81988E Extropy | Pits & Parts | V5RC Push Back Robot

Added: 2026-05-04

[00:00:04]Hi everybody, it's Tyler here at Vexros.

[00:00:06]We're checking in with the legendary 81988. It's Extrop coming out of Shanghai, China. This team here, I just watched this match. This might be the most impressive robot I have seen here so far at Vex Rolls. These mid goal huggers are just so cool to watch from a match strategy standpoint and how everything comes together for it. But we'll be taking a full dive of this robot here, talking about all the great features for it. A lot of awesome programming choices that you can learn from as well too as a team as you look at future years uh with your robot as well too. But game strategy, you really got to dive more in this team and see what makes them special. Plus 119 dual skills record so far as we're filming this incredible feat that we'll learn more about here on Pits and Parts.

[00:00:47]Thomas, we got to start talking about this mid goal hugger. I just watched it in your match here. I mean, it is so cool to watch and the strategy behind it. Can you talk to me more about how your team came up with it and how you're implementing it on the field?

[00:00:58]>> So, uh, this entire season, um, all the robots has been pretty much similar and there's no evolution since like Mall America. Um, so we thought about like a special mechanism maybe for worlds that we can improve our chances of winning.

[00:01:14]So, this is what we came up with. Um it's basically two uh standoff that we bent using a custom 3D printed mold. Um and our entire robot is designed around this because this has so many parameters that we need to consider. So um first of all um our robot is 28 wide um compared to our old robots which is 27. This is because that the robot needs to go into the uh the logo. So the standoff uh will be long enough to reach uh to block the middle goal while staying the 20 22x 22 in size limit. And because of this we have to um make some sacrifices on I guess on our intake.

[00:02:03]Yeah. So since we're also doing skills, um this kind of set, uh sets some uh parameters for us where um there's a like an ideal height where the second stage roller is for skills, but for matches, the roller need to be the roller and the flex wheel need to be high enough. So when we're in the logo, um the blocks need to not touch any part of the uh flex wheels and the uh rubber band. So we won't uh so we won't sacrifice any points uh on that logo. So uh the our mega hugger it can usually hold four to five blocks uh when when other people are still trying to like dquare hit it or whatever but it will still keep the four blocks in there. And our logo can be like around six to seven blocks. And um and you can al see also see our hook. It's it's uh the starting position is down because that our robot is 28 wide. But we still want a long enough hook for our driver uh to use in match play. So this will stop uh start down and when the march uh when the match starts uh the the hook will go up and but we're and when we expand uh it will still be in the 22x 22 size limit.

[00:03:24]>> From the mid goal huggers themselves, what has the reaction been from either some of your teammates or your opponents? Like when that comes out, do you find that they're find that unexpected that all a sudden you guys are just dominating those mid goals? Um I guess they're it's it's a pretty unique mech and they haven't seen it. So our first match um our opponent just didn't try to like they didn't even try to descore it at all. So that was pretty interesting. But um yeah, so they have been I guess maybe adapting to it a little bit. So they started trying to um descore from it. But uh we've we've seen pretty good result uh results from it that it's not being desc.

[00:04:01]>> Yeah. And I think playoffs will kind of be that really test, right, to see if teams can figure out a way to adapt against this. Uh, I think it's pretty awesome. So, I can't wait to see. Before we get to our next segment, we'd like to thank the following. True competitors know that every second counts. That's why Ketaring University challenges you to dive in right away as a first year student. Participating in robotics programs helps Ketarine students secure a valuable co-op. Whatever your interests, Ketarine gives you more space to work faster and win faster. Learn more at ketarine.edu/vex.

[00:04:31]Let's pass over to Harry talk about some of the programming on this robot here.

[00:04:35]Uh so Harry uh we were talking before that uh your team made a choice to not go with odometry uh and are doing some different sensors with that and then you guys are doing some awesome color sorting too. So talk to me more about it.

[00:04:50]>> We noticed that at previous uh previous seasons. For example, we have over under and also last year with high stake. Both of our generations have been using odometry and then we've been really like we're really mature in whether to manipulate it and to adjustment to it.

[00:05:06]However, we realized that uh because of the element of a parking zone. So, it heavily requires the bar to be fully over and make sure that the bottom is really smooth for us to cross it.

[00:05:19]So, and we realized that comparing to 3.25 25 wheels. 2.75 wheels are actually better at crossing bars because they are higher above the surface. However, we realized the problem because tracking odometry requires tracking wheels and tracking wheels requires them to contact the ground fully and to have a sort amount of elastic elasticity for them to pull up. So in that purpose we have to have a piston to use uh to in order to utilize odometry and because of the nature of 2.75 not touching the ground we'll have to pull the odometry wheels higher above surface and not just to the surface without sinking into the surface. So in that case it might be able to touch the balls within the ball path and causing a blockade and which will interrupt our skills run. And also the odometry wheels themselves are pretty heavy. And when we were designing our bot, we realized that if we add odometry wheels onto the bot, it will exceed the 7 kg limit. And previously in last year, we noticed that seven uh under uh a bot under the weight of seven is most optimal for uh for scales run and also not to overheat.

