Designing a climbing mechanism for 2013... a humbling experience
 

Hi everyone,

Just needed a place to vent a bit really... I've always thought of myself as a creative and resourceful mechanical engineer, but i've got to admit: this year's climbing challenge has got me stumped so far.

I usually have at least an idea for how the challenge can be accomplished, but the 30 point climb has eluded me thus far.

I'd love to hear from other technical people from the first community: has anyone managed to come up with a climbing concept that you would consider simple and/or robust?

I have no interest in knowing what the idea is (I'd like to solve the puzzle on my own, with the team), just to know either way if people feel like they have found a simple solution or not.

I am constantly thinking of the 2010 climbing challenge where I completely missed the "simple" grab&twist solution, and can't shake the feeling that I'm missing a similar one here.

Good luck and may the force be with you.

-Leav

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Yup!

We've got a climbing idea that should be stable all the way up. The devil is in the details, of course, and we're still very much hashing those out, but we're cautiously optimistic that we've anticipated and planned around all of the hazards/challenges (including requisite force, consistent balance, current demands, sudden power loss, etc, etc.)

I'm quite impressed by the game this year, especially the climbing. A level one climb should be achievable by every team (if they plan for it -- a level one climb is much harder if your robot is too tall!) A level two climb is significantly harder than a level one climb, but well within the achievable range for most FRC teams. A level three climb is more difficult still.

But yeah, it's hard. :D

Re: Designing a climbing mechanism for 2013... a humbling experience
 

For challenges like this, you think of 300 overcomplicated solutions before you find the "simplicity on the other side of complexity" (to quote Oliver Wendell Holmes).

We have not discovered a "so simple every rookie should do it" answer to the 30 point hang, but we have found methods that we believe are simple and robust within our team's capabilities.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

You're starting to give me another idea, and I'm pretty sure that I already had a workable one to begin with

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I hit on a simple climber design a couple of days ago. Making a robot that climbs for 30 points looks easy.

Combining that climber design with other mechanisms for handling discs looks somewhat less easy.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

A fall from zone 3 will pretty much end your robots day. I don't really see the risk/reward as worth it. It will be interesting to see somebodies creative solution to this.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

For Sure, I feel your pain. Every feasible idea has had a road block at this point. We have some reasonable ideas involving gripping but are unsure if damaging paint would be a foul. Most of the ideas we have had might be relatively simple for some veteran teams, but multiple moving arms possibly involving encoders and limit switches might not be where we are at this year. Also in a post competitve life, throwing the frisbee will be cool for demo's and such, the climber will never be seen again.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We came up with an inside climb that looks doable and stable, but ultimately decided that it would take up so much space that we wouldn't be able to shoot effectively and climb. I'd be interested in hearing if anyone has a small footprint climber that can get 20 points or more safely.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Our team has thought of several overcomplicated designs and now we have found the simplest design possible we could think of for climbing to the top. We took insiration from some lifter designs from the 2004 and 2010 games. It will be easy for us to make a climbing robot but we will most likely not be adding any shooter or pickup mechanism for frisbies.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I don't think you're alone in your frustration.

I know some teams have the option to simply go for the 10 point hang. If you are confident in your abilities to run and gun, then the 10 point hang can be done in a matter of seconds. Why overcomplicate the process?

My team has 2-3 designs, none of which make me sleep easier at night. So, when we're facing this, the only thing to do is to go down these paths and see what the designs yield.

We're hoping that we'll yield nice, quick solutions, but for now, all we can do is hope.

- Sunny G.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Sorry, but what was the simple grab and twist solution in 2010? My first year was part of the 2011 season so I was just a little curious.

Also, my team has come up with an idea, but early prototyping has shown that balance is pretty important when climbing, otherwise the robot cannot reach to the next level. We'd also like a simpler design than we have now just because we see a lot of things that can already go wrong with our current design.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

For those of you that have ideas for a 30-point climb, would your robot be able to scale to a pyramid of, say, 10 levels without nontrivial changes? Ignore your robot hanging 30 feet in the air.

