VEX drive train gear train connection

Most VEX drivetrains I’ve seen have a gear train connecting all the wheels, and this has the advantage of mechanical consistency across all wheels. I am wondering if a drivetrain with wheels on individual motors without a connected gear train will be greatly reducing the consistency, or if it’s something that can be mitigated with programming. Am currently trying it out, and it seems to drive well, but will drift increase a lot in autonomous and programming skills? Opinions?

Your autonomous will not suffer; in fact you probably won’t notice a difference. There is no need to go about a programming solution either; people have been using disconnected drives in vex for years. The greatest issue you’d face might be going over the barrier, but even that will be pretty simple. I wouldn’t worry about it.

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TL-DR: You should be fine.

You will always have some amount of drift, using motion algorithms like PID-s, Pure-Pursuit, and/or Motion-Profiling are all methods of reducing and reacting to this inevitable “drift”.

So yes,

Again, this doesn’t mean that other drivetrains don’t need drift mitigation… It is to be expected.

Personally, last time I used a drivetrain like you described was a few weeks ago, my Pure-Pursuit algorithm was an effective way to control it (coupled with odometry)

And as far as odometry-less control, last time I did that was during change-up; A PID worked well.

Welcome to the forums! One of the main advantages of the geared together drivetrain is that when one or more of your wheels loses contact with the floor, the other motors can channel their power towards other wheels that are connected. To answer your question, yes, you can solve the problem of your drivetrain drifting through programming, but I would still definitely recommend you gear your wheels together. To get it to drive straight, configure the left side separately from the right side, and then which ever side is faster, set its speed to 95ish percent but try different speeds until it drives straight. When you go to program, just have it drive both sides simultaneously. Hope this helps!

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I can not speak on individual wheel-to-motor vs gear train; however, we had the same problem with drifting during auton programming. Our solution was friction. Run each drivetrain motor individually and make sure they are all using the same amount of watts to spin at a certain speed. If the motors use different amounts of power, try to fix compression on the wheels in your drivetrain. Also, make sure your axles are not bent.

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