Well... I've successfully avoided this thread until now, but I'm not going to walk away from this one...
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Originally Posted by fox46
I like mechanum, Omni and swerve drives- it makes it real easy to bulldoze through them and get to where you want to go on the field!
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We've not been buldozed much this season, even by very well built 6 CIM tank drives.
Quote:
Originally Posted by fox46
Keep in mind, this is coming from someone who helped pioneer the design and iteration of several omnidirectional drives back in my days with 854 so it's not that I don't like them, I'm just honest-
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For someone who doesn't not like omnidirectional drives, your post has a very different tone. Everything you say in here is stated as absolutes, and it's just not that clear cut.
Quote:
Originally Posted by fox46
Unless you have an awesome driver- preferably one who has experience with RC helicopters, don't even bother with omnidirectional drive unless you're building a practice machine and can allow piles of stick time and endless drills to get their skill level up. Far too many teams build omnidirectional drives and just don't use them to their full capability and if you aren't using them to their full capability then you WILL be outgunned by a skid steer/tank drive.
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This is true of any drivebase, not just omni drives. A well built drivebase does nothing if the drivers don't have practice time on the sticks.
Quote:
Originally Posted by fox46
Secondly, don't even bother with Omni if you aren't using a gyro and accelerometer to take some of the work away from the driver. DC motors always run better in one direction than another and to try and pull off one of these drivetrains without some sort of logic to make sure it is doing what the driver tells it is just setting yourself up for an extremely difficult to drive robot.
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We've never used an accelerometer in our drive code and only late last year incorporated a gyro into the driver-controlled code. The gyro improved the performance of the robot, not the ease of driving.
Quote:
Originally Posted by fox46
Swerve drive- People think that with a swerve drive you have the tractive capabilities of a tank with the maneuverability of Omni- you do not. Each wheel has (at least) one motor. When you start pushing against something, all your weight transfers to your rear wheels leaving your front wheels spinning in the air. Hence, in a shoving match, typically you are only using half your available drive power. Furthermore, the lag time associated with steering your modules is painful. Any lag time slows down your ability to utilize your maneuverability to its maximum advantage and if you don't utilize it to its maximum advantage you WILL be outgunned by a skid steer/tank.
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Pushing doesn't make the wheels leave the ground, getting under the robot (bumper) does. ANY robot that has weight taken away will have less traction and lack pushing force.