How to get the ball over the overpass!?

[Bohalin]

Our team came up with the concept of a catapult device, niffty idea, it was quickly ruled out, but still the concept behind it was interesting....


the way we thought it out was alot of reliance on our teammates for hurding us the balls then we collect it up and launch it over...

it would have been quiet amusing watching balls hurdle threw the air haha...

some cons of it though were deffinitly in the aiming aspect and the distance of the ball...

[robogeek753]

What was powering said catapult? When we were talking about it, we couldn't think of a safe enough, powerful enough device to do it? (A team member did the physics and put the ball traveling at upwards of 15 mph from ground level, 10 mph from 4 ft. to make it work)

[bmusser]

I am not sure if teams are forgetting the size of the ball. Any gripper that is designed to grab a 40" ball will have to fold up inside of the 38"x28". I am sure you will see some arms that are capable of lifting the ball over the bar. This will require careful design due to the size and weight of this years ball.

[Bohalin]

oh we didnt get that far enough in the catabolt concept... we diceded to toss that out rather quickly too... before we got that far... our team isnt even going to attempt putting the ball over the overpass.... but thats all Im going to say

[Woody1458]

Originally Posted by Swampdude

Well here's what I wanted to do but couldn't because the gigantic flag holder is in the way, although I'd love to see someone try it. Basically, if you could hold the ball at the end of a pole (about 4' long maybe) behind your bot, as you travel towards the bars (finish line), plant the front end of the pole in the carpet with a grippy foot on it, and you pole vault the ball using the bots inertia.
The bot itself is your best source of stored energy which can be transfered into the ball.

If you got this to work, you would probably win every design award your regional offers. lol

[gondorf]

an idea that was thought up by my team was to use a holder underneath the track ball, make the holder go up or down in angle, then have like a pneumatic bulldozer bar shoot out and almost kick it over or shoot if you prefer.

[hunter7]

Can you use springs on your robot, or is it against rules?

[EricH]

Originally Posted by hunter7

Can you use springs on your robot, or is it against rules?

Unless the operation violates <S01> or is deemed unsafe, you can use them. Just expect a little extra attention from inspectors making sure it's safe.

[lopz056]

our new design is that of a forklift type deal. except in the shape of a ring so that the trackball sits in it comfortably. then above the trackball there will be a third arm which will keep the trackball from falling off of the ring/ and then that third arm will also be able to swing in a 360 degree circle so it can be used to "kick" the trackball off of the ring over the overpass. thats our second idea and most likely not the last

[ubermeister]

One of the big problems with ball shooting is that the ball is very elastic, so a lot the force anything shooting into it quickly will be absorbed and wasted. To efficiently shoot the ball, it needs to be accelerated slowly up to a high speed, which is of course very difficult with the size restrictions.

[Lynx34]

We're thinking about a slingshot type design by collecting the trackball into a disc/ring which would shoot the ball over the overpass using the surgical rubber bands in the KOP. We already tried a prototype and it has enough force to get it over 6.5 ft, from the ground. The trick at this point is getting it to fit in the 28" by 38" restriction, but we have some ideas.

Unless of course the guys who want to just make a small car-type robot win the vote on game strategy. Not over my dead body.

[jleibs]

Originally Posted by Swampdude

Well here's what I wanted to do but couldn't because the gigantic flag holder is in the way, although I'd love to see someone try it. Basically, if you could hold the ball at the end of a pole (about 4' long maybe) behind your bot, as you travel towards the bars (finish line), plant the front end of the pole in the carpet with a grippy foot on it, and you pole vault the ball using the bots inertia.
The bot itself is your best source of stored energy which can be transfered into the ball.

So I was thinking about this this morning. Unfortunately I'm unaffiliated with a Team this year so I have nobody to try and convince to look into this

I don't know if this idea is actually that far fetched. Well, at least not the premise of converting bot kinetic energy into actuation.

Simplifying things down, I was mostly thinking about a mechanism which I'll describe in a few steps as follows:

Step 1), Clear out a lot of space in the center of your robot. This definitely involved a very custom chassis.

