Love the build blog! Do you guys plan to have the intake modification for cubes on by Waco? Very excited to play with and against y’all next week.
Day 46
On the programming side of things we switched the arm over to a profiled PID controllers. The has made the arm move significantly smoother. We still have to spend more time increasing the speed and tuning PID values.
The base joint movement is the slow part of the process right now and eventually we can speed it up a lot more but the gear box is slowly self destructing right now. The arm is a really long lever and the choochoo linkage and wheel take all of the upward and downward force straight into the gear box.
The choochoo gearbox is currently supported by 6 stand offs, 3 on each side. The point where the plates and standoffs connect is slowly deforming and bending. As a result the choochoo gear box has developed a bit of a slant.
For a quick temporary fix we’ll be adding double the number of stand offs along the bottom. I expect this will buy us a day or two of testing at most. Tomorrow night CAD will be redesigning the gearbox to better handle the forces from the arm.
The buddy carry had a big setback today, the belt to the cam shaft has the wrong center to center distance. So that big plate will need to be re cut and everything moved over. The blocks that mount the gas shock had the wrong tap call out so those parts also need to get remade. I’m not sure if the buddy carry will end up on the robot in time for Waco.
Cubes?
The CAD team released the next iteration of the intake tonight. It has a top PVC roller that will be able to intake cubes. The double jointed arm is able to bring the top roller low enough that we’ll be able to intake cubes from the ground. This version also adds two time of flight sensors that we can use to detect if we have a game piece.
The new version of the intake needs 2 shafts, 6 3D printed parts, and 2 plates made. We will easily be able to get this on the robot before Saturday. If testing goes well we should be able to pick up cubes in time for Waco.
@Arakeresurya, Glad you like the blog, we think we should be able to get it on in time for Waco.
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Hi friends,
We’ve been watching your build thread pretty carefully here from 6324 - love the choo choo linkage! We developed something very similar in our design meetings and then someone pointed out you were also doing it!
Regarding your bumper attachment - those 3d printed parts. Have you ran these during a season before? How well do they hold up? Can you release an STL?
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I look forward to seeing ya’lls take on a choochoo mechanism!
We haven’t ran any competitions yet with the bumper mounting system. As of right now I wouldn’t yet recommend it, we are still fine tuning settings for prints and reinforcing the weak points. We’d like it to be a bit more robust.
If you want to play around with it or test it yourself feel free.
Here is the latch and pin assembly
Here is the dove tail and corner pieces
Each bumper latch uses 2 springs with part number 9271K584
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Day 47
The gearbox for the arm was reinforced by adding doubling the number of standoffs by the choochoo wheel. This made the gearbox super rigid and it doesn’t flex when the arm extends any more.
That’s the short term fix to buy us more testing and driving time until the real fix is manufactured. The real fix was finished in CAD last night. We are adding a 1″ x 1″ aluminum square tube across the 2″ x 1″ rail and adding a 90 degree bracket to transfer the load into the square tube. We got lucky on the packaging and were able to fit both 1″ x 1″ square tubes with out moving anything.
The arm programming is functionally complete at the moment. We added another state for the high scoring position. While we are approaching but not touching the grid we’ll hold the upper arm at 90 degree angle so we can just move the base to be in the scoring position. This reduces the chance of tipping and makes it less likely to hit the goal with the arm. The below video runs through all of the important positions for the arm.
We will be working to finalize the scoring routine and then trying to increase the speed a bit more on both joints. The buddy carry got the new gear box plates cut and assembly is under way. If all goes well we should be able to test it on Saturday.
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Day 49
Its been a busy past few days. The arm movement speed was increased on both joints, its at a good spot right now. But faster is always better? If we get really good at cycling and lining up in the next few days we might try to increase the speed of the arm again. Right now the arm movement isn’t the slow part of cycling.
Our driver got some great driver practice today. It was probably an hour of driving the robot around. Tomorrow we should be able to get a few more hours of driving in. Below is a video of one of our cycling runs, we are still learning how the robot behaves and the controls so our cycles are a little slow at the moment.
Overall I’m thrilled with how well the intake is working when on a full arm and robot. The arm is also scoring pretty well and we might be able to increase the speed a bit still.
