Hey. I wanted to make this thread because I know it will help me and a lot of people. For this year’s competition (Change it up) which wheel type do you think will be the best?
wheel type is not enough information. you need to also consider the arrangement of wheels.
2 best options are a tank drive setup, with 4 omni wheels, and an x drive with 4 omni wheels at 45 degree angles.
tank is easier and reliable but cannot strafe.
x drive is more maneuverable because it can strafe but it’s harder to build.
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X drive is also generally less effective on defense. It can’t push or resist pushing as well as tank drives. X drive is great for skills and offensive drivers, where tank can be good for defensive drivers in match play or drivers who are unable to strafe effectively
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basically if you’re newer you should just make a tank drive.
chances are, if you didn’t know what an x drive was, you shouldn’t try to build one yet.
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This should just be copied and pasted into every thread from new posters asking about x drive
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What do you think about mecanum wheels? It retains the 360 degree motion of X drives with more resistance, albeit slower.
I think they’re worse, because the turning and bulk of them. But they can’t be terrible given 7k’s performance with them in TT.
What makes their turning ability bad? Sorry, I’m pretty new to VEX.
they don’t turn as smoothly as an x drive. an x drive probably has the smoothest turning of any drive, while mecanums have a bit of skidding when they turn, and I just find mecanum drives to be slower.
but I’m definitely not an expert on holonomic drives, this is just from my observations as I’ve never actually built an x drive and I’ve only built one mecanum drive.
That makes sense, thanks!
My team has never had any skidding while turning with mecanum wheels.
There is a chance I’m incorrect about the turning quality of mecanums given my lack of experience.
it was decent when I built one, not quite as good as an all omni tank drive but not as bad as an all traction tank drive.
Since some teams will be competing in the remote 2v2 game, do you think it would be better to have a holonomic over tank drive?
Xenon don’t forget that 7k had mecs in Turning Point. They sure destroyed us. It was my first year and my robot was awful though (qualified by skills). They got 3rd in skills iirc and went undefeated in science div.
My team went from 278e to 2990b.
Also my friends had a fantastic mecanum robot in TT.
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It seems inaccurate to call any wheel bad, they are just good in different situations and depending on the skills of the team implementing them.
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mecanums can definitely be good if you use them right. I just think x drives are better.
so what is the right way to use mecanum omni’s? I remember reading somewhere they had to be alligned. considering doing mecs because i dont want to do an X drive. X drives at least the ones i have seen seem a little bendy
Key points are
- A rigid frame
- Frame is parallel to the floor, all the wheels must have equal contact.
- Good tolerance on axles you want the wheels to sit flat, you need to support both ends of the axles.
An X or + drive is more forgiving of bad build techniques. But in a game with defense, I’d take the mech wheels over omni all day long.
@Xenon27, I’ve built both types of drives on a number of different sized robots. You should build both and see how they stack up, I think you’ll see the difference.
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Don’t forget the orientation of the wheels. The rollers should point inwards towards the center of the robot in a x-formation.
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