We are a new team to the Open Alliance, and we are looking forward to sharing our progress with you this season! We are a mid-sized team based out of Grosse Pointe, Michigan. We typically have 20-30 students on our team divided into 3 subteams. We plan to share build updates, CAD, code, photos, and videos throughout the season.
This year we will be competing at the Milford District Event and the Macomb Community College District Event.
Each year, 3175 participates in a Trunk or Treat event hosted at our school. We decorate and bring our trailer, and set up a robot demo. Last Friday, we were asked by our school’s student council to set up a robot demo again. In past years, we’ve used our in-season robots and let the kids play catch with the game piece from that year (previously power cells or cargo). However, last year, our swerve drive got severely damaged after running it for over an hour on concrete. Our 2023 robot is also suboptimal for an interactive demonstration as there isn’t a great way to play catch with younger kids. Hence our first major project of the fall: Robot in 2 Weeks!
The goal of this robot is to be as simple as possible. It will have a full-width fixed intake feeding into a full-width feeder and shooter designed for 7" foam dodgeballs. To keep it simple, it will consist of two plates and materials that we already have in the shop. We will mount it to a kitbot drivetrain that we already have assembled, wired, and programmed. This project will be a great baseline for new team members to iterate upon and learn electronics and programming.
CAD First Draft:
Last week, on November 1st, we started official meetings with the whole team. Each subteam is meeting twice a week for training and to get ready for the season. We will update on our offseason projects later on.
3175 also uses the fall to do a lot of our outreach. We come from a PreK-12 school, allowing us to work with elementary and middle school students on robotics. In 2021, we worked with our school to integrate FLL into our elementary school curriculum. Every student from PreK to 3rd grade participates in FLL Discover or Explore in their science classroom. In 4th and 5th grade, students can choose to participate in FLL Challenge and middle school students have the opportunity to join our FTC team. 3175 team members mentor our FLL and FTC teams each twice a week in addition to regularly assisting 4 other local FTC teams throughout the fall.
One of our largest annual outreach events is our Community STEAM Faire which we host with our school. Our second annual STEAM Faire consisted of over 30 booths including physics and chemistry demonstrations, building mini robots, art projects, games, FIRST program demonstrations, and much more. This event gives children of all ages the opportunity to explore science, technology, engineering, arts, and math. This year, the event had over 800 people in attendance.
We had all 5 first programs represented this year at the event. We had FLL Discover and Explore sets on display, an FLL Challenge table set up where kids could program their own robots, and a full FTC field set up where kids could play a human version of CenterStage. Our FTC and FRC robots were also on display and being demonstrated for kids of all ages. Every 3175 team member volunteered at the event and we were so excited to see so many kids experiencing the world of STEAM.
We wanted to provide an update on how we have been preparing for kickoff and our goals for the season before kickoff tomorrow. We spent the last few days of the preseason updating our 2023 robot code to Phoenix 6 and doing maintenance on our MK4i’s. We took the modules apart, cleaned them, and swapped to Colson wheels for the 2024 season.
Our goal for build season is always to have our robot fully built and moving before the end of week 4 of build season. Our first priority is always simplicity and designing a robot that we can build quickly to leave time for iteration. We will outline our design and strategic decisions here throughout the first few days of the season.
We expect to have initial robot CAD complete for a design review within 7 days. The build season schedule we’ve been using for the past 2 seasons is shown below:
The design review date at the beginning of the season is flexible within a few days, but we strive to have parts ordered and design freeze around the middle of Week 2. This allows us to begin manufacturing and have assembly complete by the middle of Week 4. After Week 4, our focus shifts completely to constant iteration and programming.
Finally, our kickoff plan places importance on strategic design and estimating our resources and build capabilities as well as possible. Here is our Saturday kickoff agenda:
We begin by talking about Strategic Design using resources such as 1678’s Strategic Design slideshow to give students a better understanding of what our goal is as we do our initial game analysis. After the game is revealed, we use a slightly modified version of the Shaker Robotics Kickoff Sheet to closely read over the manual in groups. Finally, we list every possible robot action and categorize them by difficulty, before creating a prioritized list of robot functions. This list serves as a guide as we determine what our robot will do over the course of the next few days.
We can’t wait for tomorrow to see what game we’ll be playing in 2024!
Kickoff yesterday went well and we are looking forward to seeing what Crescendo has to offer! We were able to analyze the rules in detail, create a robot priority list, and begin some prototyping with notes.
