Picking Two other Robots off the ground
 

Do you think it would be a good idea to design your robot to instead of relying on two robots to try and hang from you but to design a way to lift the other two up with you?

Re: Picking Two other Robots off the ground
 

We discussed doing that same thing. However we decided it was not a trivial pursuit considering you have no idea what configuration the other robots on your team will be. The weights are not trivial either. We also weren't willing to give up other characteristics of our robot to do it, so in the end we decided that the risk vs. the reward (a couple extra points) wasn't worth it for us.

Re: Picking Two other Robots off the ground
 

well we have come up with a pretty good idea on how to do so if it pans out do you think it could be an important alliance partner

Re: Picking Two other Robots off the ground
 

In my opinion it should be a simple task to accomplish, just have low hanging rigid bar similar to the field's bar, or as similar as you can make it. I think a lot of people are over complicating the problem, thinking that it will be hard to have something that other robot's will be able to grab, but you know what the need to grab originally so just copy that design as close as you can, you should be able to have robots hang from you if your hanging from the bar.

Re: Picking Two other Robots off the ground
 

I think that teams who can pick up two other robots will be in Atlanta this year.

.02

Re: Picking Two other Robots off the ground
 

That's assuming that the other robots are designed to hang from the bar. That's a pretty big assumption to be making if those 8 points are a major part of your strategy.

Re: Picking Two other Robots off the ground
 

It is an assumption, but it being that big of an assumption is arguable. Yes there are designs being implemented to use the four supporting bars, and other means, to suspend the robot but the large majority will be hanging from the bar as originally intended, and unless your robot design prevents this it should be relatively simple to implement.

Re: Picking Two other Robots off the ground
 

Just make a pair of bars to either side that can slide underneath a robots chassis. Most bots have at least an inch of clearance off the floor if not a bit more. Drop the bars have the other bots drive on top of them and then you can haul all three up, assuming the weight is reasonably distributed.

A crude pic

========= [...........] ==========
[ ... ------------[...........]------------ ...... ]
[......................[...........].........................]
[ ... ------------[...........]------------ ...... ]
.========= [...........] ==========

Bot 1 ........... Your Bot ........... Bot 2


I think that gets my point across? Idk if it is reasonable within the finale config but, hey.

Edit * that pic was a pain, should have done it in paint.

Re: Picking Two other Robots off the ground
 

What about robots who have no plans to hang at all?

Re: Picking Two other Robots off the ground
 

Then it doesn't matter for them at all, there job during competition will be to either run defense by blocking the path of the opposing alliance to their tower or to continue scoring during the finale. What I'm trying to get across is that for robots planning to hang from the bar during the finale they should try and include a way for other robots to hang from them as well, there are simple answers to the solution and if implemented effectively can help you obtain substantial points during the match.

Re: Picking Two other Robots off the ground
 

There are a number of rules that make this difficult to implement. I seriously considered this design and made many non-CAD sketches and plans for it, but abandoned it due to it basically taking away resources from every other aspect of the game.

The main rule is the 84 inch cylinder. This gives you 28 inches or so on each side MAX. to fit, drive on platforms would be shorter in some sections than others. It's a tight fit.

The other thing to consider is the weight of two strong drive on platforms plus a hanging system that can pull 500 pounds in about 10 seconds, while still working if a robot is only on one side of the robot. Weight becomes a big deal, as most designs I had needed dual telescoping arms to get it done.

Plus then you have to be concerned about how many alliance partners can or will be able to climb onto your drive on platforms.

Basically... it's week 4. If you just thought of this today, throw it on the "eh, no one will do it" pile and move on.

Re: Picking Two other Robots off the ground
 

It isn't that simple. How are you going to lift yourself and guarantee your bot can't tip forward or back? Now you need a rigid lift mechanism cantilevered out 3 feet from the tower. That is no easy task. Now you need to make sure you can cross a bump or go under the tunnel. Again, no easy task.

I would suggest that anyone who thinks this might be an easy or simple design challenge pay close attention to the number of teams that actually manage to pull it off and do it well.

