Philosophies on design reuse

[StevenB]

Prior to 2007, the rules only specified that fabrication had to be done during the build season:

Originally Posted by FRC 2006 Game Manual

... But absolutely no fabrication or assembly of any elements intended for the final robot is permitted prior to the Kick-off presentation. Any MECHANISMS assembled prior to the Kick-off presentation may be used for prototyping or educational purposes, but MAY NOT be used on the final ROBOT.

Thus, it used to be legal to take a CAD drawing of last year's robot and make another copy. As FIRST has struggled to define what it means to "build a robot", this restriction has gotten tighter. While I don't think teams are intentionally breaking the rule, older teams are more likely to have the old mindset where detailed design reuse was completely legal.

[Tom Line]

The newest set of rules (2012) are straightforward.

Robot elements designed or created before the Kickoff presentation, including software, are not permitted.

The example even goes so far as to mention programming, and that teams should not copy over large chunks of code from year to year.

So the rules are straight forward and the intent is clear. Follow them to the best of your ability, and make your Grandmother proud.

[BigJ]

Originally Posted by Tom Line

The newest set of rules (2012) are straightforward.

Robot elements designed or created before the Kickoff presentation, including software, are not permitted.

The example even goes so far as to mention programming, and that teams should not copy over large chunks of code from year to year.

So the rules are straight forward and the intent is clear. Follow them to the best of your ability, and make your Grandmother proud.

Except for the blue box mentioning...

Originally Posted by Blue Box

Example: A different team develops a similar solution during the fall, and plans to use the
developed software on their competition Robot. After completing the software, they post
it in a generally accessible public forum and make the code available to all teams.
Because they have made their software generally available (per the definition of COTS, it
is considered COTS software and they can use it on their Robot).

I would argue that CAD designs "made public" should also count as COTS.

Rewriting code that instead could be reused (outside of educational purposes) or designed for reuse in the first place is a "bad thing" and should not be encouraged (in my opinion).

[JesseK]

Originally Posted by BigJ

I would argue that CAD designs "made public" should also count as COTS.

Rewriting code that instead could be reused (outside of educational purposes) or designed for reuse in the first place is a "bad thing" and should not be encouraged (in my opinion).

To what extent? (further explanation)

To be fair to Cory (that post is from 2007), every time I've looked at 254's 'bots at champs (every year since '07) there's probably very little that goes through no re-design of some sort due to new considerations.

Needless to say, there are many varied opinions.

My team uses pre-season items as prototyping platforms. Often times we'll have the entire drive train CAD'ed on the day of kickoff, just because we understand our simple drive trains that well. Then we fab the production drive train -- it's often similar to the prototype but it's never been identical. Only one part last year wound up being identical to the same part on 2011's robot, but that was after a design derivation and not a duplication. Seems to be within the spirit, even if we didn't open-source our robot.

[Cory]

Originally Posted by JesseK

To what extent? (further explanation)

To be fair to Cory (that post is from 2007), every time I've looked at 254's 'bots at champs (every year since '07) there's probably very little that goes through no re-design of some sort due to new considerations.

Needless to say, there are many varied opinions.

My team uses pre-season items as prototyping platforms. Often times we'll have the entire drive train CAD'ed on the day of kickoff, just because we understand our simple drive trains that well. Then we fab the production drive train -- it's often similar to the prototype but it's never been identical. Only one part last year wound up being identical to the same part on 2011's robot, but that was after a design derivation and not a duplication. Seems to be within the spirit, even if we didn't open-source our robot.

I believe we actually changed the parts in question a bit in 2008.

In all seriousness, even if you had a part that did not change at all there are endless ways you could change the design so it's not being reused. You could change the CAM file that generates the G-code to run the machine. You could make trivial dimension changes. You could issue a new drawing revision for some minor callout. You could change radii used on pockets/edges. The list goes on and on.

It's really a silly rule because FIRST is unwilling and probably more importantly unable to outline what qualifies as changing the design enough for them to be OK with it. It's also silly because anything you would re-use exactly as it was from the year before/offseason/etc is most likely a completely trivial part that would gain you no competitive advantage by designing up front.

The rule quite obviously exists to prevent you from designing an entire system of your robot before kickoff and then implementing it immediately, but you really can't design a system that can be used wholesale with no changes, because you have no idea what it needs to do.

[Tristan Lall]

Originally Posted by Cory

In all seriousness, even if you had a part that did not change at all there are endless ways you could change the design so it's not being reused. You could change the CAM file that generates the G-code to run the machine. You could make trivial dimension changes. You could issue a new drawing revision for some minor callout. You could change radii used on pockets/edges. The list goes on and on.

It's really a silly rule because FIRST is unwilling and probably more importantly unable to outline what qualifies as changing the design enough for them to be OK with it. It's also silly because anything you would re-use exactly as it was from the year before/offseason/etc is most likely a completely trivial part that would gain you no competitive advantage by designing up front.

