Monday, January 17, 2022

2022 Day 9: Bootcamp Build Day & a successful climber prototype

 Bootcamp Build Day

We started the day with our 1st Bootcamp Build Day of the year we had students and teachers representing 5 young Houston area teams on site for a few hours to answer their questions, give design advice, and help with the FRC control system. Members of Pearadox FRC5414 were here to help as part of our partnership in the Houston FRC Development Program this year. Our next session is in two weeks and we will be helping teams finish up their drive bases, electronics, and making progress on their robots. 

Climber Test

We were able to rebuild the climber prototype after last night's crash and improve it in the process. Below is a video of it successfully pulling from one bar to the other. With a little help to limit the swinging this time. In the next version, we will add springs to extend the upper arm and a pneumatic cylinder to extend the lower arm.


The theory behind the climb

Here is the basic idea of how we currently plan to implement the climb.



- Spectrum






Sunday, January 16, 2022

2022 Day 7 & 8: Intake Testing and a New Climber Concept

Intake Testing

We started on a more complete intake test rig with bumpers and more adjustability.


We are using silicone bands in this video, soft silicone has worked well in our past intakes (2019) and it appears to grip the balls well this year.

Simple Tests

A lot of our "prototypes" don't need to be complicated to prove concepts. In this quick clip we used part of a prototype from 2020 to see how the balls would behave if we used a timing belt as part of  a ball tower.



Climber Concepts

 We began working on a new climber concept that uses a double-jointed arm that extends with springs and climbs with a winch. The geometry of this climb appears to work better than some of the others we were working on.


We spent time today mocking it up with laser-cut parts and 3D printed connectors. The 2 extra CIMs are just for ballast to simulate the center of mass of the actual robot.

We were able to complete the construction of our practice hangar and run the prototype on it. One of the first attempts with the prototype went one of the more predictable ways.


We will rebuild it this weekend with lessons learned (more perimeters in the prints, more gussets, and bolts/rivets into the tubing) and hopefully future attempts will be more successful. Failures like these are to be expected while prototyping, this is why we often use scrap material or cheap and quick-to-make parts like the 3D printed tube connectors and shaft collars. Failing quickly is one of the best ways to get a robust system in your final robot.'


- Spectrum

Friday, January 14, 2022

2022 Day 6: Climber Model

 We made a 1/5th scale model of one of our climber ideas. This one has several issues, and some of them are caused by it being scaled-down, and some of them are likely inherent in the design.



We made several interactions, printed, and laser cut some parts, so the joints acted more like we wanted; we also added nuts to simulate the robot's center of gravity. These helped but didn't fully solve the problems.

More videos and photos can be found in our photo gallery: 

https://photos.spectrum3847.org/2022-FRC-1/2022-Build-Season-1/Week-1/


From playing with this model and doing more CAD sketches, we will likely add another degree of freedom to the system, most likely a motor (possibly pneumatic) to extend and retract the hook on the arm. This should allow the climb to behave correctly across various center of gravity positions and enable us to quickly climb to the mid-bar without fully completing the first curl of the whole climb sequence. We also still discussing if we will use chain/sprockets or a Dyneema cord winch to power the arm joint. 

Here is a sketch of the new configuration; this has a 6 in extension and appears to work with a center of mass 6.5" to 15" and roughly centered in the robot. Not shown, but if we needed this climb should be able to curl onto the low bar for 4 pts. 


- Spectrum



Wednesday, January 12, 2022

2022 Day 5

Wednesdays are normally pretty slow. We got some more parts cut for our practice field elements, did some manual intake material testing (i.e. rubbed lots of types of rubber and wheels on the balls), and we had an awards meeting this evening to get our Chairman's Essay nearly finished.

We were able to inflate the balls to the proper 3.5 psi, before today all the gauges we had in the lab didn't read that low. We purchased a digital inflator from Amazon that very easily inflates the balls to 3.5 psi automatically and it works great. We were testing balls at various states of inflation since we didn't know what was right, in general, most of our balls were underinflated in any previous test to what degree we don't know (we didn't have a gauge that could read it remember). The balls are very firm when fully inflated to the spec 3.5 psi.

Link to the inflator - https://amzn.to/3Fn329g


The push will be to do more intake and climber prototyping over the next few days.

- Spectrum

Tuesday, January 11, 2022

2022 Day 4: Design Slides, Recap, and FIRST Choice

 Design Slides

We have decided to make a public version of our design slides this year during the season. We use the google slides document to keep track of large parts of our season. We create slides for our weekly design recaps and collect notes and ideas about the robot. We will update the public version a few times a week with slides from our internal notes (if we share the private one, you all can watch us type, and that's a tad weird).



Design Recap

Today was our first design recap. It was an overview of our intent for each mechanism, along with updates on testing and design progress. Here are a few of the sample slides from tonight.


FIRST Choice Recommendations Updated for Round 2

Our 2022 FIRST Choice and Voucher Guide has been updated with a sample priority list for Round 2.

Every team gets 710 more credits, and some really great items have been added that will probably help your team be sure to submit your priority list before Jan 20th. 

- Spectrum


2022 Day 3

 The first day of the season with a normal after-school meeting is mostly just a recap of the weekend and discussing various strategy ideas and the road map to each of our mechanisms.

We planned how we would group the various mechanisms on the robot.


As well as how each of those mechanisms mounts to, supports, interacts with, and avoids the other mechanisms on the robot.


We can start allocating some space in the robot as the mechanism designs become clearer.

Much of that will depend on the requirements of our climber; the other mechanism can largely be designed around things and still function well. Since the climber has strict dimensions to get from bar to bar, it will get some amount of priority to space.

We have also begun building our team version of the high hub and will begin the hangar this week.

- Spectrum



Sunday, January 9, 2022

2022 Day 2: Dabbling in Prototypes

Photo Gallery

Our 2022 photo gallery is up and will have updated photos and videos of our prototypes and progress this season.

https://photos.spectrum3847.org/2022-FRC-1/2022-Build-Season-1/


Intake Prototype

We were able to use a prototype mechanism we built in the fall to begin testing how the balls interact with various materials.

We used 2" compliant wheels, polycarbonate tubing, and velcro wrapped around the tubing. All of them were able to intake the balls pretty well but the compliant wheels seem to do the best job of grabbing the ball in our limited testing.


Launcher Prototype

In 2020 used one of our 2017 launchers to build a prototype for that game pieces. We kept that around and adjusted it today to make it fit the larger 2022 balls. We adjusted it to 7.5" between the wheel and the hood to allow about 2" of compression on the balls. We have it mounted to our "ProtoCube." We've used this 2x4 box for multiple prototypes and it works well since you can clamp or screw into it and weigh it down easily with sandbags.


Strategy

We've also continued our discussion on strategy and robot goals. At the end of the 1st weekend this is roughly where we are heading, our course could quickly change as we learn more about the game and the game pieces.



- Spectrum