Lifting 2 robots in '07 was a far more simple task, and yet you still had a very small percentage of robots that were capable of doing it reliably.

Re: Picking Two other Robots off the ground
 

Lets just say id have to see it work before letting my drivers attempt it. I think you would be hard pressed to find some one to try it first. After they see it work then you might get some people to do it but idk... It would certainly have to look stable.

Re: Picking Two other Robots off the ground
 

Lets say it is a simple concept, and much harder in practice. We did a mock up using a hydraulic car lift in our shop so the COBs do work out , but only with inches to spare. There is a reason my team is not lifting ourselves, much less 2 robots, we don't think it is particular feasible for a team with our kind of experience. This concept is only for if I would attempt lifting, and yes I agree it is waaay to late to start this large of a project. It might however be a good off season challenge.

Re: Picking Two other Robots off the ground
 

Thats why like our design we will be liftingfrom the ground with lowering ramp system and the teams will be lifted with us as one piece

Re: Picking Two other Robots off the ground
 

I hope I get to see this live at least once this season.:D

Re: Picking Two other Robots off the ground
 

YOU JUST MIGHT :cool:

Re: Picking Two other Robots off the ground
 

There is one component on every robot this year that you could know exactly where to grab onto. The bumpers being at a regulated height would allow a robot with a claw to grab onto one or two other robots relatively easily assuming the other robot's frame/bumpers could support the weight and your lifting mechanism was strong enough.

Re: Picking Two other Robots off the ground
 

I for one am a little weary on the idea that drivers are going to easily be able to grab onto my robot in the right place while begin many feet away and not have a clear line of sight. I don't want a driver to miss and then accidentally rip out my electronics or a piece of the robot that wasn't designed to hold 150 lbs.

So yes adding a bar is an easy solution to getting robots suspended, but you have to think about the trust you are putting into another team to not rip your robot to shreds. Not that you shouldn't trust other teams but when it comes to driving robots, as wells as driving a car in real life, i don't trust anyone to not make mistakes 100% of the time (myself included).

Re: Picking Two other Robots off the ground
 

That's the exact opposite of what the original idea of the designs being tossed around in this thread is, though. There are multiple potential methods for lifting an entire alliance regardless of whether or not the other two members were designed to hang. If those 8 points are going to be a large part of your teams' strategy, finding a way to get robot who aren't designed to hang into a suspended position will be a big part of your design challenge.

Beyond that, simply assuming putting a bar in the air will be sufficient for another robot to hang off of you is still awfully presumptuous. You will have to factor in how another robot hanging off of yours impacts your CG (and how that impacts both robots), where that bar will be relative to the field, how to lower each robot at the end of a match, how to avoid complications due to size restraints and the finale configuration (ie, will the haning robot have to be in contact with the tower to get into their finale configuration and can they hang from you if they're contacting the tower?), how to avoid potential damage from hanging mechanisms and suspended robots, and how to elevate (and keep elevated without power) more weight. None of these are trivial questions.

Re: Picking Two other Robots off the ground
 

I think there will be only 1 if any robots at a regional who can lift two robots, and lifting two will be the only thing they do. Lifting nearly 450lbs of robot is a LOT of weight and stress on components. It will take careful planning to coordinate such an operation and is very VERY risky.

My advice- DON'T DO IT!

Good luck! ;)

Re: Picking Two other Robots off the ground
 

we could do it:D :D :D
haha and we were reliable
only team at new jersey regional that successfully scored all 60 points.
yes, we.beast:D GRRRRRR!!!!!

Re: Picking Two other Robots off the ground
 

There is going to be a matter of trust on whether or not you are going to allow another team to use this method, but is something I think we'll be seeing this year. Also as far as the electronics go it is always a common theme for the games that you need to have a robust design, especially when it comes to electrical components, but you should have these components well protected even if you don't plan on doing this.

I still think that a simple bar would be an easy solution and I think you should be able to coordinate this maneuver with little complications. Although I just went back to reread the original post and realized how far off topic I've taken this, so I'll finish here.

