Team 3926 MPAror Robotics 2023 Open Alliance Thread

Doesn’t this alliance station have a Plexi flap that would prevent an upright cone that is sliding to be knocked down as it was travelling down the chute. I think this would cause the cone to slide base-first at your mechanism.


Yep, it seems like it would. After some experimenting this morning, we actually decided to ditch that idea altogether as from the field tour, and our field elements we have, it seems like the cone won’t have a super hard time landing upright on the floor, and not making that mechanism (instead a simpler for bar for extension/retraction of the intake), would allow us to spend more time on a potential cone uprighting mechanism (although this isn’t top priority).

1 Like

Tuesday, 1/24/22 Update

An update by me earlier than midnight!?!? I must’ve fixed my sleep schedule or something (or I’m just procrastinating my homework, I’ll leave it as an exercise to the reader to determine which is the case).

We have only met for 2 days since we last posted an update but we have made quite a bit of progress since then.

First, we have started construction of the drive base. Our Evo Shifters and Pneumatic wheels arrived last Friday, and we cut the remaining pieces we needed to on Saturday for the drive base. We assembled the frame, but realized that we had the incorrect wheels for the front and back. The pneumatic wheels we ordered had hex hubs on them, which are the correct ones for the middle wheels that go on the output shaft; however, we need wheels with a hub to press a bearing for the front and back wheels. The correct wheels were re-ordered and will arrive Wednesday so we will fully assemble the drive base then.

On Monday, we began the four bar linkage. The arms of the linkage were cut out of polycarbonate, reamed, and had bearings pressed and we will begin construction of it on Wednesday. The mounting bar to the robot and to the intake will be cut out of aluminum Wednesday, and we’ll begin assembling them together over the next few days. We changed the 4 bar from being able to intake from the chute to only being able to intake from the ground, as we decided that that would be faster, and have a lower CoG. The 4 bar will be actuated by two pneumatic pistons of different lengths attached to each other, giving us for different positions it can be in (11, 00, 10, 01). Our three primary positions will be stowed, intaking, and shooting (to get cubes to higher nodes). We may use the fourth to get a different angle between High and Mid Node Cube Shooting.


We combined our cube intake and cone intake and cut it out using polycarbonate. The cone intake is in the middle/inside and the cube is on the outside. We used the same methods of obtaining the game pieces. We first assembled it with NEO, and then switched to Neo 550’s on there with a 10:1 ratio (Which is what we will be using on the actual intake) We discovered that with this configuration and the right angles and speeds, we should be able to shoot cubes onto the mid and high nodes (as you can see in the video). A downside to this configuration is that, if run too fast, the cubes will get squeezed into the space for the cones and then pop out when the green compliant wheels are no longer being powered as the wheels expand out to normal size.

That’s it for this update. As of now we seem to be on track for the robot to be mechanically complete by the end of week three. At that point it will be handed off to controls and drive team while build/design continue to iterate on the mechanisms. On one hand, I’m incredibly excited for controls to get the robot 3 weeks earlier than any other previous year, on the other, well, it looks right now like I’m on track to be showing off some team spirit up at Northern Lights Regional…
(all team members participating voluntarily signed up)


1/29/23 Update

I would like to recognize that all of my previous posts have been labeled with the year 2022 rather than 2023. Yikes its taken a bit to get used to the new year :sweat_smile:.

With that being said, as of last night, we have a robot! The pneumatics still need to be hooked up and tested, but as of now the drive base and intake is working, and the wiring of the robot is complete.

Here is a video of it going: (clicking the image will take you to videos on our flickr page)


As of right now, our robot drifts to the left while driving straight, so we will have to fix that on Monday, as well as mount the pneumatics.

On code team’s side, we are overjoyed to have a robot to work on three weeks early (at the small price of blue hair) and have learned a few things as well. By setting a very low stall current limit on the intake motors (about 3 amps as of now), we are able to keep our game pieces held in without browning out and burning out our motors. We’ve also been mapping out the autonomous code options we will want:

This week we’ve made a ton of progress and we can’t wait to make more next week (and can’t wait to share the robot driving 19ft/s over the Charging Station!)



