Re-Bulding Robots

I have noticed recently that there are a number of teams on the forum who are completely redesigning their robots less than a month before the World Championship. I understand that it may seem tempting to build a completely new design, especially if you have seen it perform very well at tournaments you have attended. However, in my experience, it is the teams who spend the most time practicing driving, programming, and making minor modifications to their robots who have the most success in Vex. It is an important part of the design process to remain fairly consistent in your goals and design and also to learn of minor adjustments that need to be made to such designs through experience rather than through others telling you. I’m not trying to criticize anyone who is doing this - it is a fun challenge to try and build a high performing robot in less than a month - however, most likely the teams that have had time to perfect their robots in every way will have the most success at Worlds. Just a thought I’ve been having recently. It honestly depends on your goals in Vex, but generally, from an engineering perspective, it is good to remain consistent in the design process. I found it odd how many people were attempting this right before Worlds. Especially those that were using the Dual Tread design and are now shifting to the Roller design. Anyway, just my two cents. Just wondering if other people had thoughts on the matter.

tl;dr Why are so many teams changing the design of their entire robot right before Worlds?

I’ve seen teams do this for two reasons.

The most common is what I now call the “Magic Robot Syndrome,” which is the belief that if you just build a Magic Robot that you will win all your matches. After a while, though, you realize that there is no such thing as a magic robot, and winning is a combination of design, build, strategy, practice, programming, and a little luck. If you don’t ever do anything but work on your robot, you’ll never win.

The second reason is the “Experienced Team Making Smart Choices.” Several times in the last six years I’ve seen a really talented team decide that their current robot simply isn’t good enough to win at the next level and build a new one. All of these teams have gone on to compete successfully against other very good teams, and done well at the World Champs.

The trick is knowing whether you are a somewhat-ignorant team trying to find the magic robot or you are the experienced team making a smart choice. Mentors can be of use when trying to figure this out. :slight_smile:

I call it “sick and tired of building NZ-style robots” :smiley:

I think that it can be a good idea to redesign. I always strive to have the best possible robot, and if I see a better robot, I have to make my robot better. However, I agree that teams who start completely redesigning this close to worlds will have a tough time getting everything perfect in time to be able to do well. Redesign early, not late. We did it the day after our first competition in October.

One word: efficiency.

Switching from tank tread designs to the roller design is mainly a process designed to increase capacity or speed. My team doesn’t believe that an NZ robot will always win, but it certainly will better show our capabilities as engineers.

Efficiency also factors into how much time one spends on the rebuild. We’ve been working for a week, and have the entire bot built, minus the plexiglass ramp. We’re moving so fast because we want that extra time to program and practice driving.

Well, it depends on how much time you really have left. 1 month with regular meetings is simply not enough time to rebuild our robot. But we have a 10 day spring break the week before worlds so we decided to rebuild our old NZ robot and make it better. Anyways, NZ robots and dual tread robots don’t take that long to rebuild after you have already built each once and realized what the faults of the first ones were.

If you really know your stuff and have a very clear idea of what you want and how to get it I bleieve that you can build a world class robot in less than a month.

Well our team had to make the decision to either say with our current robot, make minor adjustments, or make a new robot. We decided to have one subteam work on making a new robot, and one subteam work on perfecting the current bot. Me personally since we havent started yet, i think it is going to be quit the challenge to CAD a new robot, and build it in only two weeks…

If you have the parts available, this is the best way of getting a new robot.

There are many reasons for why some teams re-build their robots. There are ALWAYS things to improve on, and if you can find a way to improve your robot, it is generally a good idea to do it.

The only reason for why you shouldn’t re-build is if you can keep your current design and just tweak it, or if you are running out of time. As for the time you need to re-build, we had a member on our team who would completely re-build his robot with only a week or so before a competition.

We’ve just re-built our bot, but that’s mainly just to make a simple(ish) robot that the person going to worlds can drive (we are only sending one member, and the member we are sending has only ever been a co-driver, so driving is a bit hard with a complex robot). Hopefully we will have the time to get ready for worlds. We re-built in 3 days (18 1/2 hours building time, or so another member of our team calculated), and it is already looking good and progress is really quick.


I think you have it a bit backwards.

Teams who settled on a good design early do well because they get to spend a lot of time practicing driving, programming, and making minor modifications to their robots.