Today we got a chance to run our first full autonomous routine. We’ve ran plenty of paths but haven’t had the chance to combine paths with the arm and intake until now.
So the good news is the arm and intake work in auto, but the balance command seems to have broken when we added more weight to the robot. Tomorrow we’ll work on fixing the balance and adding a few more autonomous modes.
The buddy carry finally got fully assembled and was wired up to the practice robot today. It should be ready for programming first thing tomorrow morning. The assembly of the second robot started today with the intake V2(cubes) and the arm starting assembly. We also had a few students work on arts and crafts for stand props.
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Day 50
The next iteration of intake went on the robot today. There was a clearance issue with the motor and the sweeper plate that had to get fixed by hand but everything else fit together. Below are two gifs, our first time intaking a cube and the first time scoring it into a high node.
We immediately noticed it is now harder to intake cones near a wall because of the added length on the intake. It also makes it slightly hard to fit inside frame perimeter while holding a cone. But we’ve already got the next iteration of the intake designed to fix both of those problems. The top roller will move inwards making the whole intake shorter(and lighter).
The programming team has been busy working on autonomous and ironing out the kinks with it. The auto balance is now working, just fine tuning paths and scoring. They’ve also been cramming to get the buddy carry code working. So far they have the CAM rotating and the servos deploying correctly and they might be ready to test it Tuesday.
The new and improved choochoo gear box was assembled fully today and is ready to be placed into the competition robot. It’ll get changed over once we get auto working and take a break from driver practice.
We’ve been having problems controlling the choochoo mechanism. The linkage that moves the arm up and down can rotate infinitely around a circle. For each arm angle there are two different spots the choochoo linkage could be in. Both images below have the same arm angle of ~82 degrees, but very different choochoo wheel positions.
Adding to the problem, positive rotation of the wheel does not always result in positive rotation of the arm. At two spots in the wheel it switches and positive rotation will become negative rotation. Lets call these inversion points.
These two things become problems when we are controlling the arm with PID control, closed on the angle of the arm. The PID controller expects that positive rotation of the motor will result in positive angle change. This isn’t true once the arm moves past an inversion point. So far we’ve been trying to avoid the points of inversion. But that doesn’t always work. If we run the arm into something, it can get past the inversion point and the arm rapidly flies down smashing into things. Below is an example of us accidentally command the arm past the inversion point.
We think we know how to solve it but its a chunk of work that we need to sit down and get done. All before our first event on Thursday.
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Day 53
The team leaves tomorrow afternoon for Waco. That means tonight was hectic to say the least. The team was busy packing, fine tuning code, fixing the final remaining problems and finishing documents.
We got 18 lbs of ballast added to the back of the robot, it isn’t that pretty but it was quick and it works great. We used to get tippy with the arm fully extended. The robot is nice and stable with the ballast. The robot was 79 lbs before the ballast so we should land just shy under 100lbs with. Also the handles finally got added to the robot.
The next iteration of the intake works a lot better. It is smaller and grabs the cubes with out shooting them out the backside. Tomorrow we have to finish fine tuning auto with the new weight and fix the problem with the Navx 2 micro disconnecting randomly, then off to Waco!
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Waco District Event Recap
Thursday
Waco is only a short trip(less than 2 hours) from out shop in Austin. This allowed us to spend the morning in the shop making last minute adjustments to autonomous and arm control logic.
There were two small problems that happened in the above video, unknown to us they’ll happen again. The robot was loaded on the trailer and the team departed for Waco.
Inspection went very quickly, the robot weighed in at 104.9 lbs. There were three things that made the inspection go so smoothly, brain pan, clean wiring and no pneumatic components. With no pneumatic components you get to skip a large chunk of the inspection checklist. I highly recommend it.
After inspection we had some time to perform some deferred maintenance. There was an issue with the intermediate shaft on our MKi4’s. We had this happen a few times in our shop but caught it before any major damage was done. Our replacement shafts arrived very quickly. @PatrickW from SDS handled this amazingly, clear communication, low cost fix, and super quick shipping. Thank you.
We got to take a short break while we sheltered in place and waited for severe storms to pass. Then we finished up replacing the shafts on the remaining swerve modules. Up next on the list was adding a second battery strap, replacing a few broken bumper mounting parts and adding the freshly painted sponsor panels.
