Week 3 - Amalgamation

Real practice bumpers look sweet!

No intro for Week 3 - as promised we're kicking straight into design updates! Ok fine, a very quick intro to Week 3. Hello and welcome to Week 3! Three is a crowd, and a lot happened, so yeah, let's jump in!

We had planned to share our design and get a review from some unbiased, external, big robot brained friends this week. (Big brained robot friends? Big robot friend brains? Brained big robot friends? I have to assume one of those statements is accurate...)  One of our designers had a very intriguing prospect, that the current secrecy and hidden plans were simply, exciting. We don't know what we haven't thought of, but other teams out there also don't know what we have or haven't thought of! Everyone gets this amazing surprise at their first event, like a Holiday morning where dozens of robots get unwrapped before your eyes! (I want to celebrate that holiday now...) Our other designer is apparently part sponge though, and wanted to soak up as much knowledge as possible from every source possible to learn and try to produce the best product we can. After a very non-intense, 5 seconds of this desgner saying "I think we should do this!", we all agreed, and set up a time with our friends!

Our friends are indeed big brained. Despite our best efforts, Kayla and I are getting known around the PNW robot scene. However, these folks have been building (amazing) robots together in more states than us, for longer than us, and are pretty well known internationally at this point. That they offered and made time to provide us some input - we are wicked thankful! (Thanks again!) We met early in the week - and to be honest, we were a little further behind with the CAD than we wanted to get this review. Mainly, we hadn't had the playtime with our prototype intake that we wanted, and we also didn't have the intake attached to the assembly in CAD. Everyone was happy to work around this, and we got some really nice thoughts and ideas out.

CAD for the intake panels for the intake we were prototyping. 
Sadly we didn't do the review on this giant, wonderful screen.

Be simple, be rigid, be lightweight, be simple again. Some of it I have preached, some of it was timely reminder, and some of it was new ways to solve a specific problem. To be fair, they shared the same concerns about our intake and how we really need to just mess around with a prototype more and make sure it does what we want it to. We also had some fun stories about weight distribution and chain stretching in some of their previous robots. Even with their key points in the review - be simple, be rigid, be lightweight, be simple again - everything is a tradeoff. Removing this degree of freedom would require us operate the robot slightly differently. Making this more rigid would increase its weight. Over the course of the week, our design students would take this feedback, try to balance these trade-offs, and make the best decisions we can with the information at hand.

Ok, my shorthand notes are bad - but somewhere in here, we re-learned once again the importance of taking macro and micro views of the robot assemblies, including where hardware and wires exist in the model. From last week, it takes a lot of effort and process to completely define, power, and constrain a rotating joint. While reviewing our early iteration, we encountered this lovely phenomenon where we rotate some parts right through their own mounting hardware. In the games industry, maybe that not a ship-stopping bug, and we can put out a patch later to fix it. With robots, we sadly don't have that option. (One day though...) Catching these problems early in CAD can prevent a lot of headache further down the line.

Now that design is out of the way, let's talk fun stuff! We have super snazzy practice bumpers! With these, we can finally set the robot on the ground and start dialing in some of the drive software, and check out some options for building autonomous paths! Our first lesson in software came early - field oriented, or driver oriented? Well, our plan was to organize this huge meeting with full catering, professional consultants, expert panelists, game day announcers and more - but then another mentor came over and said 'well it depends, what do you prefer?'. So we scrapped the entire idea and decided to just drive around and see what's what.

Pretty popular look for software these days,
checking out wheels with a T-square.

We also got a hardware store trip in, and gathered the remaining items to have a super simple Speaker mock-up complete! With this, lots of students can throw Notes around the shop and hopefully not hit anybody! (I suppose they didn't need this to throw Notes around, but I appreciate that they waited...)

This week we were far enough down the line with design that it was time to make sure all the sub-teams were on the same page of the same book. Our integration meeting brings together design, software, electrical (and sneakily manufacturing) to ensure that we have a documented (ehem...) blueprint for the robot and its functions. Ideally this meeting covers a wide variety of information for power, rotation, control schemes, sensors, everything that each specific subteam needs to ensure is on the robot and able to perform its task.

* How many actuators for each subsystem?

* Are we able to produce or purchase each part on the robot?

* Do we have any specifc mechanism assembly steps? (We have 2 specific assembly procedures on this year's robot. If we don't put them together correctly, they may not perform well due to excess friction or out-of-round-ness.)

* Are there any specific sensors that need to be included in the mechanism? (Including use of built-in or external encoders?)

* What are the ranges of motion and limits for each mechanism?

* Are there any mechanical hardstops for any ranges of motion?

* How does the driver or operator perform each robot action?

* What controller buttons does each action map to?

In truth, not all of this is explicitly communicated during this meeting, some of it comes from design reviews, or "hallway conversations". But it should be documented (ehem) so that each group can make forward progress in isolation.

More gratuitous images of software playing with robot.

I mentioned previously that we aren't the fastest with putting together prototypes, and one reason for this is parts availability. Our shop doesn't look like a mini version of AndyMark's warehouse. (Which is sad because I hear that place is cool.) We had finished assembling and getting power to our v2 prototype, as a mismash of bits from last years spare intake and some other random stuff we happened to find. After it was all said and done, this v2 prototype was a complete failure! And because of that, it was a success! 

Prototypes are fun, because their entire purpose is learning. Just like Edison, we discovered another method to not launch foam torroids at a semi-arbitrary velocity. So, first off was the parts bin assembly. Want 3" wheels and 1" wheels? We tried it. Even with the motor speeds offset to account for the diameter difference, it flopped a Note out with all the acceleration of a boulder getting blown on by a mouse.

Because we stole the wheels and axles from our 2023 spare intake, the span between our sideplates was 13", squishing the Note as it intaked and exhausted. More learnings! Somewhere in the depths of our storage bins, we found some 2" squishy wheels, and 2" omni wheels. <shrug> Can't hurt anything to try. Using the highly successful method of "that last prototype was bad lets change all the variables", we found new shafts, grabbed the 2" wheels, and rebuilt the thing with a 14.25" span. This time we flung the Note with some pace. Not nearly enough pace, but we were at least headed in the right direction. If we had more supplies we would have continued trying, but at this point we had new geometry in CAD we wanted to try, and more/different wheels on order. That sounds like a job for week 4 Bearcats.

Making the best with what resources we had in the shop from
last year and some random bits from our summer project.

QotW:

Student 1: "What do you think of monkeys and talking birds?"

Mentor 1: "I think a room full of monkeys with onshape would get the intake done faster than this..."