Team 254 - 2014 Build Blog + Tech Binder

[Torrance]

Originally Posted by Michael Hill

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?

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.

[Pat Fairbank]

Originally Posted by Michael Hill

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?

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.

[Michael Hill]

Originally Posted by Torrance

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.

Gotcha, thanks

[Jared Russell]

Originally Posted by Michael Hill

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

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.

[JohnFogarty]

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?

[AdamHeard]

Originally Posted by JohnFogarty

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?

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.

[NickE]

Originally Posted by AdamHeard

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.

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.

[AdamHeard]

Originally Posted by NickE

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.

Ah. Sorry for the misinformation then.

[Travis Covington]

Originally Posted by AdamHeard

Ah. Sorry for the misinformation then.

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.

[thatprogrammer]

FIRST () 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?

[Torrance]

Originally Posted by thatprogrammer

FIRST () 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?

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!

[Pat Fairbank]

Originally Posted by thatprogrammer

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

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.

[thatprogrammer]

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?

[Torrance]

Originally Posted by thatprogrammer

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?

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.

[Colin]

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.