If it’s been modified in the way you describe all bets are off on fixing it. Probably a poor job on the cutting and it’s out of balance or the axle hole got messed up in the process.
Not sure what you’re gunning for here, maddog. You asked where the vibe could come from, and the mods are the most obvious answer. If you don’t believe people telling you that, why ask the question?
The tolerances needed for their to not be any vibe at all are extreme. They’re tight even for “minimal vibe”. I don’t care how good a modder your friend is, I agree that “all bets are off”.
If it had vibe to begin with, the answer is still easy: it was slightly off balance to begin with. And that’s right from a relatively precise manufacturing process.
Without first-hand experience, that’s more or less the only reasonable conclusion to draw based on what you’ve said.
Whether it was originally “messed up” or “B-grade” is a whole other matter. We’ll never know. But it’s worth mentioning that not all yoyos are expected to be smooth as glass even right out of the box.
We’re going in circles. Vibe and wobble are caused by one of three things:
unbalanced halves
axle imperfections (either the axle itself, or the threads machined off-center by a smidge)
Asymmetrical halves
We don’t have a time machine to go back and test its original condition, but if you say it had some vibe, we’ll have to take that as a given. If it had a LOT of vibe, it was already messed up (from the factory, during transit, after receipt, etc).
Then if you mod it, you are exponentially increasing the risk factors for making it get wobbly. That’s all there is to it.
Some yoyos just come with a little vibe. It doesn’t mean that the yoyo is messed up - it just has a little vibe.
Sometimes yoyos just get more vibe. A hard knock, while rare, can give a yoyo heavy vibe.
As for the wobble, I can almost guarantee that it’s the mod. No doubt about it. Any kind of hand reshaping a yoyo is bound to cause vibe. The tolerances required for a vibe/wobble free yoyo are almost impossible to do by hand.
Making a smooth yoyo requires holding NASA level tolerances. .0002" tolerance is required on the bearing post. The other concentrically important parts also have similarly tight tolerances. Modding can easily take a yoyo out of tolerance.
He’s saying that whatever your friend did to it could likely be the cause, as in cutting the shape or as you note the axle hole. You do not have the tolerances needed when cutting manually. Time to write it off to experience.
Vibe and wobble are caused by one of three things: