First Robotics Books

[cjackson]

I recently found the First Robotics: Behind the Design books on Amazon and our team was wondering if they were more of a coffee table book of stories from the teams, or if they are educational and would be a great help/investment for a Rookie Team.

[kgzak]

Here is a little part of the book: http://books.google.com/books?id=LZT...sign& f=false I know our team has a copy of the book. I first looked over it (didn't have time to really read it) 2 years ago. I found it pretty interesting.

[Chris is me]

They're worth buying. Check out a random team's article using Google Book Search to get a quick preview; it's quite impressive.

[JohnBoucher]

There are two editions. One from the 2006 and one from the 2007 season. They are an amazing resource on the thought process that goes into the design of the robots.

Teams that won technical awards that season submitted a presentation and 30 were selected for each year.

They are a great read and will give you a lot of insight as to how teams work.

[Madison]

They're a little bit of both, really. The text of the books is, in many cases (and perhaps only in my opinion), sparse on useful technical details. If you know what you're looking at, though, and what you're looking for, the pictures and drawings are a helpful resource.

[EricH]

I'd get both. They are coffee-table books, but they give a lot of insight into the processes behind some of the top teams in FIRST. 1114, 111, 357, 330, 190, and 33 are just some of the teams that I remember being in one or both. 357 happens to have a patent on an item they developed in FIRST; some of 33's software wound up in at least one Chrysler model some years ago, IIRC.

[Ether]

I was wondering if there's someone from Team 75 who could explain the attached excerpt from page 78 of the 2008 edition. It doesn't sound right.

[EricH]

The Big CIMs were before you were involved, I think--I remember them in '06 and maybe '07. Many teams noticed that they didn't have the same or better performance as the CIMs that we use these days, which we also had then. They were also about the third-heaviest item in the KOP, weighing in right behind the batteries and the compressor. Hence, a lot of teams didn't use them.

The teams that did tended to use them outside of the drivetrain.

[Ether]

Originally Posted by EricH

The Big CIMs were before you were involved, I think--I remember them in '06 and maybe '07. Many teams noticed that they didn't have the same or better performance as the CIMs that we use these days, which we also had then. They were also about the third-heaviest item in the KOP, weighing in right behind the batteries and the compressor. Hence, a lot of teams didn't use them.

The teams that did tended to use them outside of the drivetrain.

OK, I can understand not using the large CIMs because of their larger size and weight, but that was not the reason given.

According to the motor curves I have, the large CIMs seem to be more efficient (power out divided by power in) than the small CIMs. Perhaps I have the wrong curves? Or perhaps it wasn't a question of efficiency but rather the higher power output of the small CIMs ?

Is there someone from Team 75 that remembers this analysis and could fill in some details?

[EricH]

IIRC, it was the smaller CIMs had a higher power output. Big CIMS appeared in places like 330's shooter and in various lifts; not many were in drivtrains.

[Chris is me]

Originally Posted by Ether

OK, I can understand not using the large CIMs because of their larger size and weight, but that was not the reason given.

According to the motor curves I have, the large CIMs seem to be more efficient (power out divided by power in) than the small CIMs. Perhaps I have the wrong curves? Or perhaps it wasn't a question of efficiency but rather the higher power output of the small CIMs ?

Is there someone from Team 75 that remembers this analysis and could fill in some details?

Not from 75, but I think they meant that a big/small CIM combo geared for the same free speed as a 2x small CIM combo would draw more current under load.

[Ether]

Originally Posted by Chris is me

Not from 75, but I think they meant that a big/small CIM combo geared for the same free speed as a 2x small CIM combo would draw more current under load.

Thanks Chris. I'm trying to parse what you wrote. Are you saying that the comparison was between

a) 2 small CIMs driving a gearbox

and

b) one small CIM plus one large CIM driving one gearbox (so that the small and large CIM are being driven at the same speed ?

I wouldn't have guessed that from what was written.

If what you say is true, sure that's not optimum. The large CIM's NLS is half that of the small CIM. There's no way to operate such a design efficiently.

[Chris is me]

I believe a larger pinion was put on the large CIM to compensate for this.

[Ether]

Originally Posted by Chris is me

I believe a larger pinion was put on the large CIM to compensate for this.

If the large and small CIMs were geared so that each one was running at the same percent of its own no-load speed, then the large+small combination should be more power-efficient than the small+small combination, according to the motor curves I have for the large and small CIMs.

If there's a piece of the puzzle that's missing perhaps someone from Team 75 who was involved in this analysis would clarify.

[IndySam]

AndyMark produced a special version of their super-shifters to allow the use of one big cim and one small.