Is there a dominant design style?

[Kevin Leonard]

Originally Posted by Knufire

"Because they do it" shouldn't be your rationale. Yes, all the top teams doing something is generally a indicator that it's a smart decision. However, blindly following them without figuring out the rationale behind their decisions is a bad idea; there might be variables at play that made WCD the right choice for them but not for you.

Note how Corsetto said that 1678 is going to keep learning from the teams they're inspired by. Copying 254 or 973 probably had some sort of analysis of their resources and what direction was best for them.

There are successful teams that do WCD, there are successful teams that do omnidirectional drives. There are successful tube and gusset teams, there are successful sheet metal teams. Which one is right is completely dependent on the resources available to your team.

I really like this post in that it illustrates something that is hard to understand.

There are successful teams who use WCD, Sheet metal, swerve, kitbots, and every other style in-between.

The success comes not from using a particular style of drivetrain, but from building the right kind for your team. That goes for most mechanisms too.

5254 and 20 are both probably going to use shifting 6 Wheel WCD's in 2016. 5254 will use Versaframe and gusset one together, 20 will use stock tubing and weld it together.
5254 will likely use a lot of COTS parts and gearboxes for everything and try to build something incredibly simple and then iterate on it. 20 will likely have a detailed CAD drawing of a robot we hope will be able to compete at the highest levels, then work with it until it works like expected.

Both have the potential to be successful in 2016, despite varied styles of build and materials available.

Use what's right for your team. Do a detailed engineering analysis of what makes sense for you. Don't be dissuaded by people who say you can't win without this resource or that resources- they're wrong.

[MrForbes]

Originally Posted by Kevin Leonard

The success comes not from using a particular style of drivetrain, but from building the right kind for your team. That goes for most mechanisms too.

Since the modern kit chassis/drivetrain is pretty good, if you use it you can spend more of your effort on figuring out the game and building great mechanisms. Great teams can win with whatever drivetrain they pick...it's really not that important.

[GreyingJay]

Originally Posted by Michael Corsetto

Totally agree! Well put.

"Blindly following" and "not figuring out rationale" are pretty poor ways to approach the problem.

Also known as the pot roast rule.

[Taylor]

In my experience, I have seen the highest correlation between robot performance and quality bumper design*.


*obviously not valid in 2015 or before 2008

[zinthorne]

We used to use the vexpro ball shifters until last year. We stopped using them, because we broke several in 2014, and ultimately went through 4-5 total in 2014. We not use the wc products ss gearboxes. We will go with an 8 wheel WCD this season, barring some very odd game. We are will likely also to chain in tube. We went through an extensive drivetrain research last season and decided WCD is the drive of the future for us.

We use vexpro versaplanetarys for everything else.

[Andrew Schreiber]

Originally Posted by Taylor

In my experience, I have seen the highest correlation between robot performance and quality bumper design*.


*obviously not valid in 2015 or before 2008

I always use this rule for third bots. But there're plenty of robots that have been decent but had TERRIBLE bumpers. Ok, actually this is just an excuse to pull out one of my favorite pictures:

https://scontent.xx.fbcdn.net/hphoto...10&oe=56DB5819

[Mitchell1714]

Originally Posted by Andrew Schreiber

I always use this rule for third bots. But there're plenty of robots that have been decent but had TERRIBLE bumpers. Ok, actually this is just an excuse to pull out one of my favorite pictures:

https://scontent.xx.fbcdn.net/hphoto...10&oe=56DB5819

This also has to be one of my favorites. Especially since it won a regional.

http://archive.firstinspires.org/sit...?itok=dMTXO-FG

[Ty Tremblay]

Originally Posted by Knufire

"Because they do it" shouldn't be your rationale. Yes, all the top teams doing something is generally a indicator that it's a smart decision. However, blindly following them without figuring out the rationale behind their decisions is a bad idea; there might be variables at play that made WCD the right choice for them but not for you.

Note how Corsetto said that 1678 is going to keep learning from the teams they're inspired by. Copying 254 or 973 probably had some sort of analysis of their resources and what direction was best for them.

There are successful teams that do WCD, there are successful teams that do omnidirectional drives. There are successful tube and gusset teams, there are successful sheet metal teams. Which one is right is completely dependent on the resources available to your team.

This. So much this. I was just discussing with my friends how it seemed that the most popular things teams are taking from the latest Behind The Lines episode were drill drives and tape, and not the processes that these great teams used.

Drill drives and tape will not make a good team, and probably not even a good robot. Understanding that 118 has a well defined and thought out prototyping process, and working to develop one for your own team, will go miles further toward improving your team and robot.

That's not to say you shouldn't use drill drives and fancy tape. Go right ahead. But don't miss the forest through the trees.

[Pat Fairbank]

Originally Posted by Knufire

"Because they do it" shouldn't be your rationale. Yes, all the top teams doing something is generally a indicator that it's a smart decision. However, blindly following them without figuring out the rationale behind their decisions is a bad idea; there might be variables at play that made WCD the right choice for them but not for you.

Yep. I call this phenomenon "Cargo Cult Robotics".

[mrnoble]

Originally Posted by Pat Fairbank

Yep. I call this phenomenon "Cargo Cult Robotics".

