Team 254 - 2014 Build Blog + Tech Binder
 

Hi everyone,

Although it may be a bit late, we would like to release this year's Build Blog and Technical Binder. Both these resources are now publicly available on our website.

We tried to keep the Technical Binder simple and use it mostly as a visual aid when explaining the robot to judges, so if you have any questions or want more specifications, feel free to ask!

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Wow. This is awesome!
Thanks for releasing these!

Re: Team 254 - 2014 Build Blog + Tech Binder
 

New CAD computer one day and the 254 Build Blog + Tech Binder the next? Christmas in July really does exist.

On a more serious note, I always love reading these and am forever thankful to Team 254 for documenting and releasing such an amazing learning resource each year.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

One of my favorite parts of the summer. There goes an evening! (not complaining) :D

Re: Team 254 - 2014 Build Blog + Tech Binder
 

I love the technical binder. That's the prettiest FRC publication I have ever seen and one the most useful. Thank you

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Can I ask a logistical question here -- reading the blog (which is amazing, by the way), how were you able to accomplish just the amount of time dedication to the team during the build season? I counted a total of 3 Rest Days.

How can the mentors juggle it with work and family, and avoid burnout? How do the students handle it with homework, midterms, etc?
Our team has had to basically shut down for a week in late January because of midterm exams. Putting in 8 hours a day every single day just isn't practical.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

We were able to do what we did without a large amount of burnout mostly because we had a large enough team that the load would not be placed on just a few individuals.

During the build season we had four rest days (these are all in the blog), all Mondays, excluding the first Monday, when we just starting the season, and the last one, which was during a week off from school so the students who wanted to were able to come. After we bagged up the robot, we all took a couple of days off. Also after bag and tag, our blog posts became less frequent (as did attendance), and so days of rest were not officially noted on the blog, though Mondays were still days of rest.

Additionally, lab safety policies put a cap on occupants, so the team limited signups for the lab to 3 days per week for students, though this was only enforced on weekdays when more students wanted to come, so I would often be there 4-5 days per week during build season. This limit allowed me to choose which days I would not attend, and so I would check my schedule to align that for when I have a test (as a sidenote, Bellarmine did not have official midterms, just big tests spread throughout the semester, so we dodged that bullet). I often was at the lab between 5 and 10 most days, and since school got out at about 3, I had a daily 2 hour block for homework. Any additional homework was done in the mornings before school.

The key to balancing robotics, school, and the rest of one's life (so as to avoid burnout) from my experience has been making a schedule and sticking to it. When I say "lab between 5 and 10" I meant it, the latest I ever left was 10:36. Schedules are also easiest to keep when they are regular, so I got into a very nice groove of school, homework, lab, sleep, repeat throughout the build season.

Some numbers to go along with this (Lab times courtesy of our sign-in system, which is in the cloud):

• Total hours: 225.8 (6th most for 254)
• Average times: 5.0 hours
• Standard Deviation: 2.0 hours
• Median/Mode times: 4.3 hours
• Longest/Shortest times: 11.8, 2.4

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Not only do we have a really large team (90 students, at least 30 in the lab every night) but we also have lots of mentors to distribute the workload. I have no idea how the mentors balance robotics with work/family, they are truly amazing.

Also, builds are usually not 8 hours long. Weekday builds start at 5:30 (mentors get off work), we spend an hour eating dinner together, and then most students leave around 10 or 11pm. Weekend builds go from 1pm to about the same time but sometimes end as late as 3am. However, students will sometimes come in shifts for weekend builds.

Our school does not give that many midterms, especially to underclassmen, so we don't take time off for that.

Despite all that, it does take a tremendous amount of time to be a member of this team, but in the end I think it all pays off!

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Until the end of build I don't think we had a single true break day. We had 3 Mondays that were "breaks" where the majority of the students and some mentors didn't come, but we still had some mentors and students there for all of them.

We took a few true break days post ship and worked reduced numbers of hours relative to during build, but still quite a lot.

This season was infinitely better than last year. 2013 was a nightmare. It took so much work to integrate all our subsystems and to complete the hanger. We also had fewer mentors, which took a toll on us. There was a 4 day stretch during the last full week of build where I was at the lab from 4 PM until no earlier than 4 AM, with one night until around 6:30 in the morning and another where we didn't go home. This year we didn't have a single night that was as bad as any of those.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

I'd love to get a link at your Trello board (boards?) from this season. Would you guys be willing to share a link?

Re: Team 254 - 2014 Build Blog + Tech Binder
 

We ended up ditching Trello partway through build season (due to difficulty of keeping it in sync) and went with a more analog solution.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Thanks. We had decent success using Trello for our drawing creation, review, release, and mfg workflow. We had about the same experience as you did trying to use it for our overall activities.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

This is an excellent resource, thanks for sharing! Now, if only I could get the rest of my team to read this...

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Good idea. :rolleyes:

We gave Trello a shot this past year and it was much easier to implement during the fall as there was more time to keep it up to date and time to check it. It almost needs its own staff of a few students to keep it up to date and clear/archive/move around old cards/boards. We found it is a great tool for the offseason when meetings are infrequent and commitment levels are lower.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

I'm curious, in the Tech Binder, I'm looking at the Excel Spreadsheets...

