We had a survey prior to the regionals on shifting gears or not. About 3/4 of the respondents felt that shifting was valuable. Now let’s see what the winning robots actually did.
Of the winners in the regionals and the championship divisions, which robots shifted gears and which didn’t?
If you did shift, what method did you use?
If you didn’t shift, how did you overcome any possible handicap that caused?
Wildstang does not shift gears. We have it set in software so that the Speed Controller isn’t running the motor at full speed when driving unless you are pushing a button. We dubbed this a Turbo" Button. This shouldn’t be confused with a true geared transmission because it’s just done in software and does not change the gear ratio.
No shifting here either. I think the reason we were able to do so well was a mix of the power and traction our robot had, and the strategy we used in our matches. But most of all I would say we did so well due to our driver. Every match he did basically the same thing, and doing this allowed him to become really good at it.
384 didn’t use a gear box that allowd for shifiting of the gears.
45 has shifted gears since 1999 and we continue to do it today. We’ve progressed from using the standard FIRST provided gearboxes for shifting to designing our own custom shift on the fly transmissions (used in 2002 and 2003).
2003:
http://www.chiefdelphi.com/pics/bin/1045537599dscf1904.jpg (expect a white paper this summer)
2002:
http://www.chiefdelphi.com/forums/papers.php?s=&action=single&paperid=78 (our first shift on fly design)
2001:
http://www.chiefdelphi.com/forums/papers.php?s=&action=single&paperid=21 (back to back motor design)
2000:
http://www.chiefdelphi.com/forums/papers.php?s=&action=single&paperid=9 (149669 download(s) :yikes: )
Well, we weren’t a division winner, but we were division finalists. We used a custom 2-speed transmission on the CIM motors, just like we used last year.
Our robot was able to shift on the fly. If was really effective, expecially when teams that didn’t scout robots, thought that we were only speed and no power. We had a high-speed gear and a low gear at a 3 to 1 ratio. Even though we didn’t win, we had a eliminations appearance, a semi-finals twice, and we were a #1 seed in galileo.
We were the finalists at 2 regionals and the semi-finalists in our division at Nationals.
For the past few years we have mounted servos overhead of the drill motor’s gearboxes.
It seems to work fine once you find all the bugs 
We had shifting capabilities, but we found that we could push most robots simply by building momentum in high gear. By backing up and ramming, we were able to knock even suctioned robots off the ramp.
I see many people here saying “We didn’t win, but…”
The author specifically stated people that won a regional. The fact that you shifted and still didn’t do well, complements the arguments of the people who are against shifting. You’re digging yourself into a hole here.
If you look at all 3 national winners, none of them shifted. Obviously an optimized non-shifting robot is far superior to a shifting robot. Less that can go wrong.
I disagree (somewhat). Just because the winners didn’t shift doesn’t mean that the best robots are those that don’t shift. While the winning robots were all incredible machines, there is more to winning than simply your robot (for example skill and experience of driver).
We were winners along with 25 & 102 at rutgers & i don’t believe any of us shifted. 25 used 4 motors for both speed & power. We along with 102 both went with good speed, good traction, & 1 gear. Sometimes, having less to think about can be better. The only times torque to speed change could have helped was getting to the stack, & getting to the top. The thing that really made a difference was a teams ability to do an auto-mode well, or even consistant. And knowing how long it would take to get on top.
When we won the Central Florida Regional, our robot couldn’t run in our high gear (We also changed the transmission 11 times but thats a different story). For chiago and nationals we were able to shift on the fly.
This year team 254 shifted. We used servos to shift the drill transmissions. In low gear we went about 3ft/s and in high we went about 9ft/s. We made it up the hill during auton from 3.5-3.8 seconds. We won SVR (with 115 & 852) and were the finalists at Sacramento (with 599 &256). However, our partners did not shift at either event. At Nats, we paired up with 27 & 192. 192 shifts as well, but I believe 27 does not. We made it to the semifinals.
Last year (I know this is about this year) we used a shift-on-the-fly transmission with 1.5ft/s in low and 13ft/s in high that coupled the drills and the CIMs.
662 does not shift and we were part of the winning alliance at Sacramento. We are geared for about 9 fps. I think that we would have done better at the championships if we were geared lower or could shift.
Team 647 did not shift this year but we are working on it for next year. We won lone star and were quarter finalist in the Archimedes Division.
294 was a regional finalist but we did not shift gears. There are several reasons for this. One: We used our servos as shelves in our stackers. Two: If we were in high gear, if we could get enough torque to move, we would still go FAR to fast (I’m talking about 30fps).
IRON LYONS Team 912 - Canadian Regional Champions (this was the 2nd-annual Canadian Regional) along with rookie Canadian team 1088 S. W. A. T. T. and Delphi-sponsored 378 The Circuit Stompers.
Our robot, S. D. L., does not support any gear-shifting; we had our motors set to low gear all throughout.
I think it was more the strategy of our alliance’s robot combination that took us to the top. 378’s was one of those that could be classified as fast and compact; it went up the ramp in autonomous real fast and real smooth, spanning the entire width. 1088’s was a slow-moving ultra-torque-&-traction-loaded brick that could bully any bot it wanted to. 912’s (ours) was a mediocre bot that had pretty decent torque and speed that could stack, re-orient, and bulldoze with a front-arm that goes down.
378 was reliable for autonomous, 1088 was reliable for king-of-the-hill, and 912’s bot partnered up with our skilled driver, made it strategic in both offensive and defensive play.
The rule of thumb, therefore, I suppose, is to have a combination alliance consisting of slow, mediocre (but ability to multi-task), and fast robots. (one of each type).
Verdict: No need for gear-shifting! Although I think 378 had support for it, they were always menacing around in top-speed, so I don’t believe they ever used it much.
may I ask a slightly different question?
how many teams out there (besides 45, everybody knows about them) shift gears while using a 4-motor drive? (and did it work reliably?)
We, the Techno Ticks, did not shift either.