[00:06:30]Hence, we decided to use distance over dot tree.

[00:06:33]What was the biggest challenge in tuning your robot and iterating that tuning throughout the competition season to get your skill score so high?

[00:06:45]>> So we realized that the most important uh factor that counts into our skills run is the idea of color sorting. Um so at the start we realized that there's uh two main sectors of bots which is linears and also sbots. And for lineers, uh, for color sorting, it's really easy for them because they only simply need to pull down a lever to pull down, for example, elastic band to sort out the ball. However, because we're using Snacky's design, which is the Sbot, we require rollers to uh to specifically store red and blue balls. And for that purpose, we have two optimal uh optical sensors placed on the ball path directed to middle go and the ball path directed to uh to long go. And those two are to make sure that whether when we uh are scoring high goal, the bottom one can read whether the ball under there is blue or red and and then sorting them out through the other way. And we're going to show you how that works with uh the blue and red balls.

[00:07:43]Um so essentially because of our storing mechanism, we're store the ball over here to increase our ball mill. Hence it'll come out this way instead of just going up there. And then for now, I think we're scoring uh blue. So the blue will come out there and the red will stay down there and then be sorted outside.

[00:08:04]Before we get to our next segment, we'd like to thank the following. The Robotics Education and Competition Foundation provides fantastic programs for students from elementary school all the way through college. These include VEX, aerial drone competition, online challenges, JOTC, drill powered scholarships, certifications, and so much more. to discover these exciting opportunities. Visit recf.org and get connected.

[00:08:28]Z, let's talk about match strategy uh and how your team has gone through for it. It's been uh so much fun uh to watch uh your team compete on the field and just you know watching it go through. I think one of the things that was really fascinating to watch is when you are scoring on those long goals, the amount of power that you put into that your blocks where they they just wind up right in the middle. It seems so well tuned to that. Can you just talk me about like how you figure out when are you going to score long goals? When are you going to use that uh trapper uh the block the middle goals? Walk me through how your strategy works for that.

[00:08:59]>> Um so I think the main thing of the strategy is to use the minimum amount of blocks to secure controls because obviously they are the majority of the points uh for a match. So um so basically uh what I did uh at the last match is to just uh find a gap where I got little defense pressure to score on the long goals. Uh so you can see some of my um some some of my like uh push backs with the other robots. I'll just probably avoid it and just find another chance to attack. Um I think uh the one time I remember that I uh only shoot one block onto the long go and it just slide right into the control zone and it just really down to our works of uh of Thomas who is our Thomas who is our builder and um tune the machine. So um yeah that that allows us to just save amount of save a lot of time to uh minimize our wing play. So, when you're scoring on the long goal there, are you varying how much power goes into that or is it a set power that you've done initially?

[00:10:04]>> It's a set power. Um, the only thing I have to control is how many blocks I'm going in. So, maybe if there's a blue control, I'll just score like two blocks in and use wing play to descore the blues. And if it's like empty long, I'll just score one. So, it just mount the time I press the press the uh shooter.

[00:10:24]>> Yeah. looking at uh competition in China and then coming here at VEX Worlds, what has been the big change in your opinion on how the gameplay has been done here at VEX World so far?

[00:10:33]>> I mean uh actually I haven't spent a lot of time in this season. I only joined the team like a few months before VEX Worlds. So I I only played one Chinese match, but one thing I noticed is that um the US teams is much more aggressive on the wing place. uh like they tend to defend more or use their wings more or probably goalkeeping more aggressively uh like you know they can find a balance between uh between giving themsel benefits and not violating the rules. Um so this is one big challenge I've encountered you know um uh in my first few matches uh like I'm not that aggressive on wing play so I actually often lose so I'm actually also trying to find the feeling to uh go against them on long goals. Well, it's been phenomenal to see so far. And speaking about another phenomenal thing, one thing is talk about uh your skills matches uh that you've had 119 in both uh driver control and in autonomous as well too is incredible so far. Walk me through that journey and how you've been so successful in skills.

[00:11:39]>> Okay. So um for our skills for both driver control and autonomous um we decided well the first thing that we were we noticed when we planned our skills route is the hol heavy color dependency of the center goals uh control points. So, we decided to dedicate the six balls in both parking zones as well as an additional seventh ball from one um one of the four um four groups of balls in the middle into our middle and logos. Um other thing that we had to another decision that we had to make was which side of the hongo that our our robot traveled when traveling from one mass order to the other. We decided to go for um we decided to make our robot travel on the outside mainly because of the heavy randomness of what would happen if we crashed into the the balls in the middle specifically the four four balls collected on the corners of the mats.

[00:12:40]>> Well, overall it's been phenomenal to watch your team uh here at Vex Worlds.

[00:12:44]We wish you the best of luck. There is so much I think teams can learn uh from the robot, from your strategy, everything that's gone into it so far.

[00:12:50]So, I can't wait to see how you do here at playoffs as well, too. Thanks a lot.

[00:12:53]We wish you the best of luck here at Vex Worlds.

[00:12:55]>> Thank you so much.

[00:12:57]>> Thanks for watching. Don't forget to like, subscribe, and click the bell to stay uptodate on future fun videos.