It seems like some postings I've seen would because it's repetitive, and others have like a full dance routine going on that lands perfectly on top and wouldn't work for any other pyramid.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We think we're onto something, but in order to make an easy to use, simple climber there are a lot of compromises that might have to be made in other parts of the robot. Depends how our prototypes go.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Basically this

We think we have one or two 30 pointers we could handle, but we're still in beta prototyping. And as to danopia's question, yes, it could, notwithstanding the height and a few other logistics (I didn't do any power/battery calculations for 10 levels).

Re: Designing a climbing mechanism for 2013... a humbling experience
 

http://www.chiefdelphi.com/media/photos/35099

Instead of reaching for the high horizantal bar, many teams opted to grab onto the vertical pole of the tower.

We've considered using this meathod this year but including an arm on both ends so the robot could 'somersault' up the pyramid.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Our design is a basic extension of what we did in 2010 - same basic concept, but double the level of complexity to get to the third level. In fact, the level of complexity to go from 2 to 3 is actually less than that required to go from 1 to 2 with this design!

As for adding levels... the changes wouldn't be non-trivial, but they would be direct and obvious. Of course, to go 10 levels we would need a much bigger frame perimeter :p There's an alternate concept that branched off from this one that would allow us to tackle any number of levels successfully - basically the same design with a few added tweaks that amount to a lot of control complexity. But limiting to 3 levels proved much easier in the design.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

"Oh baby, dey goin' fo' da hookup!"

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We have an idea but is it worth the weight and possible fall.
We may just do a 10 easy or 20 hard over a 30 very hard and a lot of weight

Re: Designing a climbing mechanism for 2013... a humbling experience
 

That's true for us, too. Once we're at two, going to three should be essentially a repeat of what we just did... (And to answer the question, we should be able to climb an arbitrary number of levels given time and battery life.)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Partly for that reason, and partly for added stability, our design is basically doubled on each level. Grabbing twice instead of one per level should prevent any catastrophic failures!

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We think we have a solution. Of course, I thought that a few days ago, also.

The challenge is significant, the answers will probably be subtle adjustments to a solid concept. The biggest problems are initial docking (we want it to be simple, quick, robust, and tolerant of poor angles of approach), transitioning from level 1 to level 2 (once you have that, 2-3 is rinse and repeat), and getting all the way up to the top of level 3, so that you are totally above level 2.

Rolling off the post and flipping over backwards are certainly problems. CG will be critical in the climb.

And you must really double check all the geometries out.

Is it risky? Yes.
Is the risk worth the reward? We think so.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Another challenge for some may be the 54" radius. Unless I'm misreading from the Q&A, that is with respect to the floor - so if your robot inverts, it needs to do so inside of a 54" cylinder. They certainly didn't make this a trivial challenge this year.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

This was a question posed to the Q&A a couple of times even and, yes, the 54" cylinder is always with respect to the floor, not the robot. If your climbing scheme includes rotating the robot like the video posted earlier in this thread, you'll need to be mindful no part of your robot breaks the cylinder, including bumpers.

One of the more challenging 'size' restrictions we've had.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Here is our plan that we are trying to flesh out
https://docs.google.com/file/d/0B44TPv-TccPZTTVWLUV0Z0JlM1U/edit
Hope it works

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Our concept it somewhat of a "Monkey Bar climbing" approach.

Here is a quick video I threw together yesterday to demonstrate the basic concept to our team. Please excuse the extra enthusiasm I exhibit towards it's potential success, I'm just excited we have something that might work.

http://youtu.be/9kxMmYTVo0E

Re: Designing a climbing mechanism for 2013... a humbling experience
 

How would you rotate/tilt the bottom half of the bot without applying torque to the horizontal pipe. Tilting or rotating the bottom half of the bot on a unfixed upper point would just change the c.o.g and swing it under the bar further. I think ???

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I think we've found a good solution. I'm especially excited about the possibility of integrating a shooter into the design. Early testing wasn't as awesome as I might have hoped, but I still feel like we have something that will work.

The GDC has done a very good job with this challenge. I've heard some top FIRSTers
saying that only 20 or so teams in the world will be able to hang for 30. At first, I thought that was extreemely pessimistic. Now, I'm not so sure.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

After pounding our head at it a few days, we have 2 designs that we think are within our team's fabrication abilities. I would argue that only one of them is simple but that is an opinion. We're building prototypes of them now and won't know how truly well they work until probably Tuesday next week.