Friday
Friday was a rough day for our team.
We managed to make it to two practice matches and got to play with some friends. The first two real matches went okay, our auto got stuck on the middle pole in the second match but we managed to recover. By the third match problems started to show. Our auto gets stuck on the middle pole again and the upper joint of the arm ends up in a bad state and becomes uncontrollable. We barely manage to climb on the charge station and wait out the remaining match time.
The next match goes even worse for us. Our auto gets stuck on the middle pole again and right at the end of autonomous our robot loses communication to the field and it doesn’t return. This was a weird one for us, on the diagnostics page we had a green light on the driver station for Robot, FMS and Radio. But the overall communications and robot code remained red.
Our robot sat dead on the field for the entire tele operated period. The FTA’s looked at the logs and couldn’t find anything that looked suspicious(I’ll grab the logs on Tuesday and post them). They suggested turning off domain fire wall(public and private were off) which we did. We had run 5 matches before this point and hadn’t had any communication issues before this. Not a great feeling heading back out to the field not knowing if your robot will communicate with the field.
The next match we ran an auto which doesn’t attempt to score, we managed to stay connected longer this time. Around 20 seconds in we had our battery fall out and quickly got disabled. A first for me in my FRC experience. This was a low point for a lot of the team three back to back failures.
Failure is an important part of the engineering process. Its expected, you can’t dwell you need to learn from failure, adapt and move on. At an FRC event you don’t have your shop, you have a limited amount of materials and you need to quickly make improvements to your robot. Below are some of the quick fixes we made between matches.
We added a poly carbonate plate to the battery that is retained with wing nuts. Also in this picture at the front left and right are two poly carbonate plates that prevent cones from getting stuck if our arm moves bounces too far back while moving.
The next major fix we made was adding a strike plate to the back side of the intake. This prevents us from getting stuck on the middle pole while scoring.
We ended the day with 4 wins and 5 loses and were ranked in the mid 20’s. This made the scouting meeting short, we shared stories and compiled a list of possible 3rd pick robots so we could contribute if we were picked by an alliance.
Saturday
Our goal for Saturday was simple, score as many game pieces as possible and create some momentum. I find once you have some momentum at an event you can snow ball and increase your teams performance. If we did well enough we might be picked early by teams who are doing last minute scouting.
We had three matches on Saturday and we managed to pick up 2 wins. In match 62 we scored 6 game pieces, and in match 72 and 78 we scored five game pieces. The drive team managed to create some much needed momentum for the team and carried it into play off matches.
The team ended up being picked by 7th seed Alliance captain’s 4610. We lost our first match in the double elimination tournament, won our second and lost the third match. Another Austin team 2881 Lady Cans who knocked us out in the third match went on to win the event! Super excited for them!
Overall double elimination tournament was great, there was plenty of time between matches to fix issues and it was nice having another chance after losing to the second seed Alliance. The one problem was that it was hard to figure out who your next match was against and what color bumpers you needed. I’m sure we’ll figure it out in a few years.
Small Problems
In the first .gif posted there were two problems, you can see the intake slightly bounce off of the middle pole and the battery breaks out of the velcro strap as we go over the cable protector.
The big lesson we learned here is that it is easy to ignore/put off small problems you have while at home. In the final days before our event we were busy focusing on larger problems and didn’t focus on what seemed to be small problems. We did attempt to fix the battery strap problem but didn’t have time to get the fix on and verify it at home.
What seems like a small problem at home can and will become a large problem once you are on the competition field. You don’t get a second chance during a match and they certainly don’t let you pause the match and strap your battery down again. Don’t ignore small problems that you manually fix or reset while testing your robot, you don’t get the chance to do that during an event!
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Day 59
Today was the first meeting after the Waco district event, we have a routine that we do after every event. First we start with story time where the team shares funny, unique or surprising moments. Next we do a blameless postmortem where we talk about things that went well and things that went poorly. The blameless part is critical we are not looking to assign blame for failures but looking for ways we can improve our process.
If you read the recap post most of the items mentioned were covered there. Some new items in the went well column are food choices, team spirit, and pit setup quickly. Some new additions to the went poorly list trailer leaks, canman(mascot) needs more ice and robot cart needs new wheels.
