[Help] Rolling resistance of EV3 Technic Ball Pivots

[SevenStuds]

I'm in the process of planning an air-powered vehicle that should be able to freely slide in any direction on a smooth, hard surface.

For this to work, I thought of using 3 or 4 of these Technic ball pivots to support it:

One of them is used in place of a 3'rd wheel in this Mindstorms model:

Does anyone have any experience with them as to how freely the bearing rolls inside the ball joint? If a light craft was supported on 3 of these, how much force would require it to roll?

Thanks in advance!

[JJ2]

I have used them and they dont have much friction under low load but when you put weight on them they become more hard to rotate but if you increase the number of them they it will obviously become easier to push.

Keep in mind they are just a powerball joint with a metal ball in it.

[Jim]

I think you will need quite some force.

Maybe better to use 45mm Rotacasters:

http://www.rotacaster.com.au/shop/robotic-wheels/index

[SevenStuds]

Thanks for the tips Jim and JJ!

I just saw some of Simon Burfield's videos where he uses those rotacasters. They are really quite something! Thanks!

[Jim]

Thanks for the tips Jim and JJ!

I just saw some of Simon Burfield's videos where he uses those rotacasters. They are really quite something! Thanks!

Yup, they are great.

I was hoping TLG would include something like them with the EV3, but unfortunately they included the metal ball.

Check out the instructions for this model:

http://www.hitechnic.com/models

[SevenStuds]

Check out the instructions for this model:

http://www.hitechnic.com/models

That model is great. Thanks! I saw they even have a 35mm version of the rotacastors. It's a pity that a LEGO version, like the omni wheels Mahjqa used for his metal grudge tank, would have too much resistance.