Teams who are forced to change their design late for whatever reason don’t have these opportunities and usually aren’t among the best teams. This isn’t the same as doing worse than they would have had they refined the design they had.

To do well, you need to spend a long time improving a good robot. Spending a long time improving a bad robot will not get you anywhere.

I agree with you on this. And I suppose you are right. They might as well redesign if they really think they can improve so much simply by changing design.

In regards to some other posts, redesigning is different from re-building. I should have clarified that when I said changing their robots before Worlds, I meant teams that are changing designs completely without having built them before (Thread title also makes this confusing…). I know that what Jij said about re-building often makes sense as it is good to rebuild robots to make them sleeker and more efficient.

What RickTYler said pretty much sums up what I am talking about.

This is exactly what I mean. People seem to think that they can build a Magic Robot and win with it. Many of the posts I have seen about major redesigns had me concerned that they were in this situation.

And this is basically what it comes down to. The major point here was the last one and I honestly don’t know who are the experienced teams and who are the less-experienced teams. I just think that if you are an inexperienced team, you should be cautious in completely redesigning this close to Worlds.

But regardless, redesigning is a good learning experience and one we have certainly learned from over the years.

Define bad robot, for this game.

I believe most teams that are going for the World Champs should be falling under the 2nd category :slight_smile:

In fact, we have been building new robots almost continuously.
But we will always keep the existing robot that is working, and then work on the new robot.
we will only deconstruct the old robot if the new one is working :slight_smile:

Um, there really aren’t bad robots for this game other than robots that don’t score at all or work. There are inefficient robots that could be made better though. Some examples of robots that do not have peak efficiency are claw bots and I know you are going to criticize me, some dual tread bots.
A good example of testing how efficient your robot and driver are, is by pretending that you have a wallbot on your team, and you are given the three interaction goals, the 2 20" isolation goals (if you can score in the other without getting in the other isolation zone) and your other isolation goals and seeing how much you can score through your autonomous and the 2 minutes of driver control. If you are able to score all your objects within the time limit and still have a few seconds to spare, you have near peak efficiency.

Now back to the original post, like meng said, most teams know what they want and how they will get it. Therefore, they are not risking much by rebuilding their robot if they know for sure that it will be better than just a few days extra of programming and practicing. You can’t really practice for a few hours straight because you might burn out your motors. Also rebuilding gives our bored members some things to do but this isn’t a very important reason.

Sure it is! There are plenty of robotics students with enough acumen to wreak royal havoc in the absence of a productive/benign place to channel their creative energy. :wink:

Another valuable reason for rebuilding a robot is simply to try strategies. Very few of the best teams have been doing Vex for only a year. In the long run, there are numerous benefits to learning by trying different designs, and then using what you have learned, to help you build a good design in the future. Even with different games, there are many concepts and processes that are valuable on any robot, which need to be learned by trying different designs.

I guess what i meant was:

Get a set of teams of varying abilities. Tell them all to build a certain robot design (for example dual tread).

Play them all off against a representative sample of the teams and designs that will be at worlds and see how well they do.

Then tell a similar set of teams to all build another robot design (for example generic side rollers).

Play them off against a representative sample of the teams and designs that will be at worlds and see how well they do.

If the set of teams who built dual tread robots do worse than the ones who built side roller robots, then the dual tread design is worse. That’s what I meant by a ‘bad’ robot - a design that will perform worse than most other designs when built by teams of similar ability.

Of course we don’t know for sure which designs are bad at this point because it depends on what people bring to worlds and how the different designs behave in the metagame. At this point we only have opinions.

My opinion (and I don’t speak for AURA or anyone else) is that dual tread robots and claw robots are worse than side roller robots unless they add something other than scoring ability. Side rollers are just faster at getting objects into goals than either of these designs so this cannot be the thing you plan to be best at if you’re building a dual tread or claw robot.

If you plan to be best at some other element of the game and building a dual tread or claw intake helps you get there then that’s a perfectly valid strategy.

We’re rebuilding our robot because there are some things we feel a robot really has to be able to do to be truly competitive at worlds. Our last robot just couldn’t do those things. Eveb though we do have no experience with this specific robot, we do have a lot of experienxe with the game so far, which could prove to be more important than knowledge of your specific robot (they’re both very important).

totally agree… I even got one of my members to build a mock-up wallbot just for practice. Not that we are going to send a wallbot to worlds… But thought it will be a good idea to have one for practice :slight_smile: