Team 2471 swerve drives

[Ether]

Gdeaver alluded to the importance of swerve/omni Driver Interface (DI), and that segues into a question I've been wondering about lately.

Does anyone know of a team who has implemented a DI mode I will call¹ a HaloAR (AR=Auto Rotate), as described in this thread posts 5, 6, and 9?


¹until someone informs me that such DI has already been named

[yash101]

I'm not trying to grief here, but 28 pounds for the drivetrain sounds horrendous! I do not know how much our mecanum drivetrain weighed, but I know that it is well under 28 pounds!

[Bryce2471]

Originally Posted by yash101

I'm not trying to grief here, but 28 pounds for the drivetrain sounds horrendous! I do not know how much our mecanum drivetrain weighed, but I know that it is well under 28 pounds!

I'm not sure where you got the 28 lb figure, but that is irrelevant. This is one of the lightest swerve drive train that i know of. The point is not to be lighter than a mecanum drive. The point it to out preform a mecanum and try to stay as close as posible on weight. But, in some ways you are right, one of the disadvantages of swerve drive is the weight.

Look at it this way, there's over 15 lbs of motors. Maby someone will point out that there is a swerve that weighs much less, and prove me wrong.

[yash101]

The first post shows it on the weighing scale.
Also, mecanum gave all the performance we needed. Your robot gets as good as your drivers get. Crappy drivers and a million dollar robot would be worth pennies. Great driver and ten dollar robot would make the robot worth millions, (if you think of it in money). In this case, the money is the points!

Also, doesn't swerve have a high latency? As of what I know, holonomic drive can have very little latency

[MichaelBick]

Originally Posted by yash101

Also, doesn't swerve have a high latency? As of what I know, holonomic drive can have very little latency

A good swerve doesn't have high latency, though it will have a bit.

[DampRobot]

Originally Posted by Bryce2471

I'm not sure where you got the 28 lb figure, but that is irrelevant. This is one of the lightest swerve drive train that i know of. The point is not to be lighter than a mecanum drive. The point it to out preform a mecanum and try to stay as close as posible on weight. But, in some ways you are right, one of the disadvantages of swerve drive is the weight.

Look at it this way, there's over 15 lbs of motors. Maby someone will point out that there is a swerve that weighs much less, and prove me wrong.

If your swerve really weighs 28lbs (which I doubt includes everything, but nonetheless), then it's extremely light. 28lbs is a pretty decent weight for a WCD, at least in my book. If your drivetrain's over 40lbs (not including electronics), only then might weight be a potential issue.

Oh, yeah, one more thing to add. It's been said many times before, but not in this thread (at least as far as I can see). You've probably already figured this out, but swerve is a ton of work, not just in terms of design or programming, but also in terms of raw manufacturing time and effort. Be careful before you decide (especially before the season) that because swerve is so awesome and you've done it in the offseason that you should do it in-season. Just in terms of manufacturing and assembly time, you could essentially free up enough time to do a full manipulator iteration in season by choosing a WCD or an off the shelf drivetrain over swerve.

All in all, cool swerve, and it looks like you've had fun building it! Congratulations, you've succeeded where many have failed.

[Gdeaver]

No, it's even more. Add the motor controllers and wire to that weight. Yes, there is a big buy in for swerve. For this reason I would tell the largest majority of First teams to look at the cad models and learn but, do not do swerve. It is not for you. Perfect a 6 wheel drive and devote the rest of the teams resources to scoring mechanisms. There are a few teams that have the resources and ability to pursue swerve or other complex drives. The poster appears to have the capability and commitment to do swerve. The rewards can be big. Putting aside the competition aspect of swerve and think how much knowledge and skill a swerve project can give students.
Yes, swerve does affect the weight budget of the robot. That leads to another favorite subject of mine. How do you build light weight strong structures to make up for the weight that was put into the swerve? Composites. I try my best to get as many students as possible to assist in at least 1 composite project.

[yash101]

If done correctly, mecanum will also get the same things done. Our robot was able to push the other robots around at competition. With locking mecanum, we will be able to stun the other teams when we enable it and sideload ourselves, making it impossible for us to be moved! I will inquire about how much our drivetrain weighs tomorrow, when we have robotics.

[MichaelBick]

Originally Posted by yash101

If done correctly, mecanum will also get the same things done. Our robot was able to push the other robots around at competition. With locking mecanum, we will be able to stun the other teams when we enable it and sideload ourselves, making it impossible for us to be moved! I will inquire about how much our drivetrain weighs tomorrow, when we have robotics.

Not quite. There is no real replacement for traction and a second speed.

[yash101]

Locking mecanum makes your mecanums into regular solid wheels, giving you a greater traction.

If you want traction, here's what to do next:
A claw drive system that uses claws to pull the robot along. Things can easily get impractical

[MichaelBick]

Locking mecanums doesn't change the interaction between your wheels and the ground(traction). Swerve can run much higher traction wheels. Furthermore, it still doesn't change the fact that a swerve can run two speeds.

[Ether]

Originally Posted by MichaelBick

Locking mecanums doesn't change the interaction between your wheels and the ground(traction).

Yes it does. He's talking about locking the rollers. See posts 5 & 50 of this thread.

Swerve can run much higher traction wheels.

You can make mec wheels out of high-traction material if you've got the budget to do it.

[MichaelBick]

While being pushed from the side it does increase traction, however from what I understand it does not increase traction while pushing head on. Regardless, swerve can run super grippy wheels that mecanum cannot(2" wide rough top).

[tickspe15]

Where is the 28 pound number coming from. OP says it weighs 37 pounds in his first post.

[Andrew Schreiber]

Originally Posted by yash101

If done correctly, mecanum will also get the same things done. Our robot was able to push the other robots around at competition. With locking mecanum, we will be able to stun the other teams when we enable it and sideload ourselves, making it impossible for us to be moved! I will inquire about how much our drivetrain weighs tomorrow, when we have robotics.

Congrats, go start a thread on it so I can go grief about how my 8wd will weigh less than it… Seriously, are you contributing anything to this thread other than your infatuation with your drivetrain? There's a million threads about people talking swerve vs mecanum, go necro one of those.