I think "simple" is a relative term for the 30 point climb. A "simple" mechanism for climbing could still have quite a bit of movement.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Wwharrgarbl....

I thought we were working toward a doable design for corner climbing, but I was working from the 2011 robot relative right cylinder. Field relative makes things one heck of a lot more difficult for corner climbing. I'm glad we're designing and prototyping shooting mechanisms in tandem. Back to the drawing board and all that...

Re: Designing a climbing mechanism for 2013... a humbling experience
 

is there a rule for going past the top of the tower with the top end of your robot?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Basically, every single idea iv'e heard or thought of so far has a huge risk, and in most of them that won't be something we are willing to take, strategically speaking.

Than again, I have been known to miss some ingenious stuff in bots that just seemed to work for other teams. (2010 climbers, 2008 shooters/collectors, 2012 stingers...)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

No, but there is the pyramid goal up there that you don't want to run into.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I believe someone on CD posted a Q&A answer stating that Level 3 went effectively to infinity. I would take that to imply that you could go past the top of the tower (to the point where you started being unreasonable, so don't take off for the moon with your robot).

Re: Designing a climbing mechanism for 2013... a humbling experience
 

You still have to be in contact with the tower to get points. So you are actually limited to 84" or so. :]

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We're not back to the drawing board, but that sure did make it more difficult!

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Sir, please state the rule that says you must be in contact with the pyramid (or even transitively supported by it) in order to score CLIMB points.

Seriously, I don't see that anywhere. I've got Q's in to address whether a hoisted robot that's only ever touched Level 0 gets climb points, and whether driving on someone else's 2" tall ramp gets you 10 points.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

At the very least, i'd say the intent is clear.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

A climb is negated if the robot don't touch the pyramid in sequential order.
Hoisting without sequential contact will not net any points... as soon as a robot goes above the first level the referee would push the button and the lights in the driver station would indicate a bad climb.

Good question about whether a robot that is above the floor and supported by another robot would get 10 points.

My guess is that the rule will change to read "fully supported by the pyramid" unless they want to move to more coopertition. In that case you could score two robots by simply having a piece of lexan flop down on either side of your robot that would fit a robot Would not even have to be 2" tall... any height above 0 would work.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I asked a question on the Q&A and you can grab on the center post, the one in the middle of the pyramid goal too if you dont damage it.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

And to add to that, ideas that my team and others have been seen to be out of compliance with the rules. I foresee alot of rule changing within this years manual.

Also, there is a possibility that after the first competitions when bots fall off they may change the rules, or does the people who make the rules intend this to happen or oblivious to it?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We have been wrestling with this since we got the challenge. Because we are concentrating on the climb aspect of the game, we want it to be safe and reliable. Two days ago we came up with a workable design. We prototyped it yesterday, and will be ordering parts from Bimba on Monday.

Let's just say that this idea has some air under it's wings ;)
I'll show myself out.

We'll probably release a video later in the season once we have it working... hopefully.

Good luck. It's a great challenge and I can't wait to see what people come up with.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

You're not alone. Every year I wonder how the GDC will come up with a unique challenge, and every year they seem to figure it out.

We got out our telescopes to try and figure out a solution...

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I track where you are heading with that clue, and we also are testing a seemingly similar "wings" concept, initially with cable tension and surgical tubing wing return.

We may switch to the heavier pneumatics later if we have to, but since we are not going to drive or ever leave the pyramid, our initial plan is to go for minimum possible weight approach first.

-Dick Ledford

Re: Designing a climbing mechanism for 2013... a humbling experience
 

To answer the OP's question, yes we do have a scheme for reaching 30 pts, both by going up the diagonal, and by climbing "hand over hand." However, we are probably not going to do either 30pt scheme, instead aiming for a 20pt scheme.

I'd have to agree that only a few teams will score 30 pts every game.

However, it doesn't have to be because they don't have a good idea, but because they don't even want to chance their robot falling from the 30 pt zone.

Our team is deciding to be safe rather than sorry, and only reach the 20pt zone.

