What is the best way to mount odomentry wheel?

I’ve set up the forward/backwards odomentry wheels but I could find a reliable way to do the side to side wheel. Since I always need it to not move side to side while going down to make sure it always falls in the same place. I couldn’t find anything on how to do this on the vex forums.
I was thinking of using linear slide stuff but I know that can wobble a bit and setting up the track could be difficult to do it from 2 sides. (Considering I would have nowhere to brace it on for 1 side)
It would be great if someone can give me a concept/idea.
(I don’t want CAD/vids because it’s more fun to optimize myself)

The way i mounted mine was using a screw joint as a pivot between the wheel setup and the chassis and using rubber bands to push the wheel into the ground

1 Like

I’m using the same thing for the fwd/rev odomentry but I was wondering what the best thing to do for side to side odomentry. I think I’ve got a concept I’m going to try it out. passive chain bar on 2 sides and a bar running across the 2 and then mount the wheel on the bar between the 2 chain bars.

How would this be better than a simple screw joint?

This sounds more like you’re doing some kind of lift. (chain-bar is a type of lift)

Are you thinking that you need to have the 3rd odom wheel able to move side to side within the robot? I’m confused why you’re getting into all this complicated stuff with sliders and chain. A picture or a CAD would be helpful to better understand what you’re trying to do

Okey heres my cad of it
Screenshot (72)
I would just connect it to the other side of a chaing bar to make sure it stays level at all times. So If I’m off the ground there is no chance of losing contact because it will always stay level meaning no metal from the assembly could touch the ground either.
This should work and I have plenty of space to mount this on the chassis

It would be passive and default to the down state with rubber bands

I’m just wondering why this is necessary. I see no reason to do this over the much simpler method with a screw joint

1 Like

With a screw joint the wheel would move side to side slightly which could become a problem if the wheel contacts the ground at a different height. This wouldn’t be a problem during auton but during skills it has to be accurate so much longer I’m not going to to take chances with it being misaligned slightly.

Ok. This can be pretty much entirely fixed by using bearings and spacers to reduce slop, but do what you want

1 Like

Screenshot (73)
Quick scetch of what would happen for single bar/4 bar. both would have same motion

No it doesn’t?

2 Likes

Slighty moves over so that’s what I mean by it moving side to side

If you’re using the same stainless steel 8-32 torx drive screws as I am and making a proper screw joint with them you will have virtually 0 slop

2 Likes

I guarantee you will have more slop with the chain bar mech

2 Likes

the cad was of the side to side wheel
Screenshot (72)
*I need to have it not move side to side
*Stay same rotation no matter how high it’s of the ground
So a setup like this should work. Also Slop won’t happen if everything is spaced out correctly

≈0.182” shoulder screw-metal- keps (or lock) nut-Teflon-thing you’re spinning-Teflon-metal-Teflon-nut

codeBot-4-24-2020

Where are you seeing a 4-bar type motion in a setup like this?

4 Likes

@9935E My guy this option literally has less slop lol

1 Like

There would be no slop because the wheel is directly spinning the optical encoder and the chain bar would be passive so it doesn’t matter if it has some slop but I doubt it would in the first place