1492 WASABI Post-Worlds Reveal

Hey everyone, now that we’re all back from the World Championship, 1492A and 1492X will be revealing our robots in a bit more detail.

After three days of competition at Worlds here were our results:

-9th out of 84 in the Arts Division (8-2-0 qualification record)
-Picked by 1st seed 2921B from New Zealand then picked 2911A also from New Zealand
-Went on to become Arts Division Champions
-Earned the Create Award for innovative chassis design
-Placed 4th in the World after the Round Robin!

-1st out of 84 in the Engineering Division (10-0-0 undefeated qualification record)
-Picked 2M from Canada and then 188A also from Canada
-Went on to become Engineering Division Champions
-Placed 3rd in the World after the Round Robin!

All in all, WASABI came home with three giant trophies and two banners for our efforts!

As a team, WASABI has emphasized cooperation in terms of the design process. We don’t really think of ourselves as three separate subteams (A, X and Z) but rather as a single team that’s building three robots. We don’t hide any ideas from each other, but rather throw them out for discussion in humongous email chains hundreds of messages long. Not only that, but after every single tournament, all of WASABI sits down in front of a whiteboard and discusses what went well, what went badly and short-term/long-term plans for all three robots. We strongly urge other teams to adopt similar design philosophies, as we believe this approach has been instrumental to our success.

As such, you’ll see a lot of small similarities between 1492A and 1492X in this reveal, but also huge differences.

Now for the good stuff! Since the design decisions for 1492A and 1492X were often made in tandem or in response to each other, some of the subsystem/mechanism explanations will be combined for both A and X.

1492A and 1492X

1492A Drivetrain
-6 motor X-holonomic drive (2 motors per front wheel, 1 per back wheel)
-1:1 torque direct drive
-Unique “fold-out” 4-bar drive train modules
-Pneumatic brake

This drivetrain was developed over the course of the entire season and has won 1492A multiple regional Create awards as well as the Create award from the Arts division at Worlds (credit to 1492A’s captain, Isaku).

At the most basic level, it’s an X-holonomic drive, but with a twist! The two halves of the drive (left and right) are modularized and attached to mini 4-bar linkages. One side of the linkage is attached to the drive module and the other side to the center of the robot that holds up the rest of the robot (arm and intake). This allows the drive to be folded in at the beginning of the game, raising the robot to the 18" height limit, but as soon as the game starts, the two halves drive outwards and the center of the robot falls down to 15" height and approximately 23" width.

Mini 4-Bar CAD:

1492A Flipout Match Video:
http://www.youtube.com/watch?v=GiVXI-G146Y (Start of match at 1:20)

This was designed with many issues in mind. For one, X-holonomic drives take a lot of horizontal space in the robot, since wheels are at 45 degree angles and motors must be attached directly to each of the four wheels. By allowing the drive to fold out wider, enough space is opened up in the front-middle of the drive to house an ample-sized bucket.

1492A’s drivetrain also included a pneumatic brake. The piston pushed a piece of metal wrapped with anti-slip mat into the ground, making it unpushable to maintain both offensive and defensive positioning.

Pneumatic Brake Images:

1492A Lift
-2 motor 6-bar ~13" long
-Unique uneven variable 6-bar
-Can lift up to 25 sacks
-Uniformly tensioned elastics (inspired by 599D Robodox Gateway)

This lift has numerous unique features that increased the efficiency of scoring, descoring, high goal and defending. The most unique aspect of the lift is the uneven variable 6-bar. In Round Up, AURA introduced the VEX community to the 6-bar lift (Fush and Chups). From all years of VEX, there have been tons of examples of uneven 4-bars and 6-bars that allow the lift to lean forward or lean backwards as it raises. However for Sack Attack, roller design robots found that the angle of your manipulator does not have only two positions: scoring and intaking, like say, Gateway. Instead, you have three positions: scoring, intaking and descoring.

Basically, roller design robots wanted the intakes as flat as possible for intaking to allow sacks to slide towards the back of tray more easily. For descoring however, it was beneficial to have your tray lean backwards slightly so that descored sacks fall towards the back of your tray instead of sliding out the front. For the final position, scoring for both trough and high goal, it was beneficial to have the intake lean forwards again to a flat position for faster outtaking (steep ramp).

1492A Uneven 6-bar Demo: https://www.youtube.com/watch?v=3RZwFGpuMSw
1492X Uniform Tensioning Demo: https://www.youtube.com/watch?v=yngtgmTHRRU (Music credit goes to John Ma)

Credits to my teammate John (Jinduckey on the forums) for the mathematical work he put into calculating the lengths of the 6-bar quadrilaterals to get the desired angle change in the amount of space available.

1492X Drivetrain
-6 motor tank drive
-1:1.6 speed direct drive
-Cantilevered unpowered front wheels
-6 omniwheel drive

1492X started the season with a 4 motor 1:1 torque mecanum drive, but quickly found that it had difficulty driving over sacks and that we valued pure speed for quick scoring/descoring trades over the ability to strafe. We ditched the mecanum drive after our December tournament to work on the drivetrain that we have now.

