View Full Version : Why you designed your robot
04-13-2002, 03:49 PM
I just wanted to know why teams choose the design they went with for their robot. And what they thought they could have done better.
04-13-2002, 06:38 PM
I think if we had to do it again and we know what we do now, we would put all of the motors in the drivetrain geared for medium speed about 6 feet/sec with a double goal grabber and a killer tread system that lifts the goals also.
04-13-2002, 07:00 PM
it was an issue of time, weight, and what a majority of the team thought was important
04-13-2002, 07:30 PM
I think a majority of the teams would say if they would go back they would build some awesome 2 goal grabber with treads and such, or as I like to call them, boxes on wheels. I want to send out a big congratulations to teams that went beyond they boxes on wheels mentality, sure it wins finals for you, but what's the fun in that? I guess it all depends how you want to play the game, if you just want to play half the game, or if you want to play all of it. I'm sure this issue will come up many times for many future games, sacrificing design for a killer drive system, but like I said its all about how you want to play the game, and I know I want to play all of it.
Proud to be a 31er
modularity is king
04-13-2002, 08:49 PM
I am sure that we will not have the same game next time, so if u r thinking on what to do on the robot next year, then make sure that u take in to consideration that your robo will be doing a different task.
Hmm, if we were going to do it again, well we already have the drive, we would just make something to grab goals. We kinda spent too much time worrying about getting the power and ran out of weight/time to make something to grab a goal - or in asher's words, we sacrificed design for a killer drive system.
Ahser, you said, "I know I want to play all of it." Does that mean you wanna make an uber-cool robot, or make the relatively simple power guy?
04-13-2002, 09:18 PM
perhaps i should explain myself a bit more,
Team 31 always tries to design to be modular, it is our goal to cover as many aspects of the game as possible. In the case of this year we had several "modes" but our 3 primary modes were that of a ball basket/1hook or balls of floor/basket/1hook or 2 hook. We always strive to design our machine to be the best we can possibly think of, and sure its really hard to get all that in and make weight and size, the answer (at least for us) -- modularity. I'm kinda sad we didn't get to use more of our modes for St. Louis (we only got to use one :() but hey there's always next year (and yes I know it will be a different game, I've done 3 different games so far). Sure this system wont work for everyone, but we've found it to be perfect for us. If anyone wants any details on how we design for this or how it all works feel free to IM or email me.
I hope this answers your questions.
still proud to be a 31er
Still not quite sure I understand what you mean by modes. Do you mean different tactics, or something like your bot is actually a $5000 lego set where you can take off parts and add other parts for different gameplay?
04-13-2002, 10:37 PM
I'm pretty sure that's what she means.....
Last year my team was similar....we had our robot with 2 goal grabbers....then we could add a "deck" to carry a robot around on...or a ball grabber arm to reset the bridge or pick up big balls....
04-13-2002, 10:40 PM
Yeah its the erector set idea, and since we've started using extrusion its really simple. Too bad we didn't take any pictures this year and I only have one from last year, maybe I should try to get some...
Last year was awesome though, we could stand up on the stretcher and turn in circles so we could get big balls up and be pulled around, that was by far my favorite mode ever.
proud to be a 31er
04-14-2002, 12:25 AM
We wanted to make a robot that focused on doing one maybe two aspects of the game really well.
One problem, we all agreed to do one thing, but couldn't agree on which one thing.
So we can grab a goal and pickup balls and have a fair amount of traction.
The challange with doing everything? Weight.
We never ran with our runner due to wieght. We took the compressor off due to weight. Shrunk our scoop due to weight.
That and by not focusing on any one thing, everything works ok, but nothing stands out as an amazingly awsome mechanism.
And the real reason we built our robot?
To get to the other side of course!:D
What is it good for?
04-14-2002, 09:17 AM
When we designed our robot we decided that three things were important: goals, speed, and pushing power. So, from that, we built a two goal grabber robot with a two-speed transmission. With our high gear (9 ft/sec), we can get to the goals very fast, and with our low gear (2 ft/sec) and all-steel construction (heavy, but worth the weight!) we can push almost any other robot.
04-14-2002, 11:01 AM
My team made our design decisions based on efficiently and simplicity. We decided that all the winning teams would be strong 2 goal handlers, so thatís what we went after. We decided that to be a strong goal handler we would need to lift the goals. We decided that to be a strong goal handler we would need more then one speed. To simplify we combined the 2 together, dropping down a second set of lower geared wheels to push our robot and goals up (it works very well).
If we did it again we would save weight and add the drill motors to our drive train.
The game this year did not encourage a lot of difficult design challenges, I think balls were not made worth enough. I think human player balls should have counted for 1 pt, there should have been 2 colors of balls on the field, your teams color would be worth 3 pts and the other teams color would be worth 2 pts. All the same zone rules should have applied, so strong goal grabbers would be needed, but making balls worth more would encourage ball bot development.
