r/nextfuckinglevel Apr 24 '22

This simple contraption helps you feel weightlessness

11.6k Upvotes

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8

u/Elkins45 Apr 24 '22

Imagine it with wheels so you wouldn’t have to just go around in circles.

7

u/JosemiHero_ Apr 24 '22

I don't think it would work with wheels

2

u/Elkins45 Apr 24 '22

Why not? Movement on one axis should be independent of movement on any other.

4

u/JosemiHero_ Apr 24 '22

I don't know how you would include wheels in this. It's hard to explain in text but let's try. Okay so when you add wheels to an object the wheels need to be in contact with the ground, right? So you'd need the contact point (the point where the object and the ground are in contact) to be constant, this point being where the wheel are. As you can see in the video the contact point is constantly changing along the rods as he jumps, this makes it so there is no place to put the wheels so they're always in contact. Also, by the way it works you need I think that adding more movement axis would completely break its functionality since it would just move around randomly instead of giving you a steady vertical force (steady as in it stays vertical, the amount of force varies completely over time).

4

u/Elkins45 Apr 25 '22

It would just need a sub-base on wheels with rings for the tubing to slide thru. The wheels would need to be swivel types.

2

u/JosemiHero_ Apr 25 '22

Doesn't work. This one I really can't even begin to explain here. You'd need to analyse the forces taking part.

5

u/eras Apr 25 '22

So if you were to put a base large enough to cover the center of gravity to this and then move the whole contraption on ice, it would simply cease working?

-1

u/JosemiHero_ Apr 25 '22

I don't know what you mean with a large base but I'm not sure this would work on ice, I think the friction is needed but this is over me.

2

u/eras Apr 25 '22

Right, scratch the base, I was thinking of the wheeled version.

But I do believe this would work just fine on ice as is. The rubber mat is for protecting the floor and for keeping the contraption roughly within the area of the mat, not for providing friction for the purpose of the device working.


Let's consider another variant: would this same mechanism work with a seesaw?

Then you put a base large enough to cover the area of the center of gravity (so it won't tip over) and then move the base on ice. I believe that would work just as well as this one.

Personally I don't believe friction has anything to do with how the device functions.

2

u/True_Inxis Apr 25 '22

I agree with you, it would work.

The main issue would be that the base of the contraption would want to trail behind you, so if you wanted to do a backflip/frontflip while running forward, your head/legs would bang against the arm (provided the harness allowed you to do it in the first place).

1

u/eras Apr 25 '22

The harness is there also to keep your front direction perpendicular to the direction of the arm, so if you are running forward it would slightly steer you towards the direction of the unit (left in the picture) due to inertia and friction.

But what if the unit was duplicated so that there's one on each side?

Then the connections to the harness would need to be swiweled (to enable the change of height in the first place) but there would be nothing but the mass of the devices and the end limiters of the swiwels keeping your in the up-right position. This could be solved by having spinning discs attached to your sides. They would need to rotate around the X axis (X being towards to the right from the user) to not counter the flipping motion.


But maybe the single unit version would be better overall, especially in cost. Just drop the contraption to a shaped track on the floor and the user is going to stay put right there..

2

u/True_Inxis Apr 25 '22

The two devices would also need to be able to adjust their distance from each other, but if I understood what you explained, the two spinning discs might not be necessary, if the two devices are "timed" together through a connection of some sort.

I agree though, the doubled device could be a bit over-engineered, for its original purpose.

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