We saw that pushing power and speed would be important for our highly aggressive playstyle so we decided to move two motors from our lift to our drive and to replace the lost arm power with pneumatic assistance (more on that later).

The cantilevered unpowered front wheels are to maintain an 18" wheelbase while also having enough open space in the front-middle of the robot for an ample-sized bucket.

Drive: [http://imgur.com/7pgYdCC](“1492X Development Photos - Album on Imgur”)

We originally had traction wheels as our middle wheels to prevent teams from pushing us sideways, but changed to an all-omni drive to glide along the walls at an angle for the wall sacks and to reduce friction while turning with sacks.

The drive was quite fast and strong enough for mild pushing battles. Although the drive did burn out at times, this was only after severe pushing matches. We were able to win the majority of our pushing matches at Worlds. The speed and the power combined made the important aspect of positioning and transitions between objectives extremely quick and fluid.
This was seen most prominently in 1492X’s QF 1-1: https://www.youtube.com/watch?v=Jg7tdzEny2M

1492X Lift
-2 motor 6-bar ~17.5" long
-3 piston, double stage pneumatic assist
-Unique uneven variable 6-bar
-Can lift up to 20 sacks
-Uniformly tensioned elastics (inspired by 599D Robodox Gateway)

After dedicating two of our four original lift motors to our drivetrain, we needed some extra power on our full-length 6-bar to maintain our lift capacity. We fixed this by adding pneumatic assistance to our arm. Three pistons and four reservoirs provided us with enough air to comfortably lift 15-20 sacks at the beginning of the match and 8-12 sacks by the end.

Pneumatic assist (early iteration): https://www.youtube.com/watch?v=2ewPBltFJSU
Pictures: First iteration Second iteration

Explanations of other specific mechanisms such as the uneven variable 6-bar and the uniformly tensioned elastics are the same as section “1492A Lift”.

Continued below…

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1492A/1492X Intake
-2 motor roller + pneumatic angle-changing polycarbonate tray
-Motors housed inside the roller
-Anti-slip mat covered roller
-Side-sweeper bucket extensions
-Instant release outtake

This intake was inspired by the anti-slip mat rollers that we first saw from a few New Zealand videos. The square roller shape was chosen because it provided a good balance between grip and not throwing sacks out over the top of the roller. The intake square had a diameter of about 5" which was large enough to descore sacks from any position in the trough.

Having the motors inside the roller allowed the motors to be both protected and out of the way so that sacks near the edge of the troughs could be easily descored.

1492X Roller: http://imgur.com/DREiFJ2 http://imgur.com/WumeCg3 http://imgur.com/LIttIoH

The angle-changing polycarbonate bucket has been developed over the course of the majority of the season. There were many intricate difficulties that our two teams slowly overcame as we kept tweaking it. The main problem with flat polycarbonate trays is the dragging issue. You want a flat bucket for efficient intaking, but the weight of sacks can cause the bucket to drag on the foam tiles. We fixed this issue by angling our bucket slightly forward at the bottom position and then exposing ~2" of polycarbonate out the front with no support. These front 2" would bend slightly against the ground, ensuring that the bucket would be able to get under the sacks, but make sure that only ~20% of the bucket was actually touching the ground, mitigating any dragging issues.

The sidesweeper extensions were first tested on 1492X and were found to be quite useful for wall sacks and general intaking, however they had to be thrown out because of size limit issues. 1492A was able to fit them in size limits and made good use of them for the same reasons.

1492X Bucket:
1492A Drive Test: https://www.youtube.com/watch?v=mt4XJGz9IC8
1492X Pickup Test: https://www.youtube.com/watch?v=7kTjEJN4jvw

1492A/1492X High Goal Score
-Connected to tray as a pseudo-4-bar
-Changes angle with the tray
-Back support folds backwards

This piece of 1492A and 1492X was extremely innovative (credit to 1492A’s captain, Isaku). The back of our polycarbonate trays were connected to the high goal mechanisms. This caused the high goal mechanism to flip when we actuated the pneumatics on the tray. This saved us from using an extra piston just for the high goal, or using a passive high goal score which we thought was somewhat inconsistent.

What’s even more innovative was how the mechanism flipped in. Since 1492A and 1492X both had their polycarbonate trays actuated for starting position, the high goal mechanism would stick out of height limits. Thus 1492A and 1492X needed a starting position with the high goal mechanism down and the polycarbonate tray up, but a regular match position where the polycarbonate tray and high goal mechanism would move in tandem.

In the video below, you can see 1492X in starting position for a semifinal match. The roller rests on top of the flat high goal mechanism, however the polycarbonate tray is in its up/scoring position. When autonomous begins, the tray pneumatics actuate, pulling out the connecting joint and locking it. The tray pneumatics then actuate again with the joint locked, pushing the high goal mechanism up which flips the roller out. The tray pneumatics actuate a final time to intake sacks in autonomous.