04-14-2002, 11:08 AM
It is always a big issue with our team how many aspects of the game we shoudl tackle (as I'm sure it is with every team) and every year we try to do Everything. And after it is all over we argue that we should have just done "insert important aspect here" instead. This year we knew we needed Two goal grabbers, at one point someone said "well we can take off one to put the extension on (because of weight)" and we all shot him down. We knew we were going to need power, lots of power. Now between last year and two years ago we became really good at ball handling and building extender arms. Last year we grabbed a big ball with an articulating arm and the extension worked next to perfect, and two years ago we had a basket that went up and down. So it was an obvious decision for us to make a basket to put balls in. I had an awesome idea for being able to hold a goal and collect balls at the same time , and then being able to get another goal, but we all realized how ridicoulously heavy it would be, so we dumped the idea of picking up balls, and we fell back on our strategy of two years ago with getting them into the basket from the player station. Yesterday we altered the program and now we have shaved about 3 seconds off of the ball loading process (made the extender go up faster) and about another 5 seconds off the actual dump process (all automatic). The tether is another issue that we all had great ideas on, including a mouse bot, airplaines, something like a snake in a can, pnuematic ball launcher, or the most recent, putting our bot into "Double Secret Override Mode" (which listens to NO limit switches) and lauching our basket across the field;)
My point being, somtimes you can do some things with a lot less risk, and a lot less mechanism then other things (Getting balls from player station VS. the field) and yes I know that there are 40 balls on the field versus the 10 behind the players station, but other bots can stop you from getting the ones on the field, not so with the Player Station,
Good Luck Everyone!
oh oh oh I almost forgot the point of this thread, if we were to redo it, we would make everything LESS durable, we made our bot WAAAAAYYYY too sturdy and "ROBUST", if we didn't waste so much weight on the drive system and base we could have made a few other features a little bit better.
04-14-2002, 11:24 AM
We get together the day after the game is announced, break into small groups and brainstorm. Everyone is involved, students, parents, teachers, business partners. No idea is thrown out. We spend the next few days looking at the way the game is played and work the ideas from our brainstorming sessions. Then we start some prototyping while eliminating some of the impractical ideas. The students really drive this part of the design based on strategy and game play on a board, all the while looking for what functions will suit the game both in the qualifying and finals. This slows the process of building but gives us a more refined design before we begin. After that, all systems are open for refinement (redesign) if they prove impractical in competition.
Good Luck, See You in FL.
04-14-2002, 11:52 AM
Our team meets at our school for kickoff, then we have a whole-team pre-strategy meeting, and then we split into strategy groups of 3 or 4 people each. These strategy groups discuss what they think the best strategy will be, and then we reconvene so that each group can present their chosen strategy to the whole team. Every person votes and makes comments on the aspects of each strategy, and a design comittee then meets to go over all of the papers and decides our strategy accordingly.
04-14-2002, 02:26 PM
Oy... this topic always hurts everybody on our team to talk about this year. We pride ourselves in being a think tank. We had a kickoff meeting the Tuesday after the game was announced, and conceptualized these awesome robots that could do everything but were so incredibly out of scale we laughed when we measured them. Our project manager, a senior this year, kept egging us on to tweak our designs a little bit, they weren't quite ready yet... until week 3. In the middle of week 3, he left for a ski trip and we never saw him in the build room again.
So yeah. In week 3 our team mom came in and saw us all looking dazed, still trying to conceive different designs with all sorts of permutations with ball grabbers/goal grabbers/ball-goal grabbers, etc. and no robot at all. She then gave us a quick speech on how much this event cost the team and what exactly she would do to us if a chassis was not on wheels moving around by the end of week 4. At that point, we scrapped design, went for the most effective idea we could manage (fast one-goal grabber with an unbreakable hold that is reliable and can move around the field with the greatest of ease), and built the darn thing.
You can see the results of our hurried work.. the frame holding our electronics was assembled in less than 2 hours, so it always looks... kind of off. The previously 80 pound aluminum chassis has holes cut in it the size of a dinner plate or two combined. The only precision work on the robot would be the making of gearboxes for the Chiaphuas, which our engineer voluntarily toiled over for 20 hours straight with a lathe (those gears they send us are incredibly hard to machine, as most of you know). We always joke around by saying "When big name FIRST teams talk precision, they're talking around 1/1000th of an inch. When the Mech Techs talk precision, they're talking 'Oh, an inch or two should do'." Even though I joke, however, we still met the goals we set in week 3 on the field - we have a fast robot that, when attached to the goal, has a virtually unbreakable grip (for FIRST robot standards), and it's extremely reliable.