Maybe we'll utilize the full spare parts limit after all...

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I'd be curious to see a pneumatic solution. It seems to me that the air charge necessary -- even with mechanical assist -- is prohibitive. (That said, I'm a particle physicist by training, not a mechanical engineer, and every year I'm amazed at some (much) of the things I see in FIRST.)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

After much hair pulling and uncertainty, I'm confident that we have a working solution that is reliable and will not accidentally drop our robot. We stay within the 54" cylinder with inches to spare and the mechanism looks like it will integrate smoothly with our shooting/pickup mechanisms. Now it is just a matter of detailing the parts.

This is definitely the most challenging thing I've ever had a part in designing in FRC. I'm hoping that the GDC doesn't expand the size limits mid-season like they did in 2011, I think the current rules force teams to come up with extremely innovative designs.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Yeah - we thought we had a good algorithm using pneumatics but after calculating the air required went back to the drawing board. Our mentors are mostly EEs, we feel similarly challenged. Climbing within the rules is a daunting task!

We are now thinking of slaloming up the corner powered by a couple CIMS at 43:3, a modified rack & pinion setup and something looking like skis with a hook on the end.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Good luck. I can't wait to see 30 pt climbers. I think the top row climbers will be like the teams that have stingers. At first almost no one will have them but by champs many will.

Peyton

Re: Designing a climbing mechanism for 2013... a humbling experience
 

The key difference is that a stinger is an 11" air cylinder pointed downwards. A 30 point climber is not quite as trivial to add to a robot with pre-existing space and weight constraints.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

The 30 point climb is a challenge. Almost to where the points should go 5-20-40 for the three different levels. While I'm delighted to see teams "going for it", remember that it is only part of the game... chasing that last ten or twenty points might cost you more elsewhere. Consider...

Is it a better return on investment to figure out how to score all the discs into the 5 point goal and only do a level 1 hang?

It it a better return on investment to practice autonomous and have a pick-up system to allow you to score five extra discs during auto and only do a level 1 hang?

Is it a better return on investment to finish a week early and get copious amounts of driver practice in?

I'd never say don't go for it... but never lose sight of what else you could be doing with the time and resources available to you. From personal experience our "best" years were the ones where we decided to be good at one thing rather than so-so at everything.

Jason

P.S. To those looking at pneumatics... remember that you can use surgical tubing/springs in parallel with your cylinder. Start the match with the cylinder extended, and then retract it... you'll only need about half the air for that first pull... maybe none at all if you do it right.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We have had some major design breakthroughs that are as of yet semi-tested. We have confidence in our ability to not fall off. Also, I'd like to think that it is innovative, and as the lead student CAD designer for the team, I'm psyched for all the work. I cannot wait to see all the teams' ideas.

We haven't been having so many worries on the actual climbing mechanism. However, our pyramid construction was a bit rough, since the specific U-bolts we are supposed to use aren't exactly abundant on the Island, and we started off pretty racked, but we fixed it.

Expect teasers post-build season. After so many ideas going through our heads, I cannot wait to see what everybody does, and how they make it work. Good luck to everybody else, and remember to be super careful while testing your climbing mechanisms.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

There is very little to no risk of falling off with our design.

I just wish we had the parts to actually build it right now.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I worked on the problem all day with mentors and students. My hope was to decide "not gona happen" vs "can be done" so we can decode where to put effort. I think we have a solid 10 AND a viable 20. With effort the 20 may translate into a 30. If so, its a matter of team resource plus risk/reward in the game.

My feeling is that 100% of teams could do 10, but 80-90% will actually make it. 5-10% will attempt or make 20. Less than 1% of teams (who said 20 teams) will make 30. I also believe that a climb ONLY robot can't make it all the way. I will be as excited as everyone else EVERY TIME I see a 30 point climb. This is a really hard one.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Sorry, what's a stinger?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

This refers to a device that many successful teams last year had. It was usually a rod (often pneumatic piston) that dropped down below the drive train after the robot was on the bridge as to help stabilize the bridge and minimize rocking, making it easier to balance. It was easier to add on later in the game because it was a smaller amount of weight (~5lbs or less) and could be added in many places on the robot without too much hassle on the first day of the competition.