CAD
The second joint of the arm is getting some rapid fire improvements before our next event. The second joint is currently powered by a winch(upwards) and gravity(downwards). This worked okay at the first event but had a few slight problems. We didn’t enjoy coming to a sudden stop and our arm raising outside of the robot. This got a few G204 fouls. Another problem happens when approaching a game piece the arm can swing out from momentum or be pushed up by the game piece.
This makes it slightly harder than it should be to quickly intake game pieces. So to fix these two problems we are changing the second joint of the arm to be driven by a chain on a dead axle. This also makes the arm slightly easier to control from programming’s perspective. The down side is that this adds more weight(that is decently high up) on the robot. So to balance it out we added a lightening pattern to the first stage arms.
The CAD sub team is also working on adding all of the pit fixes we did at Waco to the robot. We need to add the cone node deflector, top cover, battery strap and add a cube retaining strap to the intake. Thankfully our next event is week 4, we have time but that doesn’t mean we are going to slow down we want to get all these changes made this week to have more time to iterate on the next additions.
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Day 61
Its been a bit of a slow week for the team, everyone is recovering from competition at Waco. That hasn’t stopped us from releasing the chain driven iteration of the arm’s second joint.
The new chain powered arm has two idlers at the top so we can route the chain inside of the arm’s poly carbonate covers. This prevents the chain from destroying our sponsor plate. The chain version is .1 seconds slower than our current winch iteration, it is able to rotate 90 degrees in .549 seconds. But it is able to be powered backwards and should be able to lock and hold a positions better.
All of the parts for the chain powered conversion were released to manufacturing late last night. Manufacturing has been busy assembling our second robot so we can increase our iteration speed and give programming(and drive team) more time on the robot. The second robot uses the practice swerve drive base. The choochoo gearbox is mounted to the drive base and the arm was fully assembled last night. All that is left is to finish up the intake and mount them both to the practice bot.
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Day 63 and 64
Over the past two days we’ve been working hard to get both robots up and running. The practice bot got its arm and intake attached. Tonight it’s arm ran for the first time. It took longer than desired to get everything working because we had to clean up messy wiring along the way.
The practice robot with the buddy carry attached.
The buddy carry was finally tested today with a the full weight practice bot. Unfortunately a video wasn’t recorded. I’ll try to get one on Tuesday. I heard it didn’t work well and had problems with balance and keeping enough weight on all four swerve modules. It struggled driving up the charge station. It does look cool though.
Today we took the competition robot down for an upgrade. The second joint’s chain conversion had all of the parts manufactured and we were ready to put it on a robot. The chain gear box was assembled and mounted to the arm. The lightened arm rails, top joints and idlers all got put on the competition robot. We’ve still got to re attach the poly carbonate plates and hook up the wiring but we are closer to having the chain upgrade ready to test.
There are a few changes for the arm’s programming involved with the chain upgrade but if everything goes well we can start testing / using it on Tuesday.
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Day 67
The chain conversion on the second stage of the arm finally got all the way put together. It was slow going because we had to resolve some clearance issues that were missed in CAD. Now there is a new problem with the gear box, it flexes a lot when powering the arm down. Watch the Neos closely you can see the flex.
CAD has already released a fix which adds two plates, a bearing to support the output shaft and extends the output shaft. With only two shafts and three plates to make we should have the upgrade ready to put on the robot by Saturday.
We noticed the flex when we were tuning PID on the arm. It was happening while the arm was very poorly tuned. The flex might not be as bad if the arm is well tuned but we want to solve this problem now at our shop rather then during competition.
Now that the arm has a chain(and isn’t controlled by a winch) we can calculate static gains to use with feed forward control. Programming got this added to the arm, feed forward makes the PID easier to tune which results in a smoother moving arm. Next up we have to tune PID on the second joint and because the arm got .5″ longer we have to find all the new key positions of the arm.
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Day 70
Today we tested the cube catapult after we got all of the pieces made. The results were interesting.
The original idea wasn’t to launch the cube over the robot, but off the back side. But that didn’t have enough power. Over the robot didn’t work that well either, consistency issues and the cube goes too high so it bounces out of the node. The CAD team went back to the drawing board and came up with this?
The cube puncher worked well enough that we added pneumatics to the robot for further testing.
