Is a shifting transmission really necessary?

[Aaron]

no its not necisary, but it helps. It also allows your team to decide if they want torque or speed during the game.

[Kelly322]

Team #322 shifted (pneumatically) in 2002 (Zone Zeal) and 2003 (Stack Attack). It gave us great speed and power, depending on what we needed at the time. It was a robust design... once the kinks were worked out. LOL. I think we had a really good design. I'm not totally convinced that this year's game needs it, and the extra weight of the trannies is better spent elsewhere. So, is it necessary? No, especially not for this game. Was it cool when we had it? YES!! I still fondly dream of the days of the little diamond-plate-covered Tweetie machine.

Kelly =)

[sanddrag]

I've seen a lot of people bring up the point of robustness in shifting transmissions. The thing is, just because it shifts doesn't necessarily mean it is less robust or less reliable. For us and many other teams, we have made a shifting transmission that has had no failures over the course of the competition and demonstration. We design things to work properly and not break, and I hope everyone else does to. And the end result is they work properly, and they don't break. As long as this step in the design process is taken, anything can be robust enough to not fail. There are plensty of single speed gearboxes out there that have had serious issues, and plenty that haven't. It all depends on the design and the quality of fabrication. Making a gearbox shift does not at all preclude that you will have problems with it's robustness or reliability.

Also, this issue of size and weight has been brought up. A shifting transmission will almost never be smaller or lighter than a comparable single speed, but the difference can be made very small. Also, say your transmissions come out to be a few pounds more. Now, would you really want those extra pounds out at the end of an arm, or don't you think they'd be better nice and low in the base. If you make one thing lighter, you are going to make another thing heavier since the total weight is almost always a constant. So, it is a matter of exactly where you want those pounds to be. And I vote for them to be nice and low in the base.

[Veselin Kolev]

Remember:

The number of moving parts squared is proportional to the probability of something going wrong.

If making a shifter adds too many more moving parts, reconsider your design. Apart from the pneumatic moving parts, there should not be that many more bearings or gears between a one speed and a two speed. However, there are two speed designs that only add 2 gears and two bearings, as in one more moving part. Keep it simple!

[Gdeaver]

I believe that 2005 changed this debate significantly. This year for the first time the kop included a very usable frame and drive train. There is no reason even a rookie team with no resources can't have a robot base driving by at least week 3 or sooner. The implications for the power teams that build more complex drive trains is that if their development and build time drags out into week 5 or 6 they are going to be going up against teams that have been training their drivers and debugging for quit a while. Also by having the kop frame and drive train together early the programming team has something to do instead of waiting to week six and then having to perform miracles. Our drivers and programmer spent week 4 finding the right joy stick control algorithm and tried different wheel traction combo's. The rest of the build team spent their energy on the arm with out drive train distractions. We went to the regional this year with experienced drivers and a debugged solid robot. We were a very resource limited team and we performed very well making it to the finals. I believe our success was directly attributed to the kop drive train. Going forward, I think every team should look real hard at what the investment of time and resource in a custom trans and drive train will do to their project schedule. Does the gain and game justify the expenditure of the resources and time. The 2005 kop changed things.

[sanddrag]

Originally Posted by Gdeaver

The 2005 kop changed things.

Very true for all the points you listed. While the 2005 kop gearbox most likely provided a higher degree of success as a whole, I think it caused an astonishingly lower degree of innovation as a whole, and on a case by case basis in the drivetrain department. You are correct in saying that using a simpler system is a good stategic decision to get more debug time, but even so , I still hate to see teams not strive for more. Many teams made a good strategic decision to use the kop gearbox, and some went on to win events possibly because of that decision. There are so many good things that came out of the having kop gearbox, that I can't really make a case to shoot it down. But all I can say is this: I truly miss walking around the pits and seeing the wide array of custom made gearboxes and drive systems. I really miss it.

And when all the robots have the same frame and the same wheels too, it makes it even less fun to be a pit browser. I have always regarded the frame and drive system as just as important as any other part of the robot. So to me, lacking innovation in those is just as bad as lacking innovation in an arm or manipulator.

When I started in FRC, I thought one of the greatest things about the buildup was that it was not a put together kit. It didn't come with a manual, it did not come with instructions. It was not bought in a store. Every piece of metal was cut, every shaft was machined.