Re: Picking Two other Robots off the ground
 

lifting 450 lbs is the easy part by using torqued down motor and pullies but making the frame strong so it won't bend is key but we have figured out a good way to overcome that :) so i can wait to put the bot to its final test

Re: Picking Two other Robots off the ground
 

Those of you who may be considering lifting your two alliance partners in the finale should first answer the question: what would convince you to be a part of a double lift by another team? If you have an answer for that, then I think you just might have a solid starting point for your own design. I'd like to hear the alliance meeting at which two "lifters" are deciding which team will do the lifting. If someone makes a video of it, LMK OK?

Re: Picking Two other Robots off the ground
 

which ever team does a better job of lifting and if your both good pick one meeting spot and who ever is closer then there the lifters

Re: Picking Two other Robots off the ground
 

Tarik,
are you supposing that you will be able (timewise or otherwise) to determine which of your qualification alliance partners is the better lifter BEFORE you have to start a match? A sort of lift-off so-to-speak? Good thing there won't be many teams who think their robot can lift two other bots and then elevate themselves. Or are there?

Re: Picking Two other Robots off the ground
 

no i am saying throught other matches you would be able to tell which is better and whichever team on the field is closer to the pre determined lifting spot is the lifter then if the better lifter isnot in place

Re: Picking Two other Robots off the ground
 

i came up with this and 2 other ideas but, when discussing with other mentors this idea wasn't feasible with the size restraints. also i believe you have to be on the platform anyways so, the question was how to get on the platform, let down the ramps and be able to left both sides with out droping at bot. also they didn't want someone to come and ram into the ramps while lifting. ( it would happen no matter what people say.)

my .02

Re: Picking Two other Robots off the ground
 

Lenny 8,

In first there are no limits so nothing is impossibe. all ideas can work it just depends on how much you believe in that idea and the drive to make it to prove evryone wrong

Re: Picking Two other Robots off the ground
 

In terms of "how to lift two other robots" I've learned early on that you never say this way or that way cannot be done--some team WILL prove you wrong. We think that the easy way to get it done is to is to lift ourselves above the height necessary to allow them to hook onto our bars which serve as both ball control (keeping them from violating the 3" rule) and hanging bars. Once they casually roll forward to hook on we lift only enough necessary to lift them off the ground. This keeps them from worrying about being dropped from a dangerous hieght from an unknown all. Also, the total lift can be done quicker this way.
As for the importance of this feat, I agree with the earlier post, that you will see this often in Atlanta. By then we hope to have it perfected.
BTW. Lil' Lavery,I look forward to seeing the double ramps. I think that is an awesome approach--we were weight challenged after focusing on a variable distance kicker and chose the simpler route.
Finally, lifting 450 lbs. shoulod be easy with what we have available to us this year!

Re: Picking Two other Robots off the ground
 

Some things require more drive than is present in humans. A dual lifter that itself becomes ELEVATED might be that.

Re: Picking Two other Robots off the ground
 

Lifting is an easy job for TENSION elements - think cable/line,
Everything you need for strength to lift 500 lbs of robots (minus energy source) fits in the palm of your hand. Just get some high tech synthetic cable (line as it is called at the marine supply store). A 1/8"x1/4" profile can handle 1000+ pounds, and add an aluminum hook with pulley.. Place your hook on the bar & winch your line. Stop at height where your partners can grab on to you (with their hooks), then keep on winching.
High tech sailing line with 1500 lb break strength costs <$0.50 per foot.
-Dick Ledford

Re: Picking Two other Robots off the ground
 

If you say so ....

... I personally disagree with your assessment of 'easy' and I would be very concerned with robot damage.

Re: Picking Two other Robots off the ground
 

Something else to consider for anyone attempting to do this: hanging mechanisms this year are aiming for a bar 7 feet off the ground. This means that a lot of mechanisms probably won't be able to hook onto anything near to the ground, so the "lift yourself part way, let your partners hook on, then finish lifting" plan may require lifting your robot much farther off the ground than the platform height, leading to longer lift times and more damage when something fails.