-Nick

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I don't see thirty point hangers being added on mid season. To design them, you basically have to integrate it into every aspect of your robot design. It's one of the most challenging design problems in years.

I think it's more likely that you see teams show up to events as pure hangers and then add on frisbee mechanisms over time rather than the other way around. Though I do expect to see a lot of copied 10 point gravity hangers.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

This is how we're looking at it. I don't know if we'll even do floor pickup....we have our plate full just making a short robot that can human load and shoot accurately. The 10 point hang is worth doing, 20 not so much, 30 is just a way to waste our team's time! :p

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Yes, we have a design that is simple, fits a small footprint and potentially will climb to the top in <20 seconds. It should in theory be able to climb to any level without any change.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Funny thing about that theory...

- Sunny G.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

If it can make it to the top when we build it, it can make it to any level. The design does not require changes based on levels, we just have to be careful when building it. A simple error when building could provide quite a headache for us when trying to climb.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

So, would anyone care to explain what kind of gearboxes were used in 2010 for the "Grab and twist" method?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Here's 33's whitepaper on their design. 383 also uploaded videos of their ridiculous unsafe testing procedure to Youtube; they should still be around. Searching for 148's robot Armadillo should also get you some video of their hanger at work; their CAD should also be in CD-Media.

Keep in mind you should only be using these for reference. The 54" rule complicates these designs a lot this year, and the reduction/motor(s) you'll need will be entirely dependent on your climbing design.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Our team realized this right away, we designed a robot that does a 30 point climb and then dumps frisbees into the top goal and every aspect of our robot is dependent on our climbing mechanism. If a team wanted to rig a 30 point climber midseason they would basically need to build a new robot.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Question for you regarding the robot in 3 days. It's climbing is legal or not ? It seemsthat because in touch the floor (level 0) and grog the first horizontal bar (level 1 and 2) it would not be a legal climbing.

Can someone answers ?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

The rule for touching more than two levels only applies to physical contact with the structure (floor/carpet and the steel tubing that comprises the pyramid), not with occupying the airspace. As such, the robot is touching the ground and the first horizontal bar, which is in level 1. No other parts of the pyramid are contacted, making it a legal 10 point climb.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We gave up on the design of a 30-point hanger yesterday. We have had plenty of 'visions' for how to do it, yet they all interfere with our desire for disc scoring. So we're scrapping it and instead will focus on disc launching, chute loading, and floor loading with a 10-point hang at the end.

We also plan to drive under the opponents' pyramids to steal their 2 discs in teleop, if all of their robots are too tall. [maniacal laugh]

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Just don't let them touch you on your way out of the pyramid... ;)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Greetings,

After reading about this "Stinger" idea that extended BELOW the robot frame and wheels years past, I have a question.

Is it legal to have a climbing mast and winch, were the mast would end up extending below the robot as well? Keeping in mind an overall height of 84 inches and the cylinder diameter of 54.

I read the rules and see I nothing against it.

Thanks, and good luck to all.

Troy

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Except possibly the BUMPER ZONE rules... Once the mast goes below the robot, that is now the "bottom" of the robot... R25

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I don't believe the mast underneath would count as "standing normally", but this might warrant a Q&A question.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I feel everyone's pain. Our team uses community voting to choose which design we are going to build, and the community overwhelmingly selected the robot that climbs the pyramid...We have run into one nightmare after another each which required an almost complete redesign. Our current solution will hopefully work, but it counts on a number of subsystems working relatively perfectly so that the whole thing doesn't just bind up.

The new perimeter constraints coupled with the high level of complexity in our design men we are pushing the limits on what our team is capable of on a number of different levels.

Here is to having it all come together.

Edoga

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I believe we have a design that can climb the pyramid reliably 100% of the time (baring mechanical breakdown). It's relatively simple but fabricating it to be reliable is certainly quite hard. Right now turning the mechanical design into something we can fabricate is the big concern. One thing that's proven essential to getting the design working is that we have to build the robot around it. This isn't a component that can simply bolt onto a basic chassis like we typically do.