Step 2) Imagine a pole going through a ring, so that the ring can slide along the pole. Now, mount this ring so that it can rotate in such a way for the pole to do its business. Do so somewhere near the center of your bot.

Step 3) Attach a large, high-friction foot to the end of this pole.

Step 4) Include some kind of actuated latch to keep the pole locked in a position such that the foot is off the ground.

Step 5) Drive forward quickly, then release the latch.

Step 6) Hope that the pole slides down and plants its "foot" on the floor. As the robot continues to drive forward, the pole rotates about the planted foot, being driven by the forward push of the robot at the location of the rotating ring. The rotation and sliding of the ring allow this to happen "nicely."

Step 7) This should be able to generate 30-40 degrees of rotation, at a reasonably high speed with sufficient torque to drive any mechanism you care to implement. The 100 joule figure I've seen for energy that needs to be imparted to the ball really is not that large compared to the kinetic energy of a decent sized robot moving at high speed.

Step 8) Either the other end of this pole flings the ball. Or, what I think would be extra fun: since the ring needs to be able to rotate to accommodate the rotation of the pole, this ring is presumably attached to a shaft. Any number of gears or other mechanisms could be attached to this shaft and used to drive some other mechanism than depends on a large amount of force being delivered over a short period of time.

I hope that wasn't too confusing. Maybe I'll post some drawings this weekend if I have time.

If someone knows of a team doing something like this I would love to hear any success (or terribly tragic failure) stories

[ar2]

Originally Posted by jleibs

So I was thinking about this this morning. Unfortunately I'm unaffiliated with a Team this year so I have nobody to try and convince to look into this

I don't know if this idea is actually that far fetched. Well, at least not the premise of converting bot kinetic energy into actuation.

Simplifying things down, I was mostly thinking about a mechanism which I'll describe in a few steps as follows:

I think it will benifit us all if you drew out your design.
But i am likeing your thoughts in the design process!

[jleibs]

Originally Posted by ar2

I think it will benifit us all if you drew out your design.
But i am likeing your thoughts in the design process!

Ok... this probably creates more questions than it answers... but I think it's enough to help you figure out what I'm talking about if you think through it.

Missing some obviously necessary mechanisms like latch to keep off floor when not in use, resetting device, etc.

If this whets your appetite for more I can try to spend more than 5 minutes drawing. If only I had a white board at home, and different colored markers

Originally Posted by jleibs

Step 1), Clear out a lot of space in the center of your robot. This definitely involved a very custom chassis.

Step 2) Imagine a pole going through a ring, so that the ring can slide along the pole. Now, mount this ring so that it can rotate in such a way for the pole to do its business. Do so somewhere near the center of your bot.

Step 3) Attach a large, high-friction foot to the end of this pole.

Step 4) Include some kind of actuated latch to keep the pole locked in a position such that the foot is off the ground.

Step 5) Drive forward quickly, then release the latch.

Step 6) Hope that the pole slides down and plants its "foot" on the floor. As the robot continues to drive forward, the pole rotates about the planted foot, being driven by the forward push of the robot at the location of the rotating ring. The rotation and sliding of the ring allow this to happen "nicely."

Step 7) This should be able to generate 30-40 degrees of rotation, at a reasonably high speed with sufficient torque to drive any mechanism you care to implement. The 100 joule figure I've seen for energy that needs to be imparted to the ball really is not that large compared to the kinetic energy of a decent sized robot moving at high speed.

Step 8) Either the other end of this pole flings the ball. Or, what I think would be extra fun: since the ring needs to be able to rotate to accommodate the rotation of the pole, this ring is presumably attached to a shaft. Any number of gears or other mechanisms could be attached to this shaft and used to drive some other mechanism than depends on a large amount of force being delivered over a short period of time.

[joeweber]

We have successfully used a pneumatic to throw the ball over the rack. Pictures of our test robot and some drawings at http://team1322.org/team_news.htm . The idea is to raise the fork lift to just under the rack and with forward motion and pneumatics you can easily throw the ball over with out stopping. The question is will another team be able to drive in front of us to catch the ball so we don’t have to chase it?