Quote:
Originally Posted by Tottanka
This is all assuming i'm using 4 Omnis in a tank drive style (X movement) with 2 more added at the back of the Drivetrain (Y movement).
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What's the rationale for 2 wheels for strafing? Are they located in the same line? It sounds like they are.
The whole idea of H-drive is that you would like most of the advantages of a skid-steer, but are willing to give up some traction (including almost all of your side-to-side traction) for the ability to "strafe" just a bit, that is, move right-to-left with none or at least minimal rotation, but just enough to "line up" on some sort of target, not something that you're planning to use as you cruise down the field hoping to reach free speed.
The amount of traction you can get from each wheel is limited by its coefficient of friction and the weight on that wheel. Assuming for simplicity's sake that you're putting the same weight on each of your six wheels, you're putting 1/3 of your weight on the strafing axis, 1/3 on the left tank line, and 1/3 on your right tank line. With a classic 5-wheel H-drive, the numbers are 1/5, 2/5, and 2/5. Do you feel that increasing your strafe traction from 25% to 33% is worth reducing your forward/reverse acceleration from 75% to 67%? If so, by all means continue! The next classic step, by the way, is Killough or mecanum, each of which supports 50% forward and 50% strafing.
And, of course - why at the back? I'm assuming you pick up loads at the "front", which may be in error. If you aren't going to put the strafe force at the center of gravity, it is probably better to err at putting it on the side that you actually want to move left-to-right.