Okay, so what am I missing? A lot of folks here are saying basically the same thing: don't be slavish. Fine. Bu,t we built our first WCD as an off season project a year ago and loved it; we are on our fourth WCD build right now. Is it wrong that we took inspiration from teams we admire (including 254)? Is it bad that we are planning on using this construction style for all future projects, barring some radical reinventing of the FRC game?

A far as vexpro gussets are concerned, that one is a no brainier. I actually contacted a company in Russia four years ago in hopes of buying exactly the product that Vex now produces. We have no welding capability, so riveting works for us.

[Ty Tremblay]

Originally Posted by mrnoble

Okay, so what am I missing? A lot of folks here are saying basically the same thing: don't be slavish. Fine. Bu,t we built our first WCD as an off season project a year ago and loved it; we are on our fourth WCD build right now. Is it wrong that we took inspiration from teams we admire (including 254)? Is it bad that we are planning on using this construction style for all future projects, barring some radical reinventing of the FRC game?

A far as vexpro gussets are concerned, that one is a no brainier. I actually contacted a company in Russia four years ago in hopes of buying exactly the product that Vex now produces. We have no welding capability, so riveting works for us.

The important part is that you tried it as an offseason project instead of blindly doing it because a team you admire does it. You saw that a team did something a certain way, then tested it to see if it worked for your team. You figured out the "why" and the "how" behind the "what".

[Knufire]

Originally Posted by mrnoble

Okay, so what am I missing? A lot of folks here are saying basically the same thing: don't be slavish. Fine. Bu,t we built our first WCD as an off season project a year ago and loved it; we are on our fourth WCD build right now. Is it wrong that we took inspiration from teams we admire (including 254)? Is it bad that we are planning on using this construction style for all future projects, barring some radical reinventing of the FRC game?

A far as vexpro gussets are concerned, that one is a no brainier. I actually contacted a company in Russia four years ago in hopes of buying exactly the product that Vex now produces. We have no welding capability, so riveting works for us.

Not at all!

1. Off-season project: This indicates that you acknowledged that there were potentially variables or aspects of a WCD that you didn't fully understand, and that these caused an inheriant risk if you tried this out during build season. Building it during the offseason meant you wanted the opportunity to find out what these variables were, so that you could isolate and control them when you first built a WCD for competition use.

2. Iteration: You say that you're on your 4th WCD build. I'll go out on a limb and assume that it's not exactly the same as your first one. I'm sure you have tried to make improvements upon each design, and that these improvements are tailored towards your experiences with the drive and resources available to you. I'm sure that some of the details of your implementation are not exactly identical to that of 254.

Due to these, you've definitely gone through some sort of learning process and gained some lessons during your work on your WCD.

I'll explain my original post with an example of what I would recommend to avoid; I talked to a team during this season that wanted to improve their intake. Their solution was to plug in a 2nd monitor, pull up the best picture they could find of 1114s intake, and copy it as perfectly as they could given the information they had. While I'm a fan of doing anything you can within the rules to be as competitive as possible, I think that you lose out on a lot if you attack a problem with this approach. What I would recommend doing instead is building a quick prototype of the intake, figuring out all the critical aspects of it, and implementing it in your own team's construction style. While it might take a bit more time, you probably end up with a system that performs just as well, but is easier for you to manufacture and easier to integrate with your robot than a carbon copy. In addition, you learned a lot more than if you just copied everything you can see, including some tips and tricks that you could use on a future robot as well. Win-win.

Sure, you stole a concept from 254. But you took the time to implement it yourself and tailor some of the details to your liking, which IMO is where the real learning happens. You don't reinvent the wheel in the real world either; innovation is what drives engineering.

[bEdhEd]

Originally Posted by lethc

While I agree with your point, I don't think 1678's WCD is what made them world champion caliber.

I may not have provided enough context. Of course WCD is not what made them champs, there's a lot more that goes into it. The situation with my team was at the beginning of the season, we had experimented with a slide H drive and found that was not a good for going over the platform since our middle omni wheel made the robot bottom out and lose contact of the floor with some of the outer wheels. We then moved on to mecanum since we still wanted to try the strafing autonomous.

Looking back on the season, we realized how much time and material we wasted manufacturing plates for the H drive that was never used and the near uselessness of our mecanum strafing since the auto never played out. We could have just kept with what we already have made the past three seasons in a row.

WCD is a good choice for us because we either will be able to make one quickly or have one one pre built for prototyping early in the season. Since this is a drive system we can easily produce, it's a good choice to stick to for prototyping at the very least.

I use the example of 1678 since we had anticipated early on that the better teams might use strafing to make landfilling or chute lining easier. The whole point is that regardless of the style and layout of the game, some form of WCD is likely not a bad choice for us and other teams who also regularly use it, as long as drivers are well practiced.

[thedude019]

Originally Posted by techtiger1

6 WD is the most common design style, I challenge the OP to find a game where swerve drive was necessary/needed.

it seemed useful in lunacy...

[jwfoss]

Originally Posted by thedude019

it seemed useful in lunacy...

While it seemed useful, 2/3 (971 and 67) of the World Champs had 6WD.
And just for reference, check out this article posted on FRCDesigns.

Dominant styles of design also vary by region.
Ultimately it is most important for teams to choose a strategy and design that they can build within their resources.