Slow Yo-Yo!

[genralz]

Hi,

I have to construct a yo yo with the GREATEST amount of time to reach the location below(9.38m+/-0.025m) its starting point. Basically it has to be the slowest yo yo not exceeding 60 minutes.

Basic Guidelines:

*No battery or motor powered yo yo's

*.5m*.5m*.5m size limitation before it descends

*Total mass must be more than 0.5 kg but less than 1.0 kg

 

full guidelines here:

http://teacherweb.com/MA/WatertownHigh/Duggan/photo5.stm

 

(under Yo-Yo Rules)

 

Please post all ideas, thanks!

[Klaynos]

So, what makes a yo yo fall?

 

How can you provide a force against that?

[Phi for All]

.5m size limitation before it descends, there's a clue. Some way to get it to make itself bigger once it starts to descend would help slow it down. If the "bigger" part provided drag it would be even better.

[genralz]

yes both great points,

but i want the simplest yo yo to make, simple yet slow

and making it grow is a tip but it doesn't require it to.

[Phi for All]

You can make the simplest yo-yo, or you can make the yo-yo with the GREATEST amount of time to reach the location below(9.38m+/-0.025m) its starting point, but you can't do both. Why do you want the simplest?

[Mr Skeptic]

Does the yo-yo have to go back up? If not, increase drag. Otherwise, concentrate the mass at the farthest from the center that you can as allowed by the size limit.

[npts2020]

It seems to me a good way to increase the time is to have it do a series of bounces while descending where after the last bounce you are at the end of the string. I also thought about some sort of ratchet mechanism but am unsure how you could do it without making the yoyo stop (against the rules).

[genralz]

no the yo yo does not have to come back up, just descend

and i want to make it simple so that if it doesn't work than i can start with a new one.

 

Mr. Skeptic how you recommend me to increase drag?

and npts, bounce? how can I construct those within the boundaries of the rules? Since I cannot use glues or gels to alter the rope.

[Mr Skeptic]

Then, make it as light and big as possible, and the opposite of streamlined. Eg add sheets of paper from the axis to the outside.

[iNow]

What about some sort of pulley system? I'm thinking that you could translate the spin into slower revolutions on the yo-yo through a few gears of different sizes...

[npts2020]

Increse drag with a flywheel of some kind that expands with speed and drags on the string. You should be able to set it at nearly any speed from zero to free fall. I will have to think about how to get it to bounce all the way down the string but it seems to me you could rig a ratchet mechanism of some kind to make it do that instead of stopping.

[iNow]

Yeah, npts... that's exactly what I had in mind... like some sort of transmission or differential gearing... I just am not sure how to implement it.

[Mr Skeptic]

But will the gears help if the whole thing rotates?

[Phi for All]

Then, make it as light and big as possible, and the opposite of streamlined. Eg add sheets of paper from the axis to the outside.

It has to start out at no more than .5m but can grow. It needs some kind of telescoping arms forced out by the spin.

[Mr Skeptic]

IMO it shouldn't spin fast enough to force out telescoping arms.

[npts2020]

IMO it shouldn't spin fast enough to force out telescoping arms.

 

Only if it spins at the rate of the yoyo and isnt geared down. (think about a grandfather clock that uses weights)

 

I haven't decided on the bounce part yet but am thinking it may require more than one spindle or an offset one.

[swansont]

Note: another discussion here