Update 2/5/23

Since our last update the vast majority of work done has been on electronics and code with them working on cleaning up and fixing everything. We had electronics mounted last Saturday, but that was missing all the pneumatics as the correct pistons had not arrived yet. The correct ones came in on Monday and were mounted Wednesday and tested on Thursday.
Over the week build continued to work on field elements, bumpers, and made a few fixes that were needed on the robot like covers for our gearboxes to prevent wires from feeding into them. We also started work on redesigning the four bar linkage to increase strength, along with an intake modification in which the front arms would move in and out to pick up tipped cones. We will cut it out during this week and will see whether it is work us continuing with that idea or sticking with our current intake design depending on how well it works.

Controls: Code team has continued to work on our autonomous code, as well as work on programming a CTRE CANdle, which will allow us to signal which game piece we want to our human players via LEDS.

Electronics meanwhile plumbed the pneumatics system and reworked the wiring to make it much neater. On Saturday we encountered an issue (Rev PH not turning on compressor when code previously worked and CAN loop is functional) with our PH that we have yet to resolve. We believe it most likely has to do with an error made when rewiring the CANbus and will investigate more on Monday.

1 Like

An update on this: At the end of lab hours today we were able to get the compressor running! (This update was written yesteday) The culprit? A faulty wire on the 120psi switch.

1 Like

Update 2/9/23

We finished up our redesign of the four bar linkage on Wednesday after a few day of working on it. Our primary goal with this redesign was to increase the strength of the mechanism as we had a few points weak points in the last iteration. Fixing these problems involved double stacking the polycarb plates that connect the intake mounting bar and the drive base mounting bar.

The two mounting bars were also totally redesigned. Starting with the bottom one, it is now one continuous block that will be machined out of aluminum by one of our sponsors. Previously, we had two 3d printed parts, one that attached to the front drive base bar and one that attached to a cross bar. Now this continuous bar is significantly stronger and is attached to the front bar of the drive base.

The new intake mounting bar will also be machined out of aluminum by one of our sponsors, this new bar is attached to the rest of the 4 bar structure on both sides and is significantly stronger than before. It will attached to the intake as the same way as before with a piece of 2x1 going across In front and the intake mounting in the 2x1 bar.

Moving onto the intake, it has had a few modifications. We designed a version of our intake that would have the two front wheels actuate in and out with pneumatics to pick up tipped over cones. With the arms our, the intake functions like our previous iteration, but with the arms moved in the intake wheels would then be able to go inside the bottom of the cone and pick it up. We have not started to cut it out yet as we are unsure if we want to move forward with it as the added pneumatics would be more of a plumbing challenge for electronics and would necessitate another air tank. We will decide whether we want to move forward with this idea soon.

At the same time as this work, we also did a quick redesign of our current intake with a few changes we wanted to make. Those include a deeper well behind the cones, moving the motors back to a more protected area, and creating mounting plates for our motors so it is easier to take them on and off.

The build team will then work on cutting this out and assembling all this, along with assembling our second drive base over the next few days.

Now for some video of our robot doing stuff!!

Due to some spacers on the 4-bar’s pistons, the angle for shooting is not as high as it will be on the final robot. This gives us an angle less suitable for high goal shooting, but one that works for shooting into the mid goal for now. The final robot will be able to do both.


Seen below is a gif of us picking up cones from the Chute. With our current intake iteration, we struggle to pick up cones against the wall area due to the cube intake. In our next iteration, we will make the cube intake closer to the cone intake to alleviate this.



One of the strategies we set after kickoff was that, as a non-swerve team this year, we wanted to be able to differentiate ourselves from a swerve drive by being able to cycle over the charging station without losing time. Now, I present a robot traveling almost full speed (20ish ft/s) with 8 in pneumatic wheels driven into a Charge Station:


Suffice to say I think cycling over it will be fun.


Well i will be watching your matches closely… i would love to see this in a match… :eyes:


It’s week zero already!?!? sound the alarms!!

Daily Update 2/20/23
Wow it’s been a bit since our last update. Things have been quite busy over in our lab preparing for our week one regional in Duluth! With only seven days to work on the robot before we head out, and a massive winter storm heading Minnesota’s way to mess everything up, we’ve been in full steam ahead. Build has been busy working on our competition bot (which, while I’d love to talk about, I’ll save it for them to show off the design changes in an update they’re planning to write about tomorrow).

