no tilt but turn

i have a dark magic 2 n when i do a brain twister just to test it. it turns not tilting but turning what is that??? :-\

It’s precession.

Also please don’t post a poll for no reason. Just make a thread and ask your question.

I’ve never knew a word for it, but I am pretty sure it is either one half weighing more and or one half being slower.

one half can’t be slower. It could be that the weight is just different enough on one side or the string is on the side of the bearing too.

Obviously, I have thought about this before, but I meant when you try to slow one side down. Like throw a sleeper and touch a half, it turns. I also thought about the string being off center causing a uneven weight too. I just forgot about it.

Your string might be pushing against the side causing it to turn. Braintwister you need to be careful to keep your hands right behind the other cause if they go opposite directions it will cause the yoyo to turn

Like Casey stated, it’s precession. You can see this in its not so glorious glory when you do a thumb grind. If you do it for long times, the yoyo will spin around, not sit still, because one side is trying to slow down, and the friction, combined w/ centripetal and gyroscopic forces make it spin around. If you watch some people, some tricks will do the same thing, i.e. gyroscopic flop. The yoyo spins around the string, while still spinning.

I believe that’s right. The yoyo doesn’t stop spinning when put in contact w/ something else, but the friction on one side causes the yoyo to try and spin around, instead of just spinning.

If I’m wrong, somebody please correct me.

what?? lol

Precession is caused by gyroscopic forces, bud. It’s just that other things can make it occur quicker, i.e. the way you execute a trick or doing thumb grinds.

I don’t think you explained it very well. We are all pretty much right. A way to fix it would be developing better sleepers or the yoyo has not enough mass on one side, which would only really happen with a NASTY ding or satining your throw.

Im not too clued up on physics… but…

The law of precession is that a force applied to a spinning object is felt at an angle of 90 deg. to the spinning object?

If you thumb grind - note that the side that is slowing down (where your thumb is) turns away from you. Logically, the side that is spinning faster “should” turn towards you, but this doesn’t happen.

When you thumb grind, you apply a force to the top right-hand half of the yoyo - this force is then transferred 90 deg. to the front end of the right-hand half of the yo-yo, causing the yo-yo to turn on its axis away from the force.

Incidentally, precession is what causes boomerangs to return.

Hopefully someone with more knowledge can plug the gaps in my response…

It’s not spinning faster. That is impossible unless the two sides spin separately. Now there can be a force applied to one side and it can cause drag which in turn will cause teh side with no drag move directional but not spin faster.


I thought “faster” may make it easier to understand - but you are correct, both sides will spin at the same speed. The yoyo turns because the “drag” is felt 90 deg. forwards from where the friction/force is applied - in this case, if you had a yoyo on a desk - it has the effect of you pushing the front end of the yoyo on the same side as your thumb grind, hence the yoyo turning away from the grind.

i.e. Thumb Grinds, Pushing the string against one half (My guess whats happening here)

so can i fix it or is it broke???

LOL, just practicing to get a better throw. It isn’t the yoyo it’s just that your sleeper isn’t very well developed. Just practice.

It’s not broken. It’s all you, most likely. Unless you’ve done a good deal of damage. Could be another cause.

If the yoyo is tightened, it is physically impossible for the two halves to move at different speeds. The only way this is somewhat possible is if you threw a loose yoyo. When two halves move at different speeds, the yoyo will unscrew itself and you’ll have a disaster on your hands.

When you touch your finger to one side, the yoyo “turns” simply because you are applying a slight pressure/force to that side, as small as it may be. By your logic, you are stating that if you grab one half of a spinning yoyo, the other half will still be spinning, which is obviously not the case.

This problem is usually from an axle being slightly off-center or a bearing seat that has been warped over time on one side.

Also, in my experience, a dirty bearing can cause a yoyo to turn. Give the bearing a proper cleaning if you haven’t tried that already, and make sure the bearing seat is free of debris.