This year, we achieved a higher degree of success as a whole in the sense that nearly every team manipulated the scoring object, and manipulated it well. But that same old smile while browsing the pits doesn't come to my face anymore staring at the same grey gearbox, and the same hole-filled frame rails, and the same 6 spoke wheels.

It can be made analogous to a situation like this. Do you want every highschooler to only pass geometry before they graduate? Or do you want some to only make it to Algebra and others to rise high into Calculus? It is a tough call to make, one that I certainly can't to.

I like seeing everyone being proud of their functioning robot. But I like seeing some teams being proud of thier unique and different robot too. However, I'm afraid these don't coincide, and the latter doesn't come without the cost of others being left with a poorly functioning robot.

There is no way possible to get what I want to see. I have no solution, for what I see as a problem. The problem is I think the Kit is becoming too much of just that, a kit. Where will it go next? 4th and 5th year teams are taking the easy way out by using what they are given, instead of striving for something more.

I think the KOP gearbox and frame are fine pieces of hardware that has made the competition more do-able and more enjoyable for many. But for some like me, the fun and pride in some aspects of the robot and the competition has been taken away.

[Cory]

Originally Posted by sanddrag

Very true for all the points you listed. While the 2005 kop gearbox most likely provided a higher degree of success as a whole, I think it caused an astonishingly lower degree of innovation as a whole, and on a case by case basis in the drivetrain department.

Sanddrag, I still do not understand why you believe that it's so bad that people not go all out and make crazy drivetrains. Why innovate when what you have suits the game perfectly? There's no reason to make a super cool 4 speed 6 motor drivetrain if a single speed, 2 or 4 motor drivetrain will get your strategy done just as well.

It makes no sense to me to go and make a super cool drivetrain, just because it's super cool. If there isn't significant upside to doing something significantly more complicated and time consuming, what's the point?

2005 wasn't a game of drivetrains like 2004, and particularly 2003 and 2002, which the vast majority of the teams recognized and took into account.

As to the analogy to settling for passing HS with geometry, or moving up to Calculus, why take calculus if your career doesn't utilize anything above geometry? Same thing with FIRST. Why waste resources to do something that doesn't fit your strategy and won't give you a tangible advantage?

It's the mark of a good team to know what to use, and when, not to use the most insanely cool innovative feature known to FIRST, just because.

At any rate, I don't think you can conclude "4th and 5th year teams are taking the easy way out" because they use kit parts, because FIRST's mission isn't innovation, it's to recognize science and technology. Innovation can certainly be a part of that, but it's not a necessity. If a team has successfuly used a simple drive year after year, congratulations to them for finding something that works well for what they do.

And mechanicalbrain: Without a drivetrain, the best arm becomes useless 2005 was certainly not a year of standout drivetrains, but the previous three games sure were. 2003 was essentially a contest of who had the most powerful drivetrain, as was 2002 with a few twists thrown in.

[Gdeaver]

Making a gear box shifting or single speed requires precission machining. If a team doesn't have acess to the equipment and mentors with the Knoledge to use them a team before 2005 was at a major disadvantage. To go out and buy the part requires lots of funding. Our team had neither. All we had where hand tools. If the KOP trans had not been in the kit this year, we probably would have used the Fisher price solution and it would have been a marginal solution. I know because we used it before and it"s limitations probably would have put us at the middle bottom of the heap at the regional. The KOP trans this year allowed us to inovate in other areas. Our arm was made out of composits. Pulltrustions, Cabon fiber lay up, and epoxy chopped fiber cast parts. All done with hand tools. OUr arm weighed 23 pounds with motors, the same design in aluminum would have weighed 44 pounds. So there was some major inovation on our team. The Kop trans is a competition leveler. The point of my post was that teams need to realize this and may be pay more attention to where they allocate there resources in the future.

[Hutch]

My team didn't do shifting this year - instead, we went the way of custom gearboxes and a 6 motor drive train. That was great and all, but it drew a LOT of current (over 100 amps at times or so I was told) and it was just two less motors for us to use elsewhere.

Shifting would have allowed us to have the torque when we needed it and the speed when we wanted it, without all the motors and wastefulness of the 6 motor drive train. And shifting doesn't add any driving headache (you just have current sensors and at some threshold auto shift up or down) so if you have the resources, I don't see why you wouldn't want to strive for more.