Meanwhile, code team has gotten a working 2 cube auto that engages the charge station. Originally we were not planning on running this until our week 4 regional at North Star, but during week zero, we discovered that, because our intake stows at a slight backwards angle, we are able to shoot cubes behind us, allowing us to outtake from the opposite side in which we intake. When running this auto without balancing, this allows us to score both game pieces in the grid, with one scoring on the middle tier (and possibly the high node with the intake modifications being made for robot v2) and the other in the hybrid node. When balancing, wether or not we get two cubes scored is more of a crapshoot. At least one will score in the hybrid node, and the other will bounce when shot, hopefully into an empty node. If it doesn’t, it can be pushed in and scored in tele-op relatively easy. The reason for this is that the Cube nodes don’t line up as well with the pre-staged game pieces, meaning we will be shooting and hoping the second cube pachinkos it’s way into a score. If it doesn’t, we lose one point and about 5 seconds, which isn’t the end of the world (and it certainly beats a one cube auto!)

Here’s a video of it in action (although of course the one we video taped is the one where we reset the cube incorectly haha) (1)

Now for our Week Zero Recap:
This Saturday we attended the Blue Twilight Week Zero Invitational at Eagan High School, graciously hosted by team 2220 (The entire event was great and ran super well – thanks for hosting!). After working through some mechanical breakages and radio troubles in early matches, things went pretty smoothly. We also, as alluded to above, discovered we were able to shoot backwards. This came about because, there was a small leak in the pneumatics system that we were unable to detect before one of our matches was scheduled, so we were unable to deploy the intake during autonomous. Instead, we shot it backwards onto the charge station, and then drove over it, popping in in a very tragic fashion. We did however, realize that the cubes could be shot far enough to be scored backwards, which enables us to score more in both teleop and auto.

Another struggle we faced was the dreaded tippy robot syndrome. While we believed a robot with a low CoG like this one to be untip-able, we defied the odds when reversing after cycling at top speed. We have made a fix to ensure this does not occur again. Below is the glorious footage of the tip however – it was quite funny when it occurred (imagine the wii sports bowling “ohhhhh” sound effect with Sandstorm by Darude being played as audio over the gif)

Our best match was our final one, seen in this timestamp on the livestream:

Overall we scored 6 game pieces, leaving 30 seconds to climb. This is well on our way to our goal of 9 cycles/match, as with more driver practice, the 2 game piece auto, and climbing closer to t=0, we will be increasing our scores. I can’t wait to see what comes next for our robot at Northern Lights regional next week!


A quick build update of our robot

We have started (and are almost complete) with out second drive base which will be the robot we bring to competition. We have the electronics board mounted, the gearbox and motors, and one side of the wheels attached. We will hopefully finish it up today.

I have already outlined the changes to the four bar we made in the update posted on February 9th.

As for the intake, we decided to stay with a static intake for Duluth, but we made a few changed to improve it from our current intake.

The motors were moved all the way to the back of the intake to protect them more, we slightly moved the front wheels closer to increase compression, and we added a curved backstop for the cones to hold them better. This intake will also be cut out of polycarbonate we now have the stock to do so. We are also using Neos instead of Neo 550s to get more power so we can shoot game pieces. We have been successful in shooting cubes, which we did a few times at week zero, but have not found any success with shooting cones.

We will work to assemble this second robot as quickly as we can so the coders can make any adjustments needed with the new robot, and with lots of snow on the horizon we will be working extra hard over the next week.

1 Like

The backstop being curved should also hopefully help with shooting cones. It is inspired by the intake on team 7028’s robot, which can be seen here: No Elevator / No Arms - YouTube

Well, it’s official, we have no school tomorrow and thursday…:confused: …plans incoming.

Update 2/28/23
T-Minus 24 hours until we leave for Northern Lights Regional in Duluth.

We are rapidly approaching our first regional of the season! While the 2 snowdays may have set back our progress a bit, we quickly got back on track and are ready with our competition robot.

While build was assembling our main robot, code and drive team took our practice robot out and made a reveal video! You can find it here:

With that, final preparations are being made, and packing has begun for Duluth. We can’t wait to meet our competition there! And with that, good luck to all teams competing in week 1!

Update 3/4/23

Holy crap what a weekend it’s been. I think it’s safe to say that we did not imagine it going as well as it did. It had its ups and downs throughout but I think everyone on the team can say it was a success. We ended up on the Finalist Alliance as well as winning the Judges Award! This is our first regional playoff appearance since 2019, and our first award since 2014, in nearly 10 years. Suffice to say our efforts this year have paid off. The rest of the post will be split into two sections, the first focusing on our qualification matches, and then the playoffs.