The parts to fix the chain arm flexing and chain tensioner were completed today. Its not the best looking gear box we’ve designed but it works and it was able to fit on the existing arm.
Next the robot was turned over to programming and they set off making the arm fast and well controlled. Both joints are at a good spot now, they are moving faster than we ran at the last competition, and there isn’t a winch for the second joint. Tomorrow we’ll try testing it out on the field while moving and see if it can hold positions more accurately.
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Day 73
Quick update from last night, we added an inline chain tensioner to the arm. This makes adjusting the tension of the chain super easy.
Next we replaced the top sprocket on the chain stage that was looking pretty rough. The sprocket teeth started to look like shark fins. One of our through bore encoders that we are using in absolute position mode on the second joint is giving us slight troubles. It seemly lost it’s zero last and we had to re-calibrate the second arm’s joint.
To end the night we found a missing tooth and more shark fins on the bottom smaller sprocket on the second stage of the arm. We are hoping that a lot of this wear was from when the chain was loose and skipping. The arm has about 8 hours of run time on it, so worst case for now the sprocket might end up being a consumable for our next event.
Tomorrow is filled with auto testing and some drive practice to end the night. Thursday the team leaves for the Houston District Event.
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Houston District Event Recap
Going into the Houston District event our team had one major goal, secure enough district points to make it to District Championship. The estimated number of district points to safely reach District Champion ship in Texas is about 56 points. At our first event we ended with 21 points, so we needed to get 36 points to secure our spot.
One possible path to earn 36 points district points is ranking 1-8 (~15 points), being alliance captains or getting picked by rank 1 – 6( ~13 points), reaching match 13 in double elimination (7 points). This was just one possible way we could secure our spot to the District Championship.
Problems
The first problem didn’t actually happen at Houston but happened during play at Waco. The problem happens when we feed game pieces in through the single sub station. During the Waco event we dropped the cone and drove up towards it, our intake facing the opponents driver station. This makes it almost impossible to see what is going on and we didn’t always know when we had securely grabbed the game piece.
There was this CD thread and suddenly our life got easier. At home we practiced this and we implemented this strategy during the Houston event. Amazing how effective such a simple change can be.
During our second practice match we ran into our first problem at the event. One of the Neo 550 on the intake died. We were still able to intake cones but we couldn’t intake cubes. The solution was simple, we replaced the burnt out 550 and did a systems check.
During the systems check we noticed a rather large problem, the gears in the choochoo gearbox were slipping past each other and the first stage of the arm couldn’t move all of the way. The source of the problem? The hex shaft on the final stage of the choochoo gear box. This stage contains the wheel which attaches the linkage to the arm.The shaft looked like this.
We couldn’t get the shaft out in one piece and we had a qualification match coming up in the next few minutes. To temporarily solve the problem we rotated the shaft 180 degrees and re-attached the choochoo wheel and linkage. The shaft was bent in such a way that this temporarily fixed the slipping gears and we were able to play our first match with the arm working.
The shaft was replaced after our first match. The shaft that bent was hollow and made out of 6063 Aluminum. This shaft has been on the robot for the entire season going through many hours of practice and just failed now. We replaced the shaft with a solid one made 7075 Aluminum, hopefully this will last us the next half of the season.
The next problem appeared after replacing the choochoo shaft. The robot started having problems during the high cone score sequence. It was unable to score cones on the high nodes.
It took us 6 matches to solve the problem. During those six matches we scored on the middle nodes and low nodes. The solution ended up being pretty simple. Another point was added to the high score sequence, this point results in a movement that only lowers the second joint of the arm. This sets the cone onto the high node before the base arm moves back to score.
The high scoring sequence problem only appeared after we replaced the choochoo shaft. We think the shaft was bent for a while and this slowed the choochoo gearbox’s movement down. The high score sequence was tuned to work with the slowed movement. Replacing the shaft removed the resistance, speed the choochoo up and our scoring sequence no longer worked.
I’m happy to report that during the Houston Event we didn’t have any match ending problems. This was a giant step up from our first event. There were problems, but we managed to play through all of them and continue scoring.
Outcomes
Friday was a cycle of fixing small problems, playing matches and watching our match footage to find small improvements.
