Gyroscope

[Crash]

i was just wondering.......

you all know a gyroscope? well if you had counter spinning discs on the same gyroscope (not taking into acount the friction etc.) would the net force cancel each other out and it would fall over? or not..........

im in the eprocess of making one now...damn decent brass is hard to find

feedback please

[Pinch Paxton]

My guess is that they would cancel each other out, but I don't actually know.

[SmokingSkillz]

I thimk it would still stand: it stands cos the force is being thrown perpendicular to the axis equally in all directions so having 2 spheres spining in opposite directions should still have the same effect, only stronger.

[Radical Edward]

yeap, the total angular momentum of the system would be zero and it would fall over.

[Crash]

wow cant wait to test this thing out......ill post pics of it once i finish it

[YT2095]

it would still work as if you just had one spinning at twice the speed and same weight or twice the weight and same speed

the dirrection is irrelevent if they`re both on the same axis, the momentum is all that matters.

they do NOT cancel out! you may be sure

[Sayonara]

He said discs SmokingSkillz, not spheres (although I'm not sure if it makes a difference).

 

I'm pretty sure Rad E is right about the total angular momentum being zero YT.

[YT2095]

sadly however it doesn`t work that way in practice

and so I`de have to go with experimental evidence on this one, two opposite rotating discs on the same axis do not cancel out at all.

[Sayonara]

I'm not sure what you mean by "cancel out", but I suspect it's not the same as what Rad E means.

 

They'll still be spinning, sure, but the system angular momentum won't be the same as in a "normal" gyroscope.

[YT2095]

quite possible not as a system as it would entirely and altogether different, but it would still maintain the same stabilisation effect.

[Cap'n Refsmmat]

I think YT is right. It's not the whole net force, it's the force of each spinning disc. They both have a stabilization effect. In this case, a negative and a positive is not zero.

[Sayonara]

Cap'n Refsmmat said in post # :

I think YT is right. It's not the whole net force, it's the force of each spinning disc. They both have a stabilization effect. In this case, a negative and a positive is not zero.

Well, I'm siding with basic physics so you can think whatever you like. Considering YT hasn't actually given a mechanism, just some effects, I have to wonder what criteria you're using to make that decision.

[Cap'n Refsmmat]

Sayonara³ said in post # :

Well, I'm siding with basic physics so you can think whatever you like. Considering YT hasn't actually given a mechanism, just some effects, I have to wonder what criteria you're using to make that decision.

And tell me, why do you pick me instead of the other two or three people that say it would stay upright?

Let's see what happens when he makes it.

[Sayonara]

Cap'n Refsmmat said in post # :

And tell me, why do you pick me instead of the other two or three people that say it would stay upright?

Let's see what happens when he makes it.

I think you mean one person (SmokingSkillz), and I've pointed out already that he proceeded from a false premise. Unless you count YT, although we are already disagreeing so he's not really a valid selection.

 

But to answer your question, you are claiming strawman. I did not "pick you" because you said it will stay upright: I was pointing out that your agreeing with YT was based on unevidenced claims. I can't very well aim a response to you at anyone else, now can I?

 

And I can tell you now what will happen - it will rattle around a bit, skitter away, and "fall over" (if a gyroscope can do such a thing).

[Cap'n Refsmmat]

Sayonara³ said in post # :

But to answer your question, you are claiming strawman. I did not "pick you" because you said it will stay upright: I was pointing out that your agreeing with YT was based on unevidenced claims.

You have no evidence either, unless you tried it.

[Cap'n Refsmmat]

whoops, I just googled it. http://www.ph.unimelb.edu.au/staffresources/lecdem/mi7.htm

I was wrong.

I did have perfectly good reason to believe it, though.

[Sayonara]

Cap'n Refsmmat said in post # :

You have no evidence either, unless you tried it.

It's called PHYSICS.

[Crash]

well i guess time will tell, im half way through the second one (the first one broke) although im inclined to go with Sayonara on this one

[YT2095]

how is it then that 2 gyroscopes can be stacked even if they spin in opposite directions?

we`ve done it as kids

[Pinch Paxton]

I guess the centre pole stabalizes the whole thing. 1 centre pole cannot lean to balance two fluctuating weights, but two centre poles work individually. Like a tornado, which leans to balance itself. It leans to the heavier side, but by the time it has leaned, the heavier side has spun to the other side. Its juggling the weight.

[Radical Edward]

YT2095 said in post # :

how is it then that 2 gyroscopes can be stacked even if they spin in opposite directions?

we`ve done it as kids

 

because they are not attached to the same rigid straight pole. Just try it, you'll see what I mean.

[Pinch Paxton]

I said that already.

[Radical Edward]

that pert was right, the rest was a little off though. Iam not so sure whether the tornado example reallz works, but it could be a gyroscope effect, I will have to think about that. The real reason that a gyroscope turns slowly around an axis perpendicular to the ground (parallel to gravity) is to do with torque on the body. The following site explains it quite nicely, so I won't go into it in more detail here.

 

http://www.howstuffworks.com/gyroscope.htm

[Crash]

but im not having one straight pole in the center its gonna be two (some problems here)

[Pinch Paxton]

You could try something bendy instead of two poles. I was thinking about the tornado, it's like lots of gyroscopes with a bendy middle. That would be really cool made from metal. I can imagine it as a sarealistic weapon with jagged edges in a movie!

 

Pincho.