To swerve or not to swerve

[AdamHeard]

Originally Posted by 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-

Vexpro has 3/8" hex broached 15T 12DP bevel gears that are kind of the standard for FRC swerves (starting with 118, then spreading to 1625, 1717, 973, etc...) for a great price.