The results showed at the end of day, we were ranked 7th. Our scouting data had us doing an average of 6.1 game pieces per match which was the 4th highest at the event, we were a bit lower on teleop score with an average of 17 points or 6th highest. Here is our team’s scouting data from Houston.
Scouting Meeting
Saturday we had two qualification matches and we managed to win both, we ended qualification matches at rank 5. We were excited to invite 5414 Pearadox, 4332 EHS RoboCats and (eventually) 7312 T3 to play with us on the number 4 alliance.
Our alliance managed to win every match in the upper bracket and we found ourselves in the finals playing against Alliance 1 composed of 118 Robonauts, 3847 Spectrum, 2585 Impact and 9121 Wild WEST. This was an incredibly tough match up. Our alliance managed to bring it within 9 points in Finals 2 but we ended up losing to Alliance 1.
It was amazing getting to play with our all of our great alliance partners! Congrats to all of Alliance 1 for a well deserved win! Our team took home two awards at the event, Event Finalist and Industrial Design Award.
Fun Moments
Our prototyping fail* video got played during one of the breaks. Apparently it also was played at more events as one of our students saw it while watching the Sacramento Regional.
** There are no failures during prototyping, only lessons about what does and doesn’t work.*
The Teams Reaction To Seeing Our Video, Drive Team Clueless
We didn’t set the right autonomous mode and accidentally did a double balance during auto.
This tradition is going to continue for a while.
Baby Can Man
Final Notes
Our goal for the Houston event was to earn enough District Points to make it to states, a combined total from each event of 56. Well at Houston alone we earned 56 District Points, our total for the season is 77, enough to secure a spot at District Championship. Looks like we’ll be going back to Houston!
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Bumper Mounting System
My team uses a spring loaded bumper latch to secure our bumpers. When the bumper is pushed down, it is locked in until the release lever (the tall thing sticking up) if flicked.
The bumper latch unlocked.
The bumper latch locked in.
In addition to these, we used some slide-in dovetails to further support the bumper. This was also done to support it per 8" according to bumper rules. The holder is bolted directly to the frame-rail while the slider is connected to the bumper plywood. Both of these pieces are 3D printed PLA at 45% infill and 6 walls. The holder breaks occasionally but not often enough to be a problem.
Picture of dovetail support
We also use 3D printed corner brackets to further support the bumper. This reinforces the bumper corner to the frame, which reduces the lateral forces on the other mounting components.
Photo of bumper corner
Final bumper latch
The lever was originally much smaller (see below) but it was changed in order to easier access them next to the bumpers. The lever was also originally PLA but would break under the upward force of the bumper, so it was later changed to polycarbonate. The front plate of the latch is aluminum in order to bear the load of downward force on the bumper.
The small lever.
The pin is a 1/4-20 bolt with an aluminum spacer attached. The spacer was originally 3D printed but was unreliable so we switched to aluminum. The pins and dovetails are attached to the bumper by T-nuts in the bumper plywood. The mounting holes are patterned to allow for flexible placement of the bumper latches and dovetails.
T-nuts inside of bumper plywood.
The full constructed bumper latch.
The spring is cut down and bent to fit into the bumper latch and lever, it is not used out of the box (see below)
Picture of bent spring
Picture of where the spring goes in the back plate
Bumper Latch CAD file: Onshape
Link to spring: McMaster-Carr
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Day 81
How many dropped cubes is too many?
One?
Two?
Three…
Okay three is too many, I stopped trying to find more at this point. These are just from our play in the elimination tournament at Houston. We have a cube scoring problem.
Our arm is capable of reaching to many different points and could easily have a cube scoring location. But our driver controls every action of the robot and we don’t have any free buttons to cram another item onto them.
The intake has had mounting holes for two time of flight sensors for a long while. The sensors we actually on the robot for Houston, we were just missing the code to make use of them. We are using two of these on the intake, they are connected to a pico pi and communicate back to the Roborio over serial.
Today we got the time of flight sensors integrated into our robot code. When the top time of flight sensor detects a cube in the intake the arm goes to a cube high or cube mid scoring position(depending on which button the driver presses). Hopefully we’ll be dropping a lot less cubes at District Champs!
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Day 84 & 85
Things are slowing down here as we prepare for District Champs. The team has been working on some cleanup of CAD, a few small tweaks to the cube launcher, and starting to prepare for off season training. Oh we’ve been using the robot a ton too, getting hours of driver practice and autonomous tuning in.