-Mike

Re: Designing a climbing mechanism for 2013... a humbling experience
 

On Friday, we had a design that could do 3 levels and would need changes to do more. I leave for the weekend, and now the team tells me we have a design that could do 100 levels if we wanted, without any changes :D

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I wonder how many of the 'simple' ideas people profess to have were things we considered and dismissed as being too unreliable, too unpredictable or not simple at all.

We have shied away from anything that relies on the machine's center of mass being in a known, good location or from manipulating that center of mass to encourage the robot to swing into some other orientation. There are too many unknowns there for me to be comfortable putting considerable effort into such a system.

We have some ideas for climbing up the corner that do not require manipulating our CoM, but they have their own challenges. We are likely going to focus instead on frisbee manipulation -- the potential for incremental improvement in that aspect of the game seems more promising to us than the potential, fixed 30/50 pt. contribution.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Anyone who thinks a 30 point hang is simple has no idea what they're talking about, IMO.

There are so many dependencies that affect every aspect of your robot. This is the hardest task we've ever been asked to do and I will bet money there are no more than 30 teams in all of FIRST that do it in an official match.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

And far less will do it in a reasonable amount of time.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I think 'simple' is a relative term. We have an idea that is 'simple' in the sense that it only requires 1 or 2 moving parts to accomplish. I certainly don't think it will be simple to build to work reliably, especially for a team that has a poor track record with past arms. If we go for it I think we will be foregoing shooting and ground pick up to have any chance of success.

A consistent 30+ points sounds very appealing even if that's all we'll do. This is my 10th year in FIRST and I've only been involved with a robot that can score 30+ a match twice. That kind of score makes you an alliance captain at most regionals.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Challenge accepted.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Our team is trying to figure out how to climb the corners, but it definitely does not seem simple. I agree that it is humbling.

We're looking at ways of sitting on the corner joints (the only decent place to sit in a transition between levels) and pulling up on the next corner joint. We have ideas (none simple), and at the stage we're at, I am looking at it more as a system where there are several little climbing subsystems that have to be designed and tweaked properly for the overall scheme to work. I see us slogging through all of the details and prototyping and testing and iterating as opposed to having a flash of insight that makes it twice as easy as we thought it would be.

Our first regional is Kansas City. If we don't do a level 3 climber, I think we'll show up and see that 1625/1730/1986/etc have brought their L3 climbers that also shoot frisbees. If they do, good luck winning with a 10 point hanger. Hard or not, we really want to climb to the top. If we are forced to fall back on a 10 point climber, it won't be for lack of trying.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Excuse a bit of a tangent, but I just wanted to address this line of thought. This isn't meant to be an attack on you so much as it is a counter to a really pervasive idea in FIRST Robotics.

This is really the wrong way to think about this problem. It is oh-so-tempting to get into the "If they do it, we need to as well, or we are automatically worse than them" mentality. I only know this because my teams / I have done it time and time again before.

First - you are never playing a 1v1 match. Yes, it's great if you can go frisbee for frisbee with the big guns, but as long as you have alliance partners you will be able to rely on those partners to achieve the tasks which you can't do.

Second - if you throw 5 weeks into a 30 point hanger because "team X will do a 30 point hang AND shoot frisbees", and you don't use it, that's hundreds of man-hours you could have put into your shooter, your intake, or into drive practice in order to get your scoring rate up at or above their level! The jack of all trades really is the master of none for this game more than many others. And if 1625 matches you frisbee for frisbee and can 30 point hang: assemble a better alliance and the match is still in question. Three specialized robots will often beat one multi-function robot and two supporters.

As anyone who has spent way too much time on the thirty point hang will tell you, getting a solid design that gets you up the tower is a massive undertaking. Every other feature of your robot will be potentially compromised to make this happen.

I honestly think the above debate this year is mostly academic - fears of your local elite team being able to "do everything well" this year are going to be unfounded. The best frisbee shooters (in terms of scoring rate across the entire match) will not be teams that have reliable, working fast 30 point hangers. I predict there will be less than a dozen teams that can 30 point hang efficiently while being even 90% as effective as the top-tier frisbee scorers.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Most important things in life are simple. Few of them are easy!

