To swerve or not to swerve

[shades23]

What do you guys think about swerve drive in this years game?

[Keegbot]

Swerve is a good option, but if a team doesn't have experience making swerve drives than they shouldn't attempt to make it for the first time during the build season.

[cmrnpizzo14]

Originally Posted by shades23

What do you guys think about swerve drive in this years game?

If you have built it before and can pull it off then the maneuverability, speed, and power that it offers should be advantageous. I think that swerve is almost always a great choice if you can build it but the question is just if you can build it.

[Whippet]

We're not using it, due to lack of resources, but I think that the increased maneuverability will be really helpful for avoiding defense and catching balls.

[tanguma26]

I think there is no need of a swerve drive because you can have the same movement using a mecanum drive and if you can pull it off you can have a jump drive so you have agility and still been able to push other robots away.

[Ty Tremblay]

I've always liked 175's clever drive trains. Their 2007 strafing bot was so hard to stop.

To repeat almost everyone above... If you've done swerve before, it's just a matter of justifying the weight of the system. If you haven't done swerve before, design and build one in the off season before using it in a game.

[JamesCH95]

I would be tempted to utilize the advantages of 2spd transmissions over a swerve drive given that many robots will have to both play defense and avoid defense, i.e. I want the ability to go faster than anyone who can push me, and push anyone who can go faster than me (assuming I can get a hold of them in high gear).

[shades23]

I see the advantages with a 2 speed being able to our run defense bots and push around others but if you get someone who can operate swerve drive you can practically get out of all sorts of situations as seen with 195 in 2012 and 1717 D'Penguineers... in almost every year recently

[Nemo]

I'll be interested to see if some of the top teams that usually run tank drive will choose swerve this year. Some of them have done swerve before, so they could presumably bring it back and still get their other business done. For example: 67, 111, 973, 1114, 1986.

[rzoeller]

If your team is using swerve, are you using continuous rotation or fixed rotation swerve modules?

[JamesCH95]

Originally Posted by shades23

I see the advantages with a 2 speed being able to our run defense bots and push around others but if you get someone who can operate swerve drive you can practically get out of all sorts of situations as seen with 195 in 2012 and 1717 D'Penguineers... in almost every year recently

There's no argument against swerve being the most agile drive style, but the combination of acceleration and top-speed offered by a 2-spd+4cim drive is paralleled only by a 6cim drive, and that costs you two motors and a lot of current capacity when you're pushing hard.

Despite constant debate with myself I can't find a better 'bang for buck' than using a 2spd drivetrain. They're light, COTS that won't break the bank, proven, and generally available. Everything you'd want in a drivetrain.

[shades23]

Do you guys think that this is a solid game for one or no?

[Ty Tremblay]

Originally Posted by shades23

Do you guys think that this is a solid game for one or no?

That's up to you and your team. Do the math, weigh the pros and cons, and maybe even take a vote.

Whether it's swerve, tank, mecanum, or something else, the important part is the engineering.

[Tyler2517]

We are running it.
No matter what running a swerve drive will always be a hard decision to make just from the resource draw it has. We go really lucky that we have been prototyping it(making modulates and improving on them) for almost a year. We had planed on making it for a off season event but our mill broke down causing us to have all of the peaces to make 6 modules sitting around. After resetting the modules in a new gear box configuration we are set to start machining it, In fact the mill is set to go live tonight. if we were not to have already to have 80% of the stuff to make it we would not even have thought of running it.

[aldaeron]

#SwerveSoHard

I haven't built one, but I have always wanted to (ask my team). I looked into it quite a bit in the offseason. One of the items that is required (for a Revolution Swerve Style) is a bevel gear set per wheel. I haven't seen these at FRC type stores (AM & VEX). The cheapest place I found them is on Amazon

http://www.amazon.com/dp/B005AVUCJ8/ (straight bore)
http://www.amazon.com/dp/B005AVU6T4 (keyed)

There are a lot of sizes and bores there.

My cautions after doing some research. Compared with other drive styles, Swerve :
- Is more expensive (count up all the miter gears, bearings and sprockets)
- Is heavier
- Is not in the standard WPI library (probably not in LabVIEW either)
- Takes up quite a bit of room in your chassis corners (you have to be able to rotate the whole wheel and all the hardware with it 360 degrees) (it's tall too!)
- Forces a smaller wheel track

A swerve is a significant undertaking and is a potential season breaker (imagine if you can't drive at all!). Make sure you have a backup plan.

Consider your budget and number of team members before committing. Unless you are a huge team it is likely that the effort expended on learning how to build, program and drive a swerve will take away from your other game mechanisms. Essentially the drive train is your main mechanism. Luckily there are some examples (BuildBlitz & Ri3d) to help you build a quick shooter and pickup.

Also not a bad idea to read this from 1114. They address the swerve in some detail http://simbotics.org/files/pdf/drivetraindesign.pdf

I am basing this on the experience of a friend of mine from 1296 who described his experience making a swerve during the build season. It essentially took most of the season's effort. In following years it was easy to do, but the first year and all the lessons learned were tough.

Good luck

-matto-