I'm entirely in agreement with Cory on this point.

Absent guidance from FIRST, there is no standard for defining a change. If you paint the part differently, is that a design change? Different colour? Different composition? Different number of coats? Different method of application leading to different surface finish? Which functional characteristics are considered and which are neglected? To what degree must a design change be intentional, and/or consequential? What if you intend to make a change (as evidenced by your latest drawings), and then don't make the change—so that the part is now identical to a pre-season revision?

If you go down this road, there is no bright line, and thus there will inherently be inconsistency in interpretation. If FIRST accepts the inconsistency and its consequences, they ought to clearly say so. But if that inconsistency is incompatible with their stated motivations (I believe that it is), then they shouldn't make rules in this fashion. (Inconsistency in the rules adds the potential for conflict, so unless it is counteracted by a significant benefit, it should be avoided.)

Originally Posted by Cory

The rule quite obviously exists to prevent you from designing an entire system of your robot before kickoff and then implementing it immediately, but you really can't design a system that can be used wholesale with no changes, because you have no idea what it needs to do.

As I see it, FIRST should reconsider its intent: allow teams to design (and prototype) whatever they want before the build season, even if the design is destined for the final robot. That way there are no issues regarding what individual custom components remained the same through the pre-season and in-season design processes, despite being part of assemblies that were reconfigured during the season.

What's the worst that could happen? Teams could design robots and mechanisms in the hopes of having a suitable game? They could do engineering stuff year-round? Fine with me, and obviously fine with a lot of the more dedicated and more successful teams. Presumably fine with FIRST, too, since they haven't really done anything effective to curb it.


Additionally, the previous years' rules were hopeless from an enforcement standpoint because (in the general case) it is not practical for an official to evaluate all of the possible elements that could have been changed on moderately complex systems. Indeed, in nearly every case, the officials have no access to the previous designs (whether in schematic or constructed form) at all. The proposal I outlined above doesn't remedy this entirely, but simplifies the task considerably, because it then comes down to a simple question that can be much more clearly understood and answered by the team: "did you fabricate or modify any robot parts before the build season began?" (Granted, that is dependent on a good definition of fabrication/modification, but that's already covered for the most part in the rules.) Instead of the inspector having to evaluate the robot based on the dates of design changes, they evaluate it based on dates of modification. Modification is much more of a momentous event than design revision, and since it is more likely that any given team member will be aware of it, it's harder for them to forget or lie about at inspection. (And perhaps more importantly, if the team member does forget/lie, they're more likely to be called out on it by a fellow team member later on—so violators lose the shield of plausible deniability among the people whose approval they value most.)

Besides, my position is that (in a typical FRC game, rather than universally) an inspector should be giving the teams the benefit of any plausible interpretation within the rules. The teams are not the source of unclear rules, and they should not be penalized for successfully following a reasonable interpretation of those rules. (As a result, inter-event inconsistency sometimes ensues, but it is typically balanced by the fact that the teams are able to play, unburdened by surprise modifications, having complied with the apparent letter of the rules.)

[dtengineering]

We learn things as we go along in FRC. What we learn enables us to design better machines faster. It sounds like you learned a lot in the off-season. Never be afraid to embrace what you have learned, and use that knowledge on your machine.

I guess my suggestion, however, would be that the off-season and previous season knowledge should be stored in a human, or group of humans, rather than in a data file. After all, FIRST isn't really about the robot.

So in the event that the game that is announced on Saturday is perfectly suited for your off-season design, then just sit down at your computer, start with a blank CAD file, and re-create your design from scratch.

It might be identical to the off-season design, but you will have done the work during build season... you'll simply have done it faster, with more confidence and less troubleshooting because of experience you gained in the off season. By demonstrating your knowledge of a good design you'll not only be within the letter of the rule, but also the spirit of the rule.

Most likely, however, you'll find yourself making a few tweaks here and there to improve the off-season design or customize it for the game... I mean, what are the odds you'd build something so perfectly that it couldn't be improved upon a little bit?

Jason

[Wildcats1378]

I've never quite understood how FRC enforces this rule in the first place. Programming, for example: how does FRC know when you've copied code from last year?

Has anyone actually been disqualified for this? It seems more like a moral guideline then an actual rule.

[Tom Line]

Originally Posted by Wildcats1378

I've never quite understood how FRC enforces this rule in the first place. Programming, for example: how does FRC know when you've copied code from last year?

Has anyone actually been disqualified for this? It seems more like a moral guideline then an actual rule.

FRC can't enforce the rule. Of course, that begs the question "Why should they need to?"

If teams are really trying to stick by the rules as closely as possible, they already realize that reuse of entire designs or entire chunks of code is a no-no. Unless they post them on-line and make them available to everyone. I believe that's the end goal: to have teams sharing information freely (after the season and before the season) in order to bring everyone along.

