Why not to shift?

[IndySam]

The one thing that I haven't seen mentioned that a shifting robot can give you is more precise control.

Those slow speeds give much better control to the driver when making fine movements like placing scoring pieces and the extra power is also better for overcoming scrub at lower speeds.

[LeelandS]

Originally Posted by IndySam

The one thing that I haven't seen mentioned that a shifting robot can give you is more precise control.

Those slow speeds give much better control to the driver when making fine movements like placing scoring pieces and the extra power is also better for overcoming scrub at lower speeds.

I thought about this after I posted.

When we competed at Ruckus and would try to line up and take shots, we would just turn REALLY slowly and hope we got a controllable speed and didn't overspin when we stopped. This would have been much easier had we had a low gear. Low speed and controlled movements. It would have helped us out A LOT.

[Taylor]

Why we haven't shifted in the past:

1. Adds complexity to the design
2. Adds weight to the design
3. Servo shifters can be unpredictable
4. We often don't have pneumatics on the robot already; adding the compressor for one purpose is a poor use of weight/real estate
5. Adds complexity to the programming
6. Adds cost
7. In some games, we don't see ourselves driving far and fast often enough to justify shifting mechanisms
8. Physical barriers on the field reduce effectiveness of shifters
9. We had a non-shifting drivebase done in a matter of days - we could use this for testing, practice, etc.

[nuggetsyl]

I have to say pushing other teams is over rated. If your going to get a shifter to have more pushing power don't waste your time. Best thing to do is keep things simple. Get your robot to do one thing perfect trying to be jack of all will make you a master of none.

[MichaelBick]

Originally Posted by nuggetsyl

I have to say pushing other teams is over rated. If your going to get a shifter to have more pushing power don't waste your time. Best thing to do is keep things simple. Get your robot to do one thing perfect trying to be jack of all will make you a master of none.

I agree that you should master one thing, though I don't think many teams use shifters just for their pushing power. If you have a second speed, it allows you to gear your for a higher speed. This means that you are more effective at solving the game task. In addition however, it also allows you to be able to win many of the pushing matches you will face in eliminations. In my opinion, the shifter allows you to be a more effective scorer.

[nuggetsyl]

Originally Posted by MICHAELABICK

I agree that you should master one thing, though I don't think many teams use shifters just for their pushing power. If you have a second speed, it allows you to gear your for a higher speed. This means that you are more effective at solving the game task. In addition however, it also allows you to be able to win many of the pushing matches you will face in eliminations. In my opinion, the shifter allows you to be a more effective scorer.

Going across the feild at 22 fps and 10 fps will not save enough time for the average team. Slower is faster in the world of FIRST. The biggest problem teams have (i would say 90%) is they think their better then they are.

Look at the last few games where both alliances put up 0 points. Most of them were to worried about shooting fast or shifting to be faster when they can't even score 1 ball/tube. 2010 is a perfect example, you could have pushed 3 balls in and hung and won over 70% of your games.

[MichaelBick]

Originally Posted by nuggetsyl

Going across the feild at 22 fps and 10 fps will not save enough time for the average team. Slower is faster in the world of FIRST. The biggest problem teams have (i would say 90%) is they think their better then they are.

Look at the last few games where both alliances put up 0 points. Most of them were to worried about shooting fast or shifting to be faster when they can't even score 1 ball/tube. 2010 is a perfect example, you could have pushed 3 balls in and hung and won over 70% of your games.

I definitely agree that shifters are overated. They only help teams that are already preforming well(teams that spend time at the end of the build season tuning and practicing with their robot). However, I think that there is little reason to not use shifters this year. Companies like Vex and WCP have made them super easy(and cheap) to integrate into whatever drive you choose to run.

[craigboez]

We went with a two speed 8WD setup last year, geared for 7.3 and 18.8 fps (14:40, 28:35 or 15:48, 28:40 with 4" wheels). This was created using standard AM gears and shifters that we packaged with our own sideplates.

In competition we never used high speed once. I think it was a combination of a) it was too fast for us, and b) with the field divided in half, there was never a time when we wanted to cover a lot of ground very quickly.

