

If these are bad, you haven't been around long enough. (There are some threads that were, for a while, almost solid puns. There are about a half-dozen people that you don't give a punny topic to, because they will go after it to the full extent of the humor.)

[Andrew Schreiber]

Originally Posted by daltore

And for reference, the term "almost completely safe" can always be disproven. There's blood on the sidewalk at my middle school from when I did a video project with rubber chickens. If there's enough force to hurl a couple of pounds over a football field's distance, there's enough force to cause damage.

(emphasis mine)

Making a good point, and something we always need to keep in mind, we can think that because the robot is only shooting tennis balls (you never know) that the shooter can't hurt us. If something is moving you need to be alert, and you need to make sure you take all precautions.

[Eugene Fang]

If it doesn't rain tomorrow, we will be shooting some video of the "catachet" in high quality and at 240 fps.

[Eugene Fang]

Hey, everyone!

We shot some slow motion videos (it moves so fast that it's still not that slow...), and we found that the catapult isn't even close to being optimized. We we hope we can push another 50 meters out of it.

See the video here:

http://www.youtube.com/watch?v=XqCeL_rW88M

(you can click "Watch in HD" on the bottom right for better quality)

[takeegan]

sorry to butt in and sound like a nerd, but it's a torsion catapult. if you look at Da Vinci's designs thats how it's labeled, and he's a bigger nerd than i ever will be.

[PAR_WIG1350]

catapult is a very non-specific term.
there are many different types and forms of catapults:
-Trebuchet:
----Floating arm
----Fixed arm
-Torsion catapult
----Balista, Scorpion, etc. as well as the stereotypical 'catapult'
-Steam catapult
----launch aircraft off short runways
-magnetic catapult
-etc.

all of these fall under the category of "CATAPULT"

[Edoc'sil]

I was watching your slowmo vid and I had a sugestion or two. I built a true trebuchet with a free swinging counterweight of over three hundered lbs. I had some issues with rocking, and seeing as the thing is 16 ft tall I did not want it tipping over. After I added wheels and not only did it stop the treb from rocking it also increased the throwing distance by about 40 ft. Idk if it will increase your throwing distance, but it will stop some of the shaking that you could see in the last frames of the video. By the way I used wheels that were intended to be used on the Regolith, but were damaged while using them on our shop's floor. They come with nice bearings, maybe you have some extras tying around too.

[Eugene Fang]

Originally Posted by Edoc'sil

I was watching your slowmo vid and I had a sugestion or two. I built a true trebuchet with a free swinging counterweight of over three hundered lbs. I had some issues with rocking, and seeing as the thing is 16 ft tall I did not want it tipping over. After I added wheels and not only did it stop the treb from rocking it also increased the throwing distance by about 40 ft. Idk if it will increase your throwing distance, but it will stop some of the shaking that you could see in the last frames of the video. By the way I used wheels that were intended to be used on the Regolith, but were damaged while using them on our shop's floor. They come with nice bearings, maybe you have some extras tying around too.

You mean like this?
http://www.chiefdelphi.com/media/photos/32412

[Edoc'sil]

Yup exactly like that. Did it change your throwing distance at all?

[Eugene Fang]

Originally Posted by Edoc'sil

Yup exactly like that. Did it change your throwing distance at all?

Those wheels aren't actually attached. It was a robot teaser.