67's 2010 Climber

[Derek Bessette]

I haven't used these before, but our team was initially thinking of trying these:

http://www.mcmaster.com/#9833t6/=10ohn3x


They have a remote release that I believe could lock or release the spring on demand.

Pre-loading them safely would be a challenge, but you could possibly go with more springs each with a lower force.

[Alex Guiamet]

Originally Posted by Kevin Leonard

I was trying to find details on HOT's climber back in 2010 and how it was able to scale even after the end of the match. I couldn't find the relevant details on CD or their website. Can anyone direct me in the right direction?

From my understanding there was some sort of gas spring that made the climber normally closed so that once it was hooked on, even if the match ended, it would finish scaling. We discussed how to possibly build a climber to do that but we're stuck on exactly how to go about it.

Kevin, you are correct about how 67's climber worked in 2010. I was a sophomore on the team that year and was one of the students who helped prototype it and build it.

Essentially we utilized four 200 lb gas struts (that were held back by a trunk latch we scavenged form GM's test vehicle scrap) that were connected to a rope and pulley system to pull our bot up.

In the match we just had to extend our arm up (while on the bump) and release our servo that held back our grappling hook to hang. One that servo was released, a 6 lb gas strut rotated a secondary arm that held onto the grappling hook by velcro. Once it had almost extended to its full length, a bike cable released the trunk latch causing the gas struts to extend, pull the rope in, and rip the grappling hook off the velcro so it could align with the center of the bot.

Does this help?

[pfreivald]

Hmm, so that climber would be illegal per Question 504, yes?

That's...harder.

[Jim Meyer]

We used 4 gas struts that were used with a reverse block and tackle system to pull ~36" of rope. It wasn't as easy as it looked. It took us 3 design iterations to get the pull force and the amount of rope pulled right to get a legal hang. It was also huge, being roughly 4" x 6", starting at around 21" and expanding to 36" in length within the frame.

We were just laughing about this the other night as the energy we used to hang actually came from a student. It had a giant crank we used to just pull on the hang rope until the struts were compressed, then just re-latched it.

It is a tremendous amount of stored energy, and must be treated with great care. The benefit of gas struts is they only release that energy relatively slowly though, so it's not too bad. We buried ours inside the frame and latched it with a cross-bar and car trunk latch.

The thing about hanging in 2010, was that it was of such a low point value that it only made sense to do at the last second. Roughly the equivalent of if scaling was only worth 2 points this year. Also, my interpretation of the rules make it so that it wouldn't count. I think the final explanation will be that you have to be up at the end of the match and stay up for 5 seconds for it to count. You really need something like that to be able to judge it, otherwise people would just let their motors back drive at the buzzer.

[Kevin Leonard]

Originally Posted by Jim Meyer

We used 4 gas struts that were used with a reverse block and tackle system to pull ~36" of rope. It wasn't as easy as it looked. It took us 3 design iterations to get the pull force and the amount of rope pulled right to get a legal hang. It was also huge, being roughly 4" x 6", starting at around 21" and expanding to 36" in length within the frame.

We were just laughing about this the other night as the energy we used to hang actually came from a student. It had a giant crank we used to just pull on the hang rope until the struts were compressed, then just re-latched it.

It is a tremendous amount of stored energy, and must be treated with great care. The benefit of gas struts is they only release that energy relatively slowly though, so it's not too bad. We buried ours inside the frame and latched it with a cross-bar and car trunk latch.

The thing about hanging in 2010, was that it was of such a low point value that it only made sense to do at the last second. Roughly the equivalent of if scaling was only worth 2 points this year. Also, my interpretation of the rules make it so that it wouldn't count. I think the final explanation will be that you have to be up at the end of the match and stay up for 5 seconds for it to count. You really need something like that to be able to judge it, otherwise people would just let their motors back drive at the buzzer.

Sounds like a good Q&A question. The 15 points for the hang feels to me to be weighted about the same as the hang was in 2010 in comparison to the rest of the game.

I'm working through a few designs in my head of how to make this work and it just sounds complex to develop, especially in comparison to the design we have currently mocked up.

So the systems involved were essentially: something to extend the climber, something to release the gas springs, and a way to crank it all back in safely.

Am I missing something?

[D.Allred]

Originally Posted by pfreivald

Hmm, so that climber would be illegal per Question 504, yes?

That's...harder.

Thanks for pointing that out. I didn't initially look at the 15" rule that way. But that answer to me says dangling a short robot (like 67's) from a winch cable is not legal.

By the way, 67's hanger in 2010 was awesome to watch!

David

[Jim Meyer]

Originally Posted by Kevin Leonard

The 15 points for the hang feels to me to be weighted about the same as the hang was in 2010 in comparison to the rest of the game.

My memory could be incorrect, but wasn't the hang worth the same as one scored soccer ball?

Originally Posted by Kevin Leonard

So the systems involved were essentially: something to extend the climber, something to release the gas springs, and a way to crank it all back in safely.

Am I missing something?

I think that's the gist of it.

Our climber was the most Rube Goldberg machine we've ever built. The only electronic component of our hanger was a single servo to deploy the hook. Once the hook arm started swinging, the rest was a mechanical process. The swinging hook arm pulled a bike cable that turned the trunk latch that released the gas strut rope winch.

[BrendanB]

Originally Posted by Jim Meyer

My memory could be incorrect, but wasn't the hang worth the same as one scored soccer ball?

In 2010 it was worth two scored balls (2 points per robot hanging).

So its worth three high goals this year.

[Jim Meyer]

Originally Posted by BrendanB

In 2010 it was worth two scored balls (2 points per robot hanging).

So its worth three high goals this year.

Yes, that makes sense. It seemed to take a lot less effort to score a soccer ball that year though, as you didn't have to cross the bump yourself for each ball. We would not take the time to set up the hang if there were available balls to shoot.

[Chris is me]

Originally Posted by BrendanB

In 2010 it was worth two scored balls (2 points per robot hanging).

So its worth three high goals this year.

Well, no, it's really worth two high goals + parking on the platform (which very well might be a place you're shooting those high goals from). Very similar to 2010 in terms of point value when you realize it's just two scored balls more than the alternative.

[Tom Line]

Originally Posted by Jim Meyer

We used 4 gas struts that were used with a reverse block and tackle system to pull ~36" of rope. It wasn't as easy as it looked. It took us 3 design iterations to get the pull force and the amount of rope pulled right to get a legal hang. It was also huge, being roughly 4" x 6", starting at around 21" and expanding to 36" in length within the frame.

We were just laughing about this the other night as the energy we used to hang actually came from a student. It had a giant crank we used to just pull on the hang rope until the struts were compressed, then just re-latched it.

It is a tremendous amount of stored energy, and must be treated with great care. The benefit of gas struts is they only release that energy relatively slowly though, so it's not too bad. We buried ours inside the frame and latched it with a cross-bar and car trunk latch.

The thing about hanging in 2010, was that it was of such a low point value that it only made sense to do at the last second. Roughly the equivalent of if scaling was only worth 2 points this year. Also, my interpretation of the rules make it so that it wouldn't count. I think the final explanation will be that you have to be up at the end of the match and stay up for 5 seconds for it to count. You really need something like that to be able to judge it, otherwise people would just let their motors back drive at the buzzer.

Every time you put your rewind-structure on the top of the bot and your students started cranking, we joked about what they must have done to make you hate them so much