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Can i get an expert opinion on a design that uses a three stage arm which extends via a pulley system but retracts using a winch powered by a toughbox? The Stages are 27in long with 8in of overlap.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Do you want an opinion on the legality of it? or whether or not such a mechanism could work?

Either way, we'd need a lot more information about the design.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

One thing to remember that 3 robots at the 30 point level (90) will not be done but 1 or 2 times in the 6 weeks of competing. I think the a 10, 20, 30 point combo will be seen more often, I think we will see a lot of 10, 10, 20 so even if you are a 10 point hanger there is a place for you. Remember if you fall 3 to 5 feet trying a 30 point hang your weekend will be over.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I really think Chris hit the nail on the head, as a team that is low on team members and fancy things like water jet cutters, the goal IMO is NOT to be the highest scoring team around, but instead to be the most appealling one to the high-scorers. So instead of trying to do something because the best teams will do it, find something that will make your robot valuable to someone who can climb to level 3 consistently and score a lot of frisbees, and then do that well and spend the rest of your time getting your drivers practice so they can drive the robot well and make it even more appealling.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

So just to keep everyone in the thread updated, Team Update 1-15-2012 has suddenly made climbing a rather lot easier. The 54" cylinder is now robot relative while you're touching the pyramid. Which obviously makes many mechanisms and methods a lot more viable.

My condolences to those of you who have already locked in a more restricted, less robust design based on yesterday's rules.b

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I don't like how the new rules only make certain approaches less restricted. The new size limits are actually more restricting for certain approaches, to the point that some designs are now illegal (like ours for example...)

We can compromise to make it work, but it won't be nearly as pretty to watch. :(

Re: Designing a climbing mechanism for 2013... a humbling experience
 

But perhaps more simple and robust? The new ruling seems to allow for less robot articulation than before. (Just wish they would have changed it sooner)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Nah. I saw the climbing storyboard 842 posted. It was a pretty nice solution to the problem and only needed an arm that was pivoted at the base and presumably a linear lift on either side of that arm. The rest was shifting CGs to position the hooks on the arm. I have a feeling that arm was also 842's pickup and shooter, so I have to say I was looking forward to seeing a team doing pretty much everything on the field with one highly integrated subsystem. I hope they can still work things out.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Yep, pretty much nailed it. :P After an emergency redesign session, it looks like we'll still fit with some modifications. Catastrophe averted.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

This is a good post, and I have pondered it off and on during the past day.

One thing I'd like to add is that we try to evaluate our own abilities as we choose our strategy. We are aiming for something that does more than a minimum competitive concept, but not necessarily everything - we believe we are capable of that. We want to design a robot that can win the regional, rather than getting into elimination rounds as a middle alliance member and then facing long odds against the #1 alliance. If you're trying to win, I think you need to make your best educated guesses about what the competition is going to bring and design accordingly. With that in mind, I think it would be great to quickly finish a bot that shoots, human loads, and does a 10 point hang. But I don't think that is enough to actually win the competition, so I think we need at least one more ability on top of that.

I am still not certain that we are capable of a 30 point hanger, but our progress seems promising enough to continue pursuing it, because the payoff is pretty substantial. We aren't putting all of our eggs in that basket - we are developing a more frisbee oriented robot design as well. Adding a 10 point hanger as a substitute will not be very difficult if we decide to go that route. Splitting our resources isn't ideal, and deciding which route to take will be something we constantly evaluate in this segment of the season.

I'll say this much - this year's game is forcing some really tough choices. I completely agree that it doesn't make sense to try to do everything.

Edit: One other thing I was going to mention - Yeah, I do have a healthy amount of fear that spending too much time on a climber and then having to scrap it will result in a rough season. It's a risk vs reward thing that keeps me awake at night.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

although I'm not working with a team this year (reffing at Peachtree) I have given some thought to a simple climbing device. It would allow for relatively simple removal as well. I'll have to make some sketches of it tomorrow and post it up here :)

I'll give a quick shot at explaining it though.

Picture a wheel, it has no hub, but is still driven. (This can be done) Now imagine it has "fingers" coming off of it, kind of like hooks that would hold the corner of the tower and push it against the wheel. These fingers would alternate which side they held the tower from (left, right, left, etc) and would connect and disconnect by a cam that would push them out (to allow it around the tower corner pole) and then spring force, or surgical tubing, etc. would snap it back, pinching it to the wheel. As the wheel rotates, it simply drives right up the tower, each of its little sloth fingers holding it in place.