Thursday/Qualification Matches:

During inspection, we learned that you only need one regulator for all your solenoids and a system. We originally had 3 plus a system because we thought that all the solenoids would need a regulator. We also had a problem with keeping our compressor wires in the pneumatic hub, we ended up just zip-tying it, it would stay in the perfect place, but we still need to fully fix that problem.

Throughout our qualification matches we had a slight challenge intaking cubes. If we were not aligned well, cubes would be knocked away and it was especially difficult to pick them up in autonomous if we were not perfectly aligned. This problem did not completely cripple us as we were still able to pick up cubes, but it took longer than we wanted. We primarily resorted to picking up cubes against a wall in the loading station, and as the matches progressed we got better at picking them up in the open field. We also reduced the speeds the wheels spun at on Saturday morning, which also helped.

Before our next competition, we will experiment with new wheel speeds spacings and different sized wheels. The intake on our robot compresses the cube .5 inches more than the previous version of the intake. We did this because we were having problems holding onto the cubes at week zero. Over the next two weeks we will experiment with decreasing the compression back to the previous distance and seeing if we still have the problem that we had at week zero, and using smaller wheels for the cube part of the intake to see if the smaller wheels will decrease the amount of movement the cube has because the surface will be moving at a slower speed, as well as looking at if adding some star wheels in the stack could help. We will also try swapping out pullies to see if putting in a reduction to slow the front wheels. We will also keep exploring changing the wheel speeds to help our intake.

Despite these problems, we were still able to cycle quickly and ended the competition with the most cubes score per match and the 7th highest total game pieces per match.

In our second qualifications match, our drivetrain motors were set in brake mode, rather than coast during teleop. We were using brake mode in auto for our balance to be more consistent consistent, but in teleop this compounded the already large problem of a fast and tippy robot worse, causing us to tip over. We hoped that a code fix that allowed the mode to be toggleable would prevent future tips from occurring. Unfortunately, this toggle was later accidentally switched on during one of our playoff matches, causing us to tip again. A more long term solution is being looked into for the code, including a slew rate limiter for deceleration and potential controller rumble to signal to our drivers when we are in brake mode.

Tippy qual match:

In two matches, one, Qualifications, and the other a playoff match, we lost pneumatic pressure. A tube had popped out of its connector, we had pre-pressured before the match and the pressure had stayed until the robot got on the field. We think a tube popped out because it had too much strain on it, and it didn’t have enough slack to move around. The simple fix we made in the moment was just to put it back in, but that did not work long term because the same tubes would continue to pop out. We later learned that if a tube pops, to replace it because it’s probably damaged on the ends and has changed shape. Overall, for our team using pneumatics for the first time since 2016, we only had a few hiccups and learned quite a bit about how to make our system more reliable in future competitions.

Playoff Matches:

After alliance selections, we ended up as the second pick for the number two seeded alliance, alongside team 5232 Talons and 2987 Rogue Robotics. Early in our strategy discussions it was determined that any two of our robots alone would not have enough firepower to win matches, so we would have to play triple offense. This was because, in our alliance, the amount of points scored each match was distributed about evenly, so losing just one robot for defense could have a large and detrimental effect to our overall scoring output. We ran this strategy all the way to the finals, but unfortunately even with 3 robots cycling we could not match the scoring output of the number 1 seeded alliance, although in finals 2 we came close.

Overall, our weekend at the Northen Lights regional was a success! Huge thanks to our alliance partners 2987 Rogue Robotics and 5232 Talons for being great throughout the playoffs! Y’all were incredible to play and strategize with!

1 Like

At our debrief of the Northern Lights regional that we had today, we designated 3 key areas in which we wanted to improve by coming up with problem statements to solve before our next competition at North Star @ LX:

  1. Our robot can be hard to control

    • More Drive Practice

    • Prevent Robot from Tipping Ever

  2. Our intake pushes away cubes when not accurately running into them, and does not have enough power to shoot to the high goal consistently

    • Test different intake wheel and speed combinations to achieve desired results
  3. The pneumatic tubing on the robot can pop out, causing our autonomous to run in high gear, attaining many fowls

    • Secure pneumatics better

    • Possibly run autonomous mode in high gear, the mode the robot defaults to

    • Be able to detect what gear the robot is running in during autonomous

Update 3/9/23:

We met in person for the first time since Northern Lights yesterday and got to work at our problem statements that we made. First, to address the tipping of the robot, we implemented a slew rate limiter on the robot. This worked in preventing the robot from tipping, over multiple tip tests.