We decided early on that the best decision for our team will be to primarily shoot into the speaker from against the subwoofer and into the amp from right up against it. One of our design philosophies in shooting games is to shoot exclusively from walls whenever it is strategically and competitively viable. It removes the need for vision and the wall essentially creates a protected shooting spot from defense. We are not entirely ruling out shooting from a second position if it becomes viable later on, but for now, we are designing around shooting exclusively from the subwoofer.
We also decided early on that picking up notes from the ground will be the fastest and most effective option for us. We see resemblance between 2017 gear cycles and full field note cycles. The 2017 meta of gear floor pickup has led us to believe that floor intakes will be most viable in this game. We also want the ability to pick up pieces from the ground in auto.
Here is our priority list after strategic analysis of Crescendo:
So far our designs are leaning toward an over the bumper floor intake because intaking under the bumpers with swerve requires our robot to be much wider and our front frame rail to be less robust than we are comfortable with. We are currently exploring the possibilities of fixed and variable shooters for speaker and amp in layout sketches. CAD is in progress for a few different architectures which we will post once they are more finalized.
We did a little bit of prototyping on kickoff with Notes to get a feel for how they can be manipulated in intakes and amp placement. Here are a few videos of our rough prototypes:
Over the last few days we have continued prototyping with Notes and discussing robot architectures. We did two main layout sketches and after discussing several options, we finally decided on an architecture and CAD is now in progress. This post will explain each of our versions and what went into our final decision. A few notes, we are currently ignoring the trap and assuming we will only be scoring in the amp and the speaker. We’re only prioritizing shooting into the speaker from directly against the subwoofer. We are also planning on climbing, but current DOF counts do not include a climber. Climber designs are still completely up in the air.
This robot architecture consists of an over the bumper intake leading into a feeder with a fixed shooter. Our prototyping found that notes can’t be scored in the amp with reasonable accuracy at the same angle as what would be optimal for the speaker, unless there is something else directing the notes in. The options we considered included a deployable standoff above the shooter that rests against the amp or a short flexible ramp below the shooter. It also doesn’t fit under the stage without adding another DOF. Fitting under the stage is something that is not 100% necessary for us, but we are aiming to find a design that fits under without adding extra complexity. This robot has 6 DOFs, 2 rotational positional and 4 rotational continuous, plus a 7th DOF that is either the flexible ramp or deployable bar. We continued searching for a simpler solution.
This version is inspired by Cranberry Alarm Ri3D and @howlongismyname’s CAD in 12 Hours. It consists of a pivoting intake that leads to a handoff into a feeder and a pivoting shooter. The pivoting shooter allows for a more optimal angle when shooting into the amp and the potential to add shooting from the podium later on. Another benefit is that we could have a single climber in the center of the robot because the shooter is able to create clearance. This fits under the stage in the lower shooter position and has 5 DOFs, 2 rotational positional and 3 rotational continuous. For many of these reasons, we decided to continue with this handoff architecture.
Before settling on a design and beginning CAD, we explored the possibility of using the handoff architecture with a fixed shooter. This would have the same number of DOFs as the double pivot design (one less due to the fixed shooter, but that one is replaced because a deployable ramp or bar for shooting amps is necessary). We decided that the reliability in shooting amps on a downward angle is worth the complexity of a non-fixed shooter.
So CAD is officially in progress using the V2 Double Pivot architecture. We are aiming for the initial robot CAD to be finished for a design review by this Friday. We will update and post our public CAD once more progress has been made - in the meantime, if anyone has any questions feel free to ask!
The first version of robot CAD is officially complete! Our public CAD is here: Onshape
This robot is capable of ground intaking, scoring in the amp, scoring in the speaker, and climbing on the chain. Our tests found that scoring in the trap is extremely difficult and we decided that we will be better off using our resources elsewhere. Ignoring the trap has allowed us to have complete CAD 8 days into build season and our goal is to have this robot built in the next 2 weeks. This leaves us with plenty of time left of build season to iterate and add more capability if we believe it is the most effective use of our time.
Our drivetrain this year is SDS MK4i’s with a 26x26” frame and we plan to use Krakens once they arrive. This robot will most likely be mostly assembled with Falcons that we have on hand and replaced with Krakens later.