Of course this idea isn't remotely fleshed out and would need something like skids to keep the robot from slipping and rotating around (unless that was all part of the plan!), but that is my attempt at relatively simple and reliable

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Whether or not it would work. We actually revised it a little to have 3 stages and a slider peice on the end with hooks attached to it. The robot is designed to be a corner climber. The arm fully retracted fits inside the robot frame but fully extended can reach 38inches. The Arm is fixed on the frame at 60 degrees (The corner posts are 60 degrees relative to the floor not 68 like the sides). We extend the lift arm with a simple pulley mechanism but retract it with a winch that has the cable hooked to the outermost stage and pulls down at 60 dgrees parallel to the The Arm. We also have a wheel mechanism at the bottom of the robot that rides the vertical post as a third point of contact and it is designed to sort of "walk" over the corners of the horizontal bars. Once the arm is retracted fully two sets of hooks mounted to the frame will latch on to the horizontal bar while the arm extends to the next level.

I hope this is the info you would need. :)

Re: Designing a climbing mechanism for 2013... a humbling experience
 

In your opinion the rules forced a less robust design. I disagree. We had a nice robust design that even the most conservative members of our team were happy with. Now it's illegal.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I totally agree, except add to that the fear of watching your robot fall from L3 of the pyramid. That would be a game ender for most robots, and that is what has been keeping ME awake at night. I totally think that it's an achievable task, albeit extremely challenging. However, the GDC wouldn't ask the FIRST community to tackle a problem that they themselves Have not already tackled (to a certain extent), and did not think we could handle.

As to the fear of spending too much time working on a L3 system. Again, I totally agree that it is a HIGH risk and HIGH reward scenario. To devote a serious amount of time and effort working through the problem and fabricating prototypes, just to figure out that for whatever reason ( mechanism doesn't work, weight budget allotment, team change in strategy, system complexity and/or cost) would be a crushing blow to not only the individuals directly involved but to the teams ability to tackle the other facets of the game.

With that said, I know my team has been disproportionately allocating mentor/student resources towards frisbee shooting/collecting and general manipulation as opposed to the climb. It's a safer strategy, and if you run the numbers, an effective shooter can definitely negate a good climber. Now, me personally, believe that climbing is the more interesting challenge and as a result I'm the lone mentor on my team (crazy enough, I guess :ahh: ) to attempt to tackle this problem; and even if I can do it, it will be a tough sell. Again, due to the risk.

I know other teams are dealing with the negative responses to the ideas of climbing, has anyone come up with a valid way to sell a potentially robot destroying strategy, or is the safety inherent in the design? In other words, the safety features of the design / mechanism sells the team on it's feasibility.? Just wondering if anyone else is getting resistance and how you are dealing with it.

Finally, my first climbing prototype, which is no longer the way I want to go about it, had quite the mechanical failure. I thought I would share this to illustrate just what kinds of forces you are dealing with when trying to use an arm to 'curl' the weight of the robot. The shaft was a .5" 4140 steel shaft, acting as the output of a 5-stage AndyMark GEM planetary gearbox giving us a reduction of 666:1. Perhaps I should of known it was destined for failure based off of the reduction. (note: it curled 178 pounds before failing :deadhorse: )

EDIT: And yes, this challenge has completely humbled me!

Re: Designing a climbing mechanism for 2013... a humbling experience
 

Someone just posted this in the thread specific to Team Update 3.
http://www.chiefdelphi.com/forums/sh...&postcount=110

It appears that anything which was legal under the original rule/Q&A responses is still legal.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

What was the output attached to?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

I would like to see team 842s climbing storyboard. Is there a link?

Re: Designing a climbing mechanism for 2013... a humbling experience
 

We have made one thet could work. Not sayinig how, but I'm just gonna say one way valves.

Re: Designing a climbing mechanism for 2013... a humbling experience
 

It's not going to be easy at all. We are still brainstorming ideas to climb, and it's still not looking good, considering we want a robot that does all.