If teams didn't share freely, you wouldn't see products like AndyMark's super shifter (designed in 2004 for team use), their AM planetary, and other products / designs. See the trapezoidal motion profile thread for a great example of teams who have a competitive advantage helping to bring others up to speed.

Of course, this all assume that teams get the idea of Gracious Professionalism. I'm going to continue to assume that. Most of the big-name teams constantly prove it (kit-bot on steriods, etc).

[IKE]

Originally Posted by Wildcats1378

I've never quite understood how FRC enforces this rule in the first place. Programming, for example: how does FRC know when you've copied code from last year?

Has anyone actually been disqualified for this? It seems more like a moral guideline then an actual rule.

The only time I have seen a clear ability to enforce the rule was when a custom piece had an inspection sticker from a previous year on it. I also saw a team bring last years robot to a competition (I think it was 2011, and they brought a 2010 bot). I believe they packed up and left (if memory serves me right).

[philso]

If a team is using the AndyMark C-channels, and they happen to determine that they should use the same motors, gearboxes and gear ratios and the same size wheels, as they had used in a previous year, they will end up with the "same design" for their drive base. It will also likely be pretty much the same as the drive base used by a number of other teams who arrived at the same solution. I don't feel this is bad as long as the teams went through the engineering exercise that happened to lead them to a solution they had used before since this is an engineering competition and one of it's goals is to teach the team members how do work through the engineering exercise. As someone had posted in an earlier reply "FIRST isn't really about the robot".

[Wayne TenBrink]

I would go one step further and argue that some amount of unregulated (predesigned and/or prefabricated) components/mechanisms should be allowed. Perhaps 10 or 20 lb (analagous to the withholding allowance) and only on the condition that you share the design and declare the items on the BOM.

Teams would still need to build a new robot every year, but at least they would benefit from the same advantages you get with buying a COTS mechanism. With all the FRC-specific COTS items on the market today, why invest time and money into building something that you can only use once, when you can buy a comparable unit and re-use it? Examples include gearboxes, swerve mechanisms, and now even entire drive modules.

In many cases, using a pre-designed or pre-fabricated mechanism would be more of a detriment than a benefit, because it would involve compromising function for convenience.

The current rules made more sense when every team had to make every mechanism because nobody could buy them. That isn't so true any more, and the FRC-COTS market is likely to grow. This might reduce the artificial exercise of lawyering our way around rules that are not and cannot be uniformly enforced in the first place.

[AdamHeard]

Raul posted a similar idea years ago, and I really like it.

Allowing 20 lbs of custom items to be reused year to year won't make good teams any better, but it will really help the rest of the teams substantially.

Originally Posted by Wayne TenBrink

I would go one step further and argue that some amount of unregulated (predesigned and/or prefabricated) components/mechanisms should be allowed. Perhaps 10 or 20 lb (analagous to the withholding allowance) and only on the condition that you share the design and declare the items on the BOM.

Teams would still need to build a new robot every year, but at least they would benefit from the same advantages you get with buying a COTS mechanism. With all the FRC-specific COTS items on the market today, why invest time and money into building something that you can only use once, when you can buy a comparable unit and re-use it? Examples include gearboxes, swerve mechanisms, and now even entire drive modules.

In many cases, using a pre-designed or pre-fabricated mechanism would be more of a detriment than a benefit, because it would involve compromising function for convenience.

The current rules made more sense when every team had to make every mechanism because nobody could buy them. That isn't so true any more, and the FRC-COTS market is likely to grow. This might reduce the artificial exercise of lawyering our way around rules that are not and cannot be uniformly enforced in the first place.

[wilhitern1]

Originally Posted by AdamHeard

Raul posted a similar idea years ago, and I really like it.

Allowing 20 lbs of custom items to be reused year to year won't make good teams any better, but it will really help the rest of the teams substantially.

If I remember the rules correctly... (probably not)... If you fully publish everything about how to build your design. You can then use 100% of it year over year...

Neal

I'll have to go back and check the manual on that.

[dtengineering]

Originally Posted by AdamHeard

Raul posted a similar idea years ago, and I really like it.

Allowing 20 lbs of custom items to be reused year to year won't make good teams any better, but it will really help the rest of the teams substantially.

In general I'm pretty good with the idea that everything is designed, built and programmed during build season... the designing, building and programming is done based on what you learned in the off season, and might be really similar to something that you've built before, but I like the simplicity of the rule.

Where it did bother me, though, was in the needless waste of certain items, most noticably bumpers. We'd do it... we'd slice up new plywood, purchase new pool noodles, buy new fabric and label it (or not) as required. It wasn't a big waste when we only needed one set of bumpers every year, but it did seem a bit needless to build two sets every year when they could have been cut down or modified.

So from a game persepective, I'm good with the rules as they are, but from a cost and waste persepective, a modification of this type makes sense.

Jason