<edit> If we were to do it again, I can easily tell you we would've been a ball collector grabbing at least one goal, because that was our original intention. </edit>
04-14-2002, 10:32 PM
Our head engineer has always designed our robot for finesse. This year is no different. He walked in on the first day and said "this year we are going to have all wheel turning, swerve drive" and so we do. We have two very strong goal grabbers but we don't use them because they just slow us down. Looking back, I can say that, yes, to win you need a double goal lift and spin robot like 469 and 60, and i could say that i want on of those robots, but i think that what we have this year is so much better than a beast of a robot that can't be moved, we have something new. And i would recommend to anyone who hasn't seen it yet, stop by team 64's pits in orlando or watch a math cause it truly is nice.
04-14-2002, 11:16 PM
I still like the design of a good ball grabber combined with an awesome 1 goal grabber. This idea of a combo, or hybrid, robot will have an impact at the Championships. But... if we were to re-design our robot, I would like to have a larger ratio between high and low gear, along with a lower towing point.
But... there is a design that I've been thinking during the past week that would work pretty well. I'll try to explain it:
It is a low-profile ramp-bot with two semi-detachable grabbers. All it has to do is this:
... let the opposition get two (or three) goals in their goal scoring zone
... get in the middle of the field and attach to two of the goals
... back up to our alliance's goal scoring zone, detaching our goal grabbers, but leaving them on cable tethers (sorta an entanglement hazard, but we'll take our chances here)
... put down some of those file card wire brush thingys onto the floor and make it so that we cannot move.
... invite our partner to get on top of us (adding to our ability to stay in this location)
... begin "winching" in the cables, drawing the two (or 3) goals to us. This would be a very powerful, low speed pull that no team would be able to resist.
Well, maybe it would work. Even hindsight isn't that clear with this game.
ps... I totally agree with "GilaHumanPlayer"s comments. It was pretty amazing to see team 64 attain the #1 seed at LA without collecting a ball nor grabbing a goal. All they did was drive with extreme skill and conjure the best strategy I've seen this year. Watch out for 64... they know how to play this game.
04-14-2002, 11:49 PM
We figured we had 3 choices:
1. Goal handler
2. Ball handler
Now, I have to stress that we really wanted to have fun this year and make an impression. We built a 'bot for 01 that could do just about everything satisfactorily. It preformed well and held it's own, but it didn't have any flare. It was just like every other 'bot out there with a triangle shape and a gangly looking arm for balls. It was a fine 'bot, but it wasn't much fun to watch or drive.
So, we looked at this game, looked at last years, and decided to do it differently. We decided we wanted to make the best ball vacuum in the game - bar none and look good at the same time. I think we did. As far as I know, it's still has the fastest 20 ball pick up time in the game. If it doesnít, then Iíd like to see the 'bot that does!
But, if you put all that weight, design, testing, space etc. into everything needed to pick up 20 balls and put them in a goal in under 15 seconds, you give up capability like strong goal handling or a send home device. We decided that we would just play our strengths and let our allies cover our weaknesses (our lack of strong goal control). For the most part, it worked. Was it perfect? Of course not. We broke down, our allies broke down, the other alliance stole our goals, messed up the ball line or any number of things that could have and sometimes did go wrong for us. We knew from the start that using such a specialized design would limit us to what we could do if something unexpected happend. Of course, the unexpected happens and when it did it sometimes hurt us. Back in early January, the trade offs and risks seemed worthwhile. I think it still was the right choice for our team.
Why did we make the Ďbot the way we did? Because it was
C. Lotís of fun.
D. Whose going to forget the grasshopper gobbling up all the soccer balls?
Edit: forgot to add what I would have changed! Well, I would have liked to see the atwoods still on the drive train, I think the extra pushing power would have helped us out. Also, we had a pair of air horns on the 'bot, fed off the compressor and triggerd on a solenoid. Some big goal bot blocking our way? Just beep the horns at him and he'll move! I just about died when I heard they where scrapped because of weight. If you've seen 95 run a line of balls, imagine that but with the 'bot screaming like a banshee the whole way. Then you'll know why I wanted them so bad.
I think our robot is the best one we have built untill today. We managed to both grab more than 10 balls and one goal. I'm pretty satisfied with it.
But, as the thread asks, if we would design the robot again, I think we should go for a transmission (for the first time) to be fast when collecting balls and strong when pulling goals (right now we are just fast). I would also suggest that we protect more our robot (an opponent broke our light's cover, and another one flipped one of our measure tapes).
the Gila Monsters have a really awesome robot! I was really proud when they won LA's regional. I felt as glad as if I had won. :) It seems they changed their strategy after the Pacific Northwest Regional, when we won partnered with two goal pushers.
Andy's idea is awesome! That robot could use chiapuas to walk around and three drill motors to pull the goals, and it would certainly receive some awards.
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