We decided to lay out all of our electronics in CAD for a few reasons. First, we have used birch wood bellypans in the past and have had issues with durability. Our bellypan was falling apart towards the end of last season, so this year we decided to purchase a ⅛” bellypan with tapped electronics holes. We debated between aluminum and steel and decided on steel because this robot is already so light and benefits from more weight low for the CoG. We also are very short on electronics space due to our smaller frame this year, so we ensured that everything fit with plenty of space for wires in CAD.
We also designed custom plates to go under swerve modules to keep dust out of the bellypan and made custom 3D printed swerve module covers for Krakens.
This year’s robot superstructure is very simple. It consists of a 2x2 tube supporting the shooter and two standoffs supporting that tube laterally. These lateral supports are one thing that we may iterate on throughout the season. Due to the sideways acceleration that robots now see with omnidirectional drivetrains, our robots have needed more lateral support than we expected in the past few years. Our plan with these supports is to find weak points once this robot is actually built and improve them to avoid future failures.
Our intake pivot is geared 50:1 off a Kraken and has a 0.2 second deploy time and the intake motor is at a 3:2 reduction. We know that this intake is going to have to be able to handle frequent robot to robot collisions at high speeds. Last year we had problems with bending standoffs from high speed collisions so we elected to use polycarb intake rollers because they are more flexible. We made an effort to strengthen this intake pivot compared to the wrist we used last year, and will likely make this stronger throughout the season.
As the intake is retracted, it holds the note with standoffs in the back and completes a handoff to the shooter.
Our shooter this year is on a pivot to allow for more reliable amp scoring. The actual shooter has two front feeder wheels that center the note from our full width intake and two passive polycarb rollers to assist with the handoff. The front feeder wheels and back shooter wheels are geared at a 4:3 step up. For scoring in the speaker, both sets of shooter wheels will spin at full speed and the intake rollers will act as a feeder. For amp scoring, the front wheels and back wheels will spin in opposite directions to hold the note while the shooter pivots.
The shooter pivot is geared 60:1 off a Kraken and has an external CANcoder for more accurate position data.
Our climb is a 3 stage Greyt telescoping tube geared 9:1 off a Kraken. We have 3 stages so that we can package it under our feeder and shooter and we chose to use only one climber due to the uneven nature of the chain.
Today at practice our build team was able to finish hand manufacturing all of the tubes and standoffs that we keep in stock in our shop (everything except a few intake rollers and climber tubes). We have also begun subsystem code which is public on our Github. Manufacturing all of the polycarbonate plates on our Omio is also in progress, although that might take a little longer than we originally hoped as we just found out that our school is closed tomorrow due to extremely cold temperatures.
Feel free to take a look at our CAD, we are happy to answer any questions below!
Build season Week 2 was very eventful! We ended the week with a mostly assembled robot, but we are also encountering a few obstacles. This post will detail what our manufacturing and assembly process looked like this week and how we’re working through some challenges.
During practices early this week we completed all of our manufacturing. Most of the build team worked through our hand manufacturing list while other students simultaneously cut parts on our Omio. All of these parts were finished by the middle of practice Thursday and we started assembling the robot frame.
During Friday practice, we assembled the shooter, shooter tower, and parts of the intake. We continued this momentum to Saturday where we completed the rest of the shooter, intake pivot, and mounted the swerve modules.
This is what the majority of the robot will look like, but we have a few significant things to add:
Here are a few testing videos that we were able to take before mounting any motors:
We’re so excited to (hopefully!!) have a moving robot soon and will be updating our progress in the next few days!
We are doing a similar idea for yours/cranberry alarm. Thanks for posting this! It has been helpful for our team to see how you solved some of the problems we are facing
What is the distance you plan on shooting? Do you plan on shooting from certain spots/hard references?
For now, we are planning on shooting only right against the subwoofer. We are considering adding more distances later if we can score accurately from other places but multiple shooting positions is not a design constraint or a high priority for us.
Today we got the robot running and were able to test a few different distances - a post is coming soon with what went well, what needs to be changed, and plenty of videos.
With the tube rollers how is the note holding up to the compression? It seems like that method would do less damage compared to using some of the compliant wheels that will rip the Note skin.
Obviously hand rolling isn’t the same as powered, but this seems like it could be a winner for not ripping it to shreds.
So far the notes are holding up very well. However, the polycarb rollers are not grippy enough to pick up the notes from the ground as well as we’d like, so we plan to add some sort of grip tape. I will report back after we make that change.
