Mechanum wheel intake

The advantage with Mecanums/ omni wheel intakes is the ability to drop stacks off w/out having to either push rollers out of the way or lift up to the top of the placed stack to move away.

1 Like

You shouldn’t have to push the rollers out of the way, just spin them in reverse when you back up.

3 Likes

Depending on how your rollers are set up/ where they will be mounted, spinning them in the opposite direction might cause issues when stacking

2 Likes

I would think you have to mount them almost vertically for maximum efficiency.

Literally just put this on a DR4B and that is good. That being said, it takes more motors than a passive reverse stacker and is much bulkier.

2 Likes

we tried this, it actually does not work with omnis because the green “mini-wheels” on the wheel are not parallel, so the cube does not come out cleanly. for this you need the discontinued omnis with only one mini wheel set on them.

2 Likes

I’m gonna be honest it doesn’t look like a good idea

I actually thought of a similar intake, but I don’t have mecanums to prototype. I really liked the idea, though.

Alas, the TT cubes aren’t perfect cubes, and the variants in the cube sides (those little lips on the edges, to be specific) might cause a problem.

That’s why those conveyor rollers are somewhat popular: to account for Cube variances by having a pliable intake.

If you have the materials and time, this unique design is totally worth exploring. You might come up with a variant of it that surprises yourself. :wink:

If only compliant wheels were such a thing in vex

2 Likes

That’s why we made compliant wheels from conveyor belt!

1 Like

This is insane! I bet someone could figure out how to make it work. Imagine a huge tower of mechanum wheels on each side. 4m base, 1m tower scorer (somehow, passive claw?) , 1m claw separater (like the one in the video :point_up_2:) , and 2m mechanum intake. Cool idea though

Why wouldn’t you just use conveyor belts? They are lighter and can most likely move faster. The only advantage I see is the fact that it would be easier to release.

With a design like the one shown above, intaking happens in two stages: first cubes are pulled horizontally in towards the robot, then they are pulled vertically up into the robot to make the stack. A belt can only do one of those things at a time.

Trays get around this limitation by holding the cubes (close to) horizontally, meaning the vertical intake step isn’t needed.

From what Ive seen, a custom mecanum wheel isn’t (for what it is building one is quite simple) too hard to make all things considered. So you would have tour weight and size issue solved, but the mecanum would likely have to be suspended in order to adapt to the irregular block face.

I think they have them but they’re all VEX Pro

Ye those are the ones I was referring to, along with the andymark ones

I’ve tried mechanum wheel intake, they don’t work. Don’t even waste your time on it.

Do you want to explain this? Maybe with pros and cons or pictures of why instead of just:

My robot stuff are all at school so I can’t take a picture and show you what I did. But what I did is like this:
image
In my design, each mechanum wheel is powered by one 200 rpm v5 motor. I used pivot and rubber bands instead of directly bolt the arms to the c channel because I need the system to reorient cubes as well. If the rubber bands supply too much force, it would be hard to reorient the cubes; but if the rubber bands supply too little force, the cubes won’t go up.

Then I found problems:

  1. My general design is dr4b lift with intake system attach to it, but the mechanum wheels are SUPER HEAVY. It’s not impossible to lift the whole system up, but personally I prefer light and simple design.

  2. My plan is to build a robot that’s able to possess 6 cubes, but this mechanum wheels system can only intake 3 or 4 cubes (sorry I don’t remember) before the cubes stop going up. In the experient I did, I even used my hands to supply extra force to the two sides of this intake. I think in real situation, even if the rubber bands do hold the arms that tight, it would be hard to reorient cubes.
    image
    I had to press the arms very hard to make 3 or 4 cubes to go up.

  3. I find it hard to fit this system into goal zones. I kind of gave up on this design after I found out it’s too heavy so I didn’t try to figure out how to fit it into goal zones.

  4. It’s also hard to release the cubes. The stack might fall when the robot is trying to release it. Using ratchet system can be a solution, but they will make the whole system more heavy and complex.

  5. Maybe it is possible to use mechanum wheels for intake, but that obviously requires extra work to fix all the problems mechanum wheel intake system currently have. I gave up the mechanum wheel idea completely after I found better and simpler ways to intake cubes.

I hope the analysis above can help you understand why I don’t recommend using mechanum wheels for intake. Feel free to ask any questions you have.

4 Likes

No thank you so much, I am sure others on the forum will really like this breakdown of why to use or not use this system.

1 Like