In the picture below, you can see the joint (the C-channel connecting the two standoffs) in the locked position.

For more development pictures, check out my Imgur. We are, however, still in the process of uploading all of 1492A’s photos (lots of them!):

For more development videos, check out our Youtube pages:

To help support us, check out our Facebook page:

Phew, that’s a year’s worth of work for two robots crammed into a single thread and I hope I did justice to the amount of work our teams have put in. Just as food for thought, 1492A’s engineering notebook topped out at 200+ pages and required three binders to fully document their design process over the course of the season.

We’d love to take any and all questions you may have regarding our robots and our designs and will respond as quickly and completely as we can.

Finally, WASABI would like to thank everyone in VEX that has made these four years for our seniors some of the best years of our lives. From the friends that we have made all around the world to the directors, coordinators and referees that have come to know us so well and from the countless teams that we’ve allianced with to the world-class teams that we’ve competed against - the memories that we’ve created during these four years are timeless and unforgettable. We thank everyone we’ve met and worked with for our success. We’ve truly been blessed with good friends and great competition.

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Kevin, this is amazing. Good work!
Of course, John and Winston, good work as well!
Everybody else too (sorry, I don’t know anybody else :c)

Dayyyyam Kevin! all those awards and banners are well deserved!
im sure you’ll remember and miss these days for the years to come! :slight_smile:
(makes me jealous u get an extra year :wink: )

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So did that packing peanut in 1492A’s roller pass inspection? :wink:

Thanks Eli! It’s been a pleasure discussing things both robotics and non-robotics related with you on the Skype chat!

Haha, I think I already am missing long afternoons working in the garage! I’m going to have to see what I can do to stay involved in the Toss Up season.

Ah, you caught us red-handed! You have no idea how difficult it was to get all of those things out after unpacking the robots! At least we didn’t have any transport problems this year :slight_smile:

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WASABI is one of those amazing teams in VEX that everyone should know about.
Their success is quite remarkable given the impromptu organization !

The 1492A robot was by far my favorite robot at the competition. The pop-out corner holonomic is really nifty.

Thanks for posting a wrap-up thread ! Keep up the great work

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Wasabi’s robots are consistently amazing, and this is no change. It’s cool to see the differences between a “standard” robot and the top-tier teams besides attributing it to magic.

Good job you guys, and good luck wherever you go.

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Thanks for the kind words Andrew! We have great respect for the Discobots VRC and FRC programs as well and could say just as many great things! I will definitely pass on the praise for 1492A’s chassis to their members.

Thanks for the praise and kind words! We’re hoping this more detailed explanation of our robots will be helpful for other teams even if the exact mechanisms may not be applicable to Toss Up.

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Volunteer at the regional competitions! (assuming ur staying in the same general area for school)
Hopefully ill see u next year!

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WASABI is actually sending our seniors all across the country for university. I’ll personally be headed to California and will be looking for opportunities close by to stay involved! :slight_smile:

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And the World Championship is just a few minutes away in Anaheim… :slight_smile:

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Sadly actually just a bit under 6 hours drive haha, but where there’s a will, there’s a way!

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We would all love to see your there at worlds next year.

It is a totally different experience being at worlds but not competing and I for one would love to have you coach me at worlds. Just don’t tell me to descore red.

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Haha, will do Tabor! I haven’t had much experience coaching as I’ve been driving for four years, but it’s definitely an experience I’m keen to try out! I’ve also loved the scouting role, but have had little time to do so between driving and managing the robot/pit!

I do not mean to thread-hijack, but I wanted to let you all know that we welcome college student volunteers at the VEX World Championship. As the 2014 World Championship gets closer we will have a volunteer signup page available, and any WASABI grad (or any other team grad for that matter) will be more than welcome to join us on the staff side of the competition. You will get a whole different view of the event, and get to experience the exclusive Volunteer Lunchroom, too!

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Out of curiosity (while I’m still in high school), could I take a plane out and volunteer if our team doesn’t qualify for Worlds? Or even if our team DOES qualify, could I help out somewhere rather than work with them for the competition? If all twelve or so of us were to go, there would be at least a couple of us that won’t be needed in the Pits and scouting matches.

I’m sorry if this is addressed somewhere in an appendix or something, but I hadn’t seen this question actually asked before.

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You totally can volunteer. In 2011, nearly my entire team volunteered. We ran all of one division, and other members ended up in other divisions as well, such as myself as scorekeeper. Even with only 5 members attending this year, we had one member volunteer for field reset. Its a great experience

Hijack forgiven XD if I can make the 2014 World Championship, it will either be this volunteer option or working with any teams I may still be involved with. It hasn’t even been a month and I’m already itching for another round in Anaheim!

You guys always find innovative solutions for everything! Great robots, I always enjoy seeing the design twists and solutions you guys come up with for everything!

Is there going to be any sort of reveal on 1492Z?

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