Grip tape or a silicone sleeve? Excited to see this beast at Macomb
We will probably test grip tape first and see how that goes. We’re excited to see y’all too!
edit: sorry managed to hit the wrong reply
We officially have a moving robot! We learned a lot from these tests and found that a lot of things need to change. At the end of this post I will list some important lessons that we learned, many of which have to do with this specific architecture. If your team is using an architecture similar to this one, definitely keep those things in mind.
First and most importantly, when we started shooting into the speaker, we found that our hardstop shooter angle was slightly too low. The notes hit the top of the speaker and miss about 20% of shots due to this. We put the robot on blocks to adjust the angle by about 2 degrees and this fixed the issue entirely.
Speaker shooting video without blocks:
Speaker shooting video with blocks:
We also tested shooting from the side of the subwoofer. This was a little bit particular based on position, but when the corner of our bumper is roughly aligned with the corner of the subwoofer, it works pretty well.
Although we hoped that the first set of shooter wheels would vector the note towards the center of the robot enough to not need our intake to center game pieces, this unfortunately creates too much spin and the notes don’t shoot accurately. This will be fixed with either an automated centering sequence (shown below) or some centering plates in the intake.
Finally, we found that this angle (adjusted by 2 degrees from blocks) works for about a foot back from the subwoofer. Once we change the hardstop angle and get controls tuned in we’ll do some more distance testing.
The one thing that we had no issues with when testing was the amp. Here is a video of our first attempt scoring in the amp:
Overall the intake has a few small and easily fixable issues. First, the intake sometimes compresses the note too far and spits it out between standoffs. This should be fixed pretty quickly with another hardstop that we haven’t fully figured out yet
We also found that polycarb rollers don’t have enough grip on the note, which we somewhat expected. We will do more testing after adding some undecided form of grip tape to these rollers and post videos.
Finally, the handoff from intake to shooter doesn’t work from as many variable angles as we expected it to. We believe this is because the note hits a piece of polycarb between the two shooter plates which slows it down and makes the notes unstable in the air. The front shooter wheels and passive polycarb rollers also don’t hold the note well enough to stay in place while the shooter is moving. Both of these issues will be fixed with new shooter plates in the next week or so.
We spent a few hours yesterday beginning to tune in controls. The shooting sequence works effectively with what we currently have (basic closed loop control) but we plan to add motion profiling on several subsystems once revision 2 of this robot is complete. Our code is always public on our Github, but keep in mind that most of it is unfinished and unrefined. Here’s a video of the robot with a little more automation and closed loop control:
Overall we are very happy with the data we collected from these tests and will report back after this first round of iteration. As always, please feel free to post questions below!
We spent a little while attempting to shoot into the trap and after testing countless positions and angles, we could not get it to successfully land. We have determined trap shooting as currently not worth our time, although if anything changes with robot revisions we will post here.
Trap shooting attempt: IMG_9226.MOV - Google Drive
Written by: Max G., Design and Build Lead
While the climber assembly is in progress (although slightly delayed because one tube was backordered), we wanted to share the modifications that have been made to the climber since the initial CAD was posted. The climber originally consisted of a three stage telescoping tube from WCP. We now have a two stage telescoping tube making use of the parts from the three stage kit. We were able to remove a stage because this climber also has a passive flip up hook that is released by the upward movement of the climber instead of the fixed hook we originally had.
In terms of general robot build, we received our Krakens yesterday and we are currently replacing all of the motors! Over the past few days we rebuilt both the intake and the shooter to fix the shooter angle issue and those should be up and running tonight or tomorrow with new motors.
If you look on the DavidBot video the feeder wheels are separately powered to avoid the spin issue, as well as them being vertical to prevent sideways spin. The issue with this is that it adds build complexity to the shooter but imo it’s kinda necessary for this arch to succeed for long distance.
This is super cool! Could you go over this mechanism a little more? What’s holding the hook in the down position and what’s causing it to spring up?
It is harder to see in pictures, but our feeder wheels are also vertical and separately powered. The horizontal polycarb rollers that you see are passive and they were intended to make it easier to shoot from variable angles. However, we believe that the reason our shots are not going in from further away is because the notes are hitting the polycarb around the feeder wheels and decelerating. We are iterating on the shooter to remove this issue, but we are prioritizing refining other mechanisms because shooting from further back is low on our priority list.
Color blindness hits again. Sorry for not looking at your CAD harder lol.
