Now that the new rule to only 4 propulsion motors are available, and the differential swervs aren’t allowed just coaxial, and drivetrains only could be of 2 motors per transmission, what do you think would be the better?
My team are discussing if with this new rule the swerve and tank drive could be competing at the same level (We haven’t use a Swerve before) and now discussing about what would be better to get to us, a coaxial swerve or a 2 motor shifter tank drive or something like that? In all our existance we have only used 3 motors CIM shifter, and now a 3 motors CIM reverse drivetrain that we get last season.
If your team has the resources to do swerve, you should go swerve. Nothing short of banning swerve altogether can make tank drive competitively viable at this point.
What swerve gains you is mobility
2022 was a very open field where I think you could have gotten away with tank
but 2023 was a less open field where mobility was very helpful in placing game pieces
I would say go with swerve, having more mobility is very useful in all situations and will let you keep up with the rest of the competition
There’s no need to build a shifting transmission in 2023, even with the 4 motor limit.
The reasons for a shifting transmission with brushed motors usually had to do with balancing pushing power and acceleration. The primary use of a 2 speed transmission was to allow for a “traction limited” low gear for pushing, and a sprint gear for general driving. It was relatively rare (but not totally unheard of) to use a 2 speed transmission as an acceleration aid (low gear specifically to accelerate faster and auto-shift to high, like a car).
With brushless motors, you have so much power that you really don’t need a low gear to maximize your pushing force, and the acceleration of 4 motors would already be pretty close to optimal as well. The gains from a shifting 4 motor transmission to sprint distance would 1. not be that great, 2. not really be seen much in the real world with things like direction changes, and 3. not really be worth the increase in complexity (reliability and wear concerns with shifting components, need for a pneumatics system, etc).
And this is before even considering that you’d be going from swerve to tank just to try shifting. (Though, shifting swerves are not impossible to design by any means)
well, the swerve will do well for this season, apparently.
it seems like it was specifically aimed at swerves, since its four motors.
for a team with no swerve experience, it may be hard to move to it.
my tip is to think twice before every screw you connect.
swerves cost quite a bit, so do consider this criteria.
in your situation, you need to work fast. a swerve would do, and if you want it really cheap, go with 2 motor tank.
There is still a place for tank drive, but it really depends on your team’s resources and ambitions for each game. I’ve seen plenty of teams with bots that are on the simpler side as a whole do well with tank drives. A driver who is confident and well-practiced will dance around a swerve bot with an inexperienced driver any day.
That being said, if you are very ambitious with how you want to play the game, swerve can be a useful tool. We were anti-swerve for many years, largely due to reliability concerns, but moved to swerve in 2022 and won’t be looking back. With the bots that we’ve built these last two seasons, swerve was a necessity to keep the drive base on par with the rest of the robot and allowed it to truly dominate at times.
Eh. You can “get away” with tank in any game, but swerve still provided a huge advantage in 2022. Because you are more maneuverable, you could drive to balls to intake them much faster with than without swerve, which in most cases, is a more meaningful improvement to cycle time that intake or shooter improvements. Swerve also implies the rest of the robot design due to compensating for other limitations. Swerve bots don’t typically need complicated designs such as multiple intakes or turrets and see less of a difference between sameside vs passthough robot archetypes.
The other main advantage of swerve that people didn’t get to see this year is playing and playing against defense. In any game where defense is relevant, swerve will have an advantage regardless of field configuration. In a swerve vs tanks situation, the swerve bot will win the interaction unless the tank driver is significantly more skilled at driving than the swerve driver, which is fairly uncommon. Swerve isn’t very hard to learn to drive (and imo is much easier to learn than tank due to not having to fight limitations of your drivetrain). Swerve allows you to drive into the corners of robots which will cause them to rotate, which usually is the most effective form of defense against any bot without a turret.
On the playing against defense side, the same maneuverability allows you to constantly be moving with purpose, whereas tank drives can be caught facing the wrong direction, wasting enough time to allow defenders to slow you down again and forcing you to react to the defender. Swerve flips the equation and allows you to to have the upper hand because you can quickly do whatever you want to do, forcing the defender to react to you. When the defender is reacting to you, they aren’t slowing you down much .
I disagree here, there are specific instances where a shifting transmission has tangible benefits*, even when considering that we have “High Power” BLDCbrushless direct current motor Motors.
If the robot has a Tank Drive, and the game calls for a “Mix” of Sprint Distances - as in, some are short, others are very long - then shifting makes a lot of sense - especially for a full weight robot.
The biggest advantage would often be in autonomous - assuming games follow the trend from the last few years. “Low Gear” is optimized to dash out to the game pieces in Auto, while High Gear is likely used the rest of the time.
That said, if it’s a Swerve, there’s less of an Advantage, since Swerve robots can move continuously / change directions without necessarily needing to decelerate. Even then, there’s still something to be said for the potential of a shifting Swerve, especially if the game calls for Full Field Cycles and the Modules can be made to shift automatically (and “Pretty” - like, all together), Acceleration Drops off pretty hard once the gearing gets agressive and the robot is heavy, so shifting would likely increase performance, some amount.*
*Realistically, 2-Speed Swerve is chasing “The last 5% of performance” and isn’t worth it, unless the robot above the drive is that good. For a tank, it’s probably like, last 15-20%