Pathfinder VS ultimategoal

hey, i just figured i’d put this out here in case it helps: meccanum wheels, by nature, have a LOT of slip - that’s how they’re able to move in any direction. i’ve had quite a bit of experience with the math and kinematic behind this (two libraries i’ve written/am writing, Pathfinder and Pathfinder2, as well as a library the other programmer on my team wrote, OdometryCore) and it’s VERY HARD to accurately track the position of a meccanum robot only using the encoders in the wheels. it’s not impossible, but it’s very, very challenging. the more your robot moves, the less accurate it becomes, and it will very quickly report positions that are nowhere near where your robot actually is. you can go for it, but i would strongly encourage you check out three wheel odometry instead - it’s been very accurate and allowed us to do really cool things, like accurately record a robot’s movement and play it back perfectly. you’ll have much more success with three wheel odometry - my team designed a custom odometry system and i’m sure they’d be happy to give you more information if you’d like. best of luck :)

The easiest way that I've done this is by setting the ZeroPowerBehavior of the motor to BRAKE, like this: yourMotor.setZeroPowerBehavior(Motor.ZeroPowerBehavior.BRAKE);. It should keep your motor in the same position when it isn't being moved, but apparently it doesn't work for all motors. Here's how we use it if you want to take a look: https://github.com/grizzlybots11918/ultimategoal/blob/136298379e60662888d5bb87680344ff1a63ac98/TeamCode/src/main/java/org/firstinspires/ftc/teamcode/TempClaw.java#L17. We're using FTCLib but I believe the method and enum are the same with the vanilla SDK.