For Seconds to Completion and Probability of Completion, are those what you think the "Average" team will do or what you think your team can do?

Re: Team 254 - 2014 Build Blog + Tech Binder
 

They are what we guessed/expected would be the average amount of time and probability for the average team in Qualification Matches.

For example, certain teams, especially in eliminations, were able to have a successful catch probability much larger than 10%, but it rarely happened in Qualifications.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

To add to what Andrew said, there was significant error in those estimates stemming from the fact that on the day of kickoff we neglected to consider that there would always be up to two opponent robots with nothing to do but play defense.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Gotcha, thanks

Re: Team 254 - 2014 Build Blog + Tech Binder
 

The spreadsheet model evolved a lot over time. The version that made the tech binder is close to the "final" version we had (from near the end of build season), before we started to see the game played for real.

It was interesting to watch the model evolve over time. We initially severely underestimated pedestal lighting/ball return time, as well as the ability of the average team to acquire assists fairly quickly by inbounding. As a result, on day one, one robot hurdling, self-catching, and scoring was looking pretty tempting.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Looking over your gearbox data/render in both the blog and the technical binder I was wondering why your team chose to orient the CIM motors the way you did. I'm relatively new to gearbox design and I rather like the triangle method that west coast products and AndyMark use. I just wondering what your team's reason was for doing it the way you did.

Is it possible that I could get a look at the .STEP file for the gearbox?

Re: Team 254 - 2014 Build Blog + Tech Binder
 

The height required to do so would interfere with their mechanisms for ball loading.

It's a cool variant that can be used to save height, and space on one side of the robot.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

The biggest issue was that we couldn't get the ratios we wanted with the triangular configuration.
Our cluster gear isn't big enough to get 3 CIMs and a shifting piston around it.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Ah. Sorry for the misinformation then.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

What you said was true, also. The ball did hit the cRio and was close to the CIMs when it was fully inside the robot. There is no way it would have fit the other way, ignoring the cluster gear size.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

FIRST (:p) of all, thanks for releasing these! The tech binder is just beautifully made! I had some questions though.
1. It's mentioned your drive train was designed for sudden bursts of acceleration, but you're geared for 20 fps+. Why was such a high speed chosen over a lower speed that would have accelerated faster?

2. You had quite a bit of motors and pistons on the robot, how was your battery life?

3.I recall you experimented with alternate material for bumpers this year, how did they hold up?

4. No recipes in the build blog? Has the lack of free corndogs doomed us all?

Re: Team 254 - 2014 Build Blog + Tech Binder
 

1. In order to have both high acceleration and top speed, we chose to have 6 CIMs. We didn't want to sacrifice a high top speed, especially on a field as open as Aerial Assist. Also, one of our initial strategies in Quals was to go for 1-assists with solo-catching, and thus a high top speed would be very advantageous.

2. The 6 CIMs on the drivetrain were the biggest power draw. The only problems we had were when we tried to push other robots while in low gear, sometimes the breaker would trip. We would obviously replace batteries between every match, and we also purchased some fresh batteries before Champs because the 12 we'd been using for regionals were starting to die.

3. We didn't too much experimentation ourselves with bumper material, but we looked at what 971 and other teams did and tried to improve upon it. We used Cordura bumpers for the first 2 regionals and then switched to Sailcloth bumpers after that. The new bumpers had a coefficient of friction as low as .2 (compared to Cordura's .4 I think). They helped with driving around defense immensely and the material held up pretty well. The biggest problem with the new bumpers was that we ironed on the numbers instead of sewing, and thus sometimes the numbers would bubble up or rub off.

4. I don't recall how many times baked things for the lab, he could answer the questions better than myself. However, one night we did make s'mores using a heat gun. It was awesome!

Re: Team 254 - 2014 Build Blog + Tech Binder
 

I essentially baked the same things as 2013, in the same order, and I was too lazy to copy the same recipe blog posts over from last year's blog. :)

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Sorry for asking this a while after this was released. I've noticed you guys have mentioned you needed to be creative to get tubing on your intakes. How was this actually done on the finished robot?

Re: Team 254 - 2014 Build Blog + Tech Binder
 

I'm not 100% positive, but I'm pretty sure it involved using a bit of lube, compressed air (to inflate the tubing like a balloon), and A LOT of strength to stretch the surgical tubing over the 1" aluminum tube.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

We didn't end up needing any lube, just two people and compressed air, it worked pretty well. To expand, these rollers were one of my favorite parts of the robot this year; simple, effective and cheap.

Re: Team 254 - 2014 Build Blog + Tech Binder
 

So is there any chance you guys will release the cad files for this years robot? It would be amazing to be able to check it out on CAD. :]

Re: Team 254 - 2014 Build Blog + Tech Binder
 

Colin and Andrew already answered, but another good trick for getting tubing onto a shaft is to coat the inside with plain old rubbing alcohol. It makes it slide better and will evaporate when you're done and everything is on there.