This year we're debating whether we want to have one speed or two. We already know we can do it, for us it will be a question of whether it makes sense for the game and whether the added complexity and weight is worth the effort. If we do decide to do it I have a feeling our fast speed will be a more controllable ~10 fps, pushing our slow speed down quite a bit lower than it was.

[Nemo]

We also didn't use our high speed the way we thought we would, but that's because we had a wide robot that ended up being more tippy than expected. We were really happy to have that low gear for climbing bridges and barriers last year. I think last year we were better off with a 5-6 ft/s robot (that can go 12 ft/s but doesn't) than we would have been with a single speed 9 ft/s robot. And I think we would have been no worse off (except in one particular match) with a single speed 5-6 ft/s robot.

If we do shifters this year (likely), then we will be looking at choosing a sane high gear that we can drive comfortably; perhaps 12 to 14 ft/s. And making it stable enough to actually be able to drive it that fast.

Originally Posted by craigboez

We went with a two speed 8WD setup last year, geared for 7.3 and 18.8 fps (14:40, 28:35 or 15:48, 28:40 with 4" wheels). This was created using standard AM gears and shifters that we packaged with our own sideplates.

In competition we never used high speed once. I think it was a combination of a) it was too fast for us, and b) with the field divided in half, there was never a time when we wanted to cover a lot of ground very quickly.

This year we're debating whether we want to have one speed or two. We already know we can do it, for us it will be a question of whether it makes sense for the game and whether the added complexity and weight is worth the effort. If we do decide to do it I have a feeling our fast speed will be a more controllable ~10 fps, pushing our slow speed down quite a bit lower than it was.

[R1ffSurf3r]

We don't shift. I've always wanted to, mainly because I thought it would be really fun, but it seems to have worked out ok over the years.

[z_beeblebrox]

Originally Posted by R1ffSurf3r

We don't shift. I've always wanted to, mainly because I thought it would be really fun, but it seems to have worked out ok over the years.

Being finalists on Einstein probably counts as "OK."

[AllenGregoryIV]

Originally Posted by R1ffSurf3r

We don't shift. I've always wanted to, mainly because I thought it would be really fun, but it seems to have worked out ok over the years.

What was it geared for?

[BrendanB]

Originally Posted by nuggetsyl

I have to say pushing other teams is over rated. If your going to get a shifter to have more pushing power don't waste your time. Best thing to do is keep things simple. Get your robot to do one thing perfect trying to be jack of all will make you a master of none.

Agreed. Single speeds can play defense just as well as shifter.

[JesseK]

In the last 2 years, having a single speed transmission allowed us to actually complete our robot before ship date and under weight. This is HUGE. Do not underestimate this. We've had our best-ever on-field success in the last 2 years because of this. Go listen to Karthik's presentation. Go now! Then come back.

As the coach on the field, at no point in the last 2 years did I WISH I had a shifting transmission to power through a given situation. Sure, it may have helped inherently ease one or two situations on the bridges in 2012, yet the issue was more about the bridge lowerer than the control getting up.

Thus, unless we're climbing some incline like 2010 (and even then, only if climbing the incline provides enough reward) or we're forced to traverse a wide open field like 2008, I doubt we'll do a shifting transmission in 2013.

[Brian C]

Originally Posted by IndySam

The one thing that I haven't seen mentioned that a shifting robot can give you is more precise control.

Those slow speeds give much better control to the driver when making fine movements like placing scoring pieces and the extra power is also better for overcoming scrub at lower speeds.

THIS is a key point. In 2001 we found that a low gear allowed the driver to better align the robot for hanging tubes. In 2012 it allowed the driver to shift into a lower gear and

1) climb onto the bridge with more control

2) Play defense and push an opponent

One other thing we've always done when shifting is to definitely go for the air shifter as long as pneumatics are on the machine for another reason. The servo shifters do work but we feel they're not as good as 'shifting on the fly' as pneumatics.

As far as the driver getting used to it? Driving practice is a HUGE help.