While getting drive practice getting used to the new coast mode and slew rate limiter, the rest of the team discussed potential solutions to our intake problem. Newton’s laws say that we have to be able to touch cubes on both sides to be able to intake it, or it will just be pushed away (or something like that, @AJT an actual build person can probably explain it better). A potential solution we discussed was to add something like the star wheels found at andymark, which could help vector cubes into the center of the intake. We would have to make our own, however, as our other wheels are also 4in in diameter, and we would need a greater diameter. So, last night, I cadded and 3d printed two TPU 5.7in diameter star wheels.

I am also printing some with a larger diameter to test today (I can’t fit 2 wheels with any diameter greater than 5.7in on my print bed at once, which is why I made the oddly specific 5.7in wheels 5.7in), and we will test those as well if they finish printing before robotics today.

Congrats to Ian on the Dean’s List Award at the NorthStar Regional!

It has been fun following the thread of 3926 this season!

1 Like

Thank you!!! We’ll be posting a North Star recap soon. Regardless of awards, it has absolutely been my favorite regional that I’ve ever been to, for so many reasons.

1 Like

Here’s a long-overdue update on how North Star at La Crosse went! It was by far my favorite regional I’ve ever attended, and the same was true for many of our team members. By this point the entire event was a blur for me, so I am just going to list out the successes and challenges our team faced:


  • Our 1 cube high balance auto worked consistently – at least docked every match, engaged in 14/16 times (one time failed to engage due to suspected lost comms from suspected Christmas Treeing in qual match 6) , more on that later

  • Our pneumatics were much more consistent after switching to Y connectors from T connectors and fully using Tygon Tubing – a flexible form of pneumatic tube. While this did not entirely fix the root cause of our pneumatics system failing, that being the kinetic mounting of our pistons (which as it turns out, like to be stationary), it did fix the symptom of tubes failing in matches.

  • There were no major* mechanical or code breakages on the robot – The robot performed consistently in every match, and was robust. Only one code change was made, on practice day to modify the turning speed of our robot when at low speeds in high gear.

  • Our incredibly talented and dedicated coach/mentor, Mr. Shapiro won the Woodie Flowers Finalist Award!!!


  • We were still facing challenges intaking cubes, often pushing them away. This severely hampered our cycle times

  • At the beginning of Sunday, the bottom plate of our intake cracked. This thankfully had multiple solutions, with us attaching a polycarb splint until we could swap out the intake over lunchtime, and did not impact us in match.

  • The Radio: if you watch any of our matches, every once and a while, you will see the robot get disabled for about 3 seconds before reenabling. We are still unsure why this is happening, although it seemed to happen when other robots fully lost comms.

Overall, the tournament was a great success! We ended up being 1st pick the 8th alliance, with our captain team 2143 and second pick team 3130. Thank you all for being great alliance partners! We ended up getting the upset in our second playoff match, and ended up tying for 5th.

We’re now heading into the offseason! Well, not quite yet, at least for us. Thanks to our performance at Northern Lights up in Duluth, it seems that we’ve qualified for the State Championship on May 6th at Williams Arena! For us, that means more robot updates! We’ll be having a meeting tonight to discuss what exactly we want to change, but for now, here is what has been proposed:

  • …Swerve Drive!!! It is a commonly repeated statement to not try swerve for the first time in-season, so what could go wrong transferring an already completed robot to swerve half-way through a season?! Jokes aside, if we do this, we will be doing it right. Swerve would become our primary focus for the next four weeks, and we would create a working drive base before transferring the guts of our current robot to the swerve base which would have identical dimensions to our current robot. If the construction or coding of the swerve base is not successful, we will not be transferring the robot, and bring the robot to state on the shifting tank. Our team is currently very excited to make swerve drive, and continuing that momentum will be helpful to the team.

We can’t wait to continue working on our robot and are excited for what the future holds in store for the team. It’s been our most successful season in team history, statistically our highest unweighted EPA, a finals appearance, our first team attribute award ever (and first award since 2014!), and our first ever blue banner (thanks to the WFFA)! Hopefully 2024 will be even better! Until then, we’ll continue to update this thread over the summer (although most likely less frequently), until the thread starts up again for 2024. This has been one hell of a season, and I’m so glad we could share the journey with everyone on the Open Alliance.

-Ian Frankel

1 Like