Why don't we have spherical wheels on computer chairs, which would easily rotate in any direction, like the ones in the old mice?

[Commander Kinsey]

Why don't we have spherical wheels on computer chairs, which would easily rotate in any direction, like the ones in the old mice?

[Commander Kinsey]

Here's an idea, imagine two of these, but horizontal:

one 3/4 of the way up a large spherical ball, and the other 1/4 of the way up. The large ball is now encased inside these two, and can freely rotate in any direction, making the chair glide anywhere, without the wheels having to turn round before you can go in a different direction than you did previously. Why is this not implemented in any device I've ever found anywhere?

[chop]

Because it doesnt work well with heavier stuff like that.

[chop]

Because it doesn't work.

[soup]

The "balls' in old style mice (seems weird calling them old) were not load bearing those on a computer chair would need to be.

[Commander Kinsey]

Good point, but see my reply to my original post. Easy to do it with two ball bearing races round the sphere.

[Commander Kinsey]

What about magnets? Repelling the ball?

Or really really smooth metal?

[Colin Bignell]

The balls in ball transfer tables, typically used to change direction between two conveyor belts, can have to bear quite heavy loads, so that shouldn't be a problem. However, I don't see that it is likely to be any better than a large diameter wheel on a swivel castor.

[Commander Kinsey]

Because the wheel on a swivel design gets stuck when it's at 90 degrees to the direction of motion you request. The wheel doesn't want to turn, and the swivel never seems to want to swivel quick enough. I have to exert 5 to 10 times the pressure to make the chair move, which usually means the leverage tips the chair a little, which is annoying. And I've already replaced the wheels with rollerblade type, which is an improvement, but not good enough. It's only on a shallow carpet.

[Commander Kinsey]

Yip, the number of those I used to clean at work. Not quite as amusing as the secretary who ate biscuits over the keyboard. I'd get an email saying simply "I've don it again, th lttr isn't working."

It amazes me in the 21st century we have colossal processing power in a mobile phone, but we can't make a simple mechanical device immune to a bit of dirt.

[Brian Gaff]

Because the mouse balls were not carrying any weight, If you took a mouse apart to clean it you would see a number of sprung wheels inside. The mouse itself ran on on slides under the mouse. The only way the rotation was measured was by the wheels. Same went for track balls. However you can get so called spherical castors, but they are not very reliable, mainly made of plastic that gets scratched. Also I've seen the actual globe bit push out and tilt whatever was on that side. No castors with two wheels and a longer swing arm work best although they do often look a bit odd, they work for heavy equipment trolleys and the like. Brian

[SteveW]

It would elminate the jam and lurch when you try to move and the castors all flip 180° - possibly turning in opposite directions to do so.

[chop]

Not feasible with that much weight on 5 balls.

Doesnt help with the dirt between the ball and what it rotates in.

[chop]

Ball bearings are nothing like what balls under each leg of a computer chair would be.

And ball bearings hate dirt, which is inevitable with what rolls directly on the floor.

[Rod Speed]

The difference is that there isn't a lot of force to change the axis the wheel rotates around and the carpet impedes the change in direction.

Interesting comment in wiki on using those balls for computer chair wheels

[Rod Speed]

Brian Gaff [e-mail] wrote

I thought the same thing, but realised once Colin pointed it out that ball transfer tables prove that thats not the problem.

But no reason why a steel ball can't be used.

Not clear what you mean there.

But still take significant effort to get around a corner so not really very effective for a computer chair where there isnt a lot of force available to swivel the wheel around a vertical axis.

A sphere would work a lot better if there wasnt the problem of the dirt from the floor being a problem.

Even without that, it isnt clear that the sphere would work well on carpet because the sphere would tend to slide over the carpet and not see the ball rotate in its housing.

[SteveW]

Heavy duty spherical castors are used frequently in industry (often the other way up), to carry very heavy loads.

[Commander Kinsey]

I guess this is the same problem as supermarket trolleys veering off and colliding with the shelving or another customer's ankle. Come on engineers, this is the 21st century, reinvent the wheel, it's outdated!

[Commander Kinsey]

I can see the longer arm working better - more leverage, but on a computer chair, sticking further out will run over your toes - ouch!

Where have you seen these castors? I'd like to give one a try if I can get it fitted to my computer chair. And presumably if you saw some cheap plastic ones there are also more expensive metal ones?

[Commander Kinsey]

Are any of those loads dirty? As in as dirty as a carpet?