The cube launcher was on the robot at Houston but we didn’t have enough time to get it integrated into useful autonomous modes. Well the programing team has made great progress over the past week and we have a new 3 cube autonomous routine!
They’ve also upgraded out auto balance routine, we now grab a game piece on the way to the charge station.
Initially we were trying for a High Link autonomous routine but we ran into troubles. The margin for error with placing a cone is just too small. We are a long way away from having a way to localize our position and correct for any errors. It is much easier to score and intake cubes. So it was decided to implement a 3 cube autonomous routine for District Champs.
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District Championship Recap
The load in team got to Houston on Thursday. This year DCMP was held on the 3rd floor of the George R Brown Convention Center. The trailer got suck in traffic and the long line up the ramp to the third floor. We eventually got the trailer unloaded at 7:10 pm and just managed to get the pit setup before the pits closed for the night.
Thursday got off to a rushed start, we had to get inspected and fix an intake motor that we broke on Tuesday before we left the lab. Inspection went smoothly and we fixed the intake motor. The pinion on the ultra planetary wasn’t pressed onto the shaft far enough. This was causing the ultra planetary stages to bind when it was all tightened together.
Thursday of DCMP always has an odd feeling to me. There is a good chunk of time for practice matches which we try to make the most use out of. Then at 3:00 pm qualification matches start. I find its hard to switch into competition mode that late in the day.
Fortunately the robot was rock solid for district champion ship. Turns out we ironed out most of the kinks at the Waco District Event. We were able to play the entire event without any match affecting break downs. Stuff still broke though.
Failure: The back poly carbonate intake plate broke during out last practice match before lunch. We didn’t notice until we were back from lunch.
Fix: Attach spare intake plate
Failure: Shoes Broke
Fix: super glue
We also broke a few bumper dove tail mounts, these in there current iteration are sort of consumables. The dove tails need a little more reinforcement so they stop breaking. The bumper mounting system got a lot of fan fare at DCMP. We plan on making another iteration that will make changing out the parts even easier and slightly stronger dovetails.
Eventually the qualification match schedule was released and we dived into it. Our match schedule was good and it was up to us to make the most of it. We had a stacked alliance in qualification match 22.
Cube Shooting Buddies
During this match our alliance filled the grid. We put up the last piece at 20 seconds. I was looking at the grid for an empty spot and couldn’t find one. It was fun/strange feeling of having nothing left to do in a match. This match set the event high score of 182 that lasted for a few rounds.
Adding the Last Piece
Through out the qualification matches on Thursday our 3 cube autonomous was very hit or miss. We struggled picking up the two cubes on the staging marks. In the our shop we had been able to hit 3 cubes reliably. We used Advantage Scope and close up match videos to attempt to debug the problem.
Using Advantage Scope it is possible to sync up video and match logs(such a great feature!!!). We used this to change up our cube positioning slightly and we were able to score at least one additional cube the majority of the time.
We played through the majority of our qualification matches and were sitting around rank 12 on Friday night. At our scouting meeting we came up with a list of picks. You can find our scouting data for the event here.
Saturday we had one qualification match and it was a match we needed to get 4 RP from. Our alliance played amazing and we got the 4 RP. This moved us up from 12th to 8th and gave us a lot more freedom and options.
With our win we moved up to 8th seed and ended up as the 7th Alliance Captain, forming an alliance with 6357 The Spring Konstant and 7616 Cerberus. Our first elimination match was against the 2nd alliance 624, 148 and 4192, this was a hard match and we dropped into the lower bracket. We won the next match but were unable to win our second match in the lower bracket and got knocked out. It was great playing with our alliance partner ya’ll played great!
Wrapping Up
District Championship was our team’s last competition of the season. During the season we gained a total of 158 district points, the final cutoff for making it to Worlds was 176 district points.
I’m incredibly proud of our students for what we have accomplished this season. We’ve made some great friends, competed against the top teams in the world and are looking forward doing it again next year. Fun fact this year was the majority of our team’s first time experiencing an FRC build season and competitions.
It may be the end our our season but I have a few more posts that I want to write about things that went well this year, but don’t expect any major robot changes or upgrades 
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