Locked omnis

Hello vex forum
Many teams used omni wheels with rollers locked by inserting a screw last season. I presume that they did this as a way to imitate the effect of traction wheels. Is there any advantage to doing so? Does omni wheels actually have more forwards traction with the foam tiles than traction wheels? Furthermore how do I actually lock the rollers without the screws falling out?
I appreciate all of your help.

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Omni wheels do have the best traction of any of the vex wheels. I’m not for sure what the coefficient of friction is with omnis as compared to other wheels but someone else might. As for locking them, the 1/2 inch screws should do the trick. Try something like this.
Image result for vex locked omnis


Do remember that doing this can pottientally ruin the rollers on the wheel and in a small chance actually crack the plastic on the wheel. So be cautious


Hey, woah woah woah! That was my bot last year! Nice!

Locked omnis, as stated, have the best friction. The extra rubber squishing out from the screw’s placement also help to give the bot some additional traction, as the rollers will squish down into the tiles, and give extra recoil from impacts.

I’m a huge fan of locked omnis. I like my bots heavy (for defense and resistance thereof), and locked omnis help to indulge me greatly.


While locked omnis do create more friction than the traction wheels, the most important reason to use them is that omni wheels have a slightly larger diameter than traction wheels because of their rollers, so a traction wheel wouldn’t touch the ground on an omni drive.


That, my friend, is why I’m going all traction lol

Note: if you do this make sure that you can deal with the turning scrub somehow

Now the problem with that is that turns aren’t smooth. You “scrub” the wheels while turning. 2 omnis (on a 4w drive) make up for this.

It just really depends on your specific case, but just be warned. If these concerns need further explanation, I’d be happy to oblige.


I realized that, but luckily my wheels ate only 8 inches apart. They’re really close together on the thing. Dont worry though, the bots stable, and it’s really hard to pus from the side.


I’m not so much worried about you as I am about others who might read this thread down the road, and try to implement that solution, and wonder why it doesn’t work. (I’ve read enough of your posts to know that you know enough of what you’re talking about.)


i would agree with the other people on this topic that locking omnis would provide the best traction, however the issue is that by locking the omni wheels, you are screwing into them, as if you were screwing into Nylock nuts, so they would no longer work as normal omni wheel after the procedure.

Oh dang I didnt think of that.
I’ll edit the post reeeaaaal quick

(Sees thread about super glue as loctite)

Untrue. From my locked omnis, I find that the rollers still work after un-locking them.
All the screws do is jam them up, like blocking gears. Of course, in being too agressivse, I can see where incidental damage may occur.

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How long did you screw them up for?

I actually have them screwed up right now, but when I’ve replaced screws periodically they seem to still function.

Maybe not as much pressure was put onto your wheels.

Oh! Is that why when I locked my omnis my turning was slightly messed up. I did not realize that my turning would be weird, so I locked my omnis before a competition and that messed up my whole autonomous.

If you use locked omnis you should only have 2 in total, using a 6 wheel drive, and they should be equidistant from each other wheel on their respective half of the chassis. This will keep your turning centered.

We had locked omnis for most of the 2nd half of last season, and they still work fine without screws. The rollers just have some thread marks in the corner.

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Did you happen to use the 8-32 screws?
Bc I think you use 6-32 screws.

6-32 screws fall out frequently and have to be replaced. 8-32 screws won’t fall out (at least in my experience).

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So if I had a 4 wheel drive with the first two omnis locked, would I still have to combat the turning issue? Or do I need a 6 wheel drive no matter what.