Mecanum wheels

My team has a set of mecanum wheels that we have been using for the past two competitions and we’ve noticed that not as many teams that we’ve seen have been using them compared to last year. We are considering going back to Omni because we haven’t been using the side to side feature. I was wondering if other teams found the side to side motion of mecanum wheels to be a big advantage in this game

If you wanted to do a side to side, I think that an x drive would be more advantageous, since it goes faster, also vex mechanisms aren’t the most efficient either.

Just… use omni’s. There are so many better ways then mecanum.

It all depends on what you are doing. If you are a pushbot and will be battling other bots under the fence, the mechanum wheels are a bit stronger than omni wheels, but if speed is your main concern, then an X drive with omni wheels would be better.

If you are not strafing anyway, then going to a tank drive with high traction in the back and omni wheels in the front may work best for you.

Mecanum wheels are like the Adam Sandler of wheels. They’re always terrible but somehow they always stick around

The main reason why they are terrible is because nobody really knows how to use them. In my opinion, if you know what you are doing, mecanum wheels are one of the most overpowered drives.
Here are the pros and cons of a mecanum drive:

  1. Efficiency on space (Compared to the X-Drive)
  2. Easy to Make
  3. Allows Strafing
    Cons (With Solutions):
  4. Very Slow (You can have turbo motors and problemo solvedemo)

With us, there is two of our teams that contain mecanum wheels, and they are so useful! With our robot, even though we have an H-Drive, we contain this certain type of drive that we’d like to call a “gyrodirectional drive.” Basically what happens is that whatever is the direction of the robot adjacent to the fence is the direction that the joystick switches to. If you push the left joystick forward and the robot is facing the fence, the robot will strafe, but if the robot is 90 degrees left to the fence, the robot will go forward. It is useful but we had some occasions of gyro drift that made us lose some matches. So we are either considering using encoders instead, or just not have it at all though.

My son has done a similar thing. He also made code where you can manually switch what is considered the front of the robot since the Vex gyro sensors are not the most reliable. Our teams have found that to be a bit more reliable. The gyro sensors fail too easily for the cost.

I love seeing this type of innovation with the code. Last year, 323Z started the year with a turret that would stay aimed at the net no matter the orientation of the robot.

Keep up the good work.

Agreed, the gyroscope is way too unreliable for competitions, and I would rather pay double, and maybe even triple the price for a more reliable gyroscope that is able to be used in competition that contains little drift. Like, I don’t understand the use for gyroscopes other than autonomous after all of this…

Thanks, and you too! :smiley:

323Z last year made an auto-tracking turret with several gyros last year. They had some pretty advanced filtering code if I recall. They ended up going with a different design in the later part of the season, though, not sure why.

The term the forum usually uses is
“field centric” as opposed to “gyrodirecitonal drive”

There is nothing particularly wrong with the VEX gyro. It is just a gyro and not an absolute compass. Just know the limitations of a type of sensor. If you want to use it google something like “arduino gyro filtering”.

Ohhhh okay, I didn’t know that. Thanks!

That’s very useful, thank you! So does the gyroscope work better if it’s at the center of the robot, or near the sides?

It will work a bit more reliably when at the center of mass of the bot.

As I recall, reliability of the sensors was a factor. Their code was amazing, but their concept exceeded the reliability of the Vex overpriced parts.

Okay, so I know mecanums are super inefficient when strafing, but are they ineffective in normal tank stile movement? I have never used mecanums, but I don’t see why they would be.

@ET phone home yea because of the cantilevered rollers they dont work very welll at that either