Not to mention what a great learning experience it is to help design and manufacture one...

[mechanicalbrain]

Cory this is directed at you. its very easy to make a simple drive train because most people will copy a design or buy one. there really is little ground for new creation. i think one common idea held by a lot of FIRSTers is that having a good robot is the complete objective and i feel kind of sad to see that. if we don't continually push the bar than eventually people will find a comfortable niche and get mired in it. in short by doing something crazy like a six speed drive train it shows the team has a true understanding of the given concepts and in doing the extreme they might be inspired to create new designs like the ball drive train. basically it encourages people to be creative something i push for hard. (i don't really feel like being criticized about encouraging impractical designs because if anyone feels like doing so then they really don't understand my post. this is just something i forsee someone posting)

[sanddrag]

Originally Posted by Cory

Sanddrag, I still do not understand why you believe that it's so bad that people not go all out and make crazy drivetrains. Why innovate when what you have suits the game perfectly? There's no reason to make a super cool 4 speed 6 motor drivetrain if a single speed, 2 or 4 motor drivetrain will get your strategy done just as well.

I completely agree. Putting resources into something elaborate when only something simple is required would be considered by many as a poor strategic decision.

Like I said before, I can't really define my point sharply. I can't really make any sort of case or argument against the kop gearbox. I even said it is fine piece of hardware that has made the robot more enjoyable for many.

I have no case or argument against it. All I'm saying is that I like to see kits, rules, and games designed that challenge teams in the area of drive systems. To me, for every team to be handed a beautiful, reliable, and capable gearbox right from the start, instantly eliminated a large part of the challenge in the robot building for many teams. In some cases this was a very positive thing, in other cases I believe it wasn't.

It is very clear that there will never be one set of rules or one set of parts or one type of game that suits every team well. Due to variances in resources, skill, and experience, it will always be easy for some, and hard for others. The only thing I'm trying to say about the KOP gearbox is that I believe it made it too easy for too many. You are probably wondering "why make it hard and have people struggle, wouldn't you rather have them succeed from the start?" Well, the beginning of everything I learned in FIRST, was by helping design and build a gearbox for the first time, and have it fail. And look where I am today. I'm not saying one must fail in order to learn, but I think teams would get more out of this if they had to design their own gearboxes just like in the good ol' days.

Before anyone makes a reply attacking what I say, it is merely an accummulation of some trends I saw, and some ideas I had. I'm not trying to argue anything or make a case against anything. I'm not trying to offer any solutions to any problems. I'm not taking a I'm not really sure where I'm going with them.

[mechanicalbrain]

I agree with Sanddrags statements, and feel them on a personally in the competition. while the KOP is great for teams that don't have the ability or resources to create a custom drive train, it gives the game a standard. However I think it also makes the game more uniform. Our mentors heavily pushed for using the KOP, and our drive train designer was really disappointed at not being able to create our own. I personally feel this more in electronics as we have no choice but to use most of the parts FIRST provides. this leaves me with less of a choice with deciding what pieces of electronics would be cool, and leaves me focusing more on how I can mount the required peaces efficiently and how to wire them. overall electronics is just like putting Lego's together. it really provides no room to grow other than sensors. (i know this because I'm hitting the glass roof with what i can do with our system)

[sanddrag]

Instead of making the build process easier to level the playing field, I'd like to see the game challenge be made wildly differetn and oodles more challenging in order to level the playing field. Make it something no one has done before, and then all will be at the same level, and all will ba challenged.

[Cory]

Originally Posted by sanddrag

Instead of making the build process easier to level the playing field, I'd like to see the game challenge be made wildly differetn and oodles more challenging in order to level the playing field. Make it something no one has done before, and then all will be at the same level, and all will ba challenged.

Even if it's something nobody has ever done, the "powerhouse teams" will all still have a significant advantage, while rookies get left behind in the dust.

Innovation is not a problem. If the 2005 game had required an innovative drivetrain, teams would have innovated, but it didn't, so neither did the teams.

[mechanicalbrain]

Two things. One I think you under estimate the ability of small teams. Second I think that just becuase a game doesnt require that a team to be inovative with something certianly doesnt mean that they shouldnt do it anyway. If we arent always pushing the bounds of our knowledge how can we expect it to grow?