Hello, i bought a yyf one star and i think is defective.
The axle isn’t fixed on the yoyo go up and down inside the yoyo.
I want know if is normal.
Thank you very much for your help.
Post a picture, then we can for sure tell if it’s defective
PM Me if you have a B!ST Tondo F/T
I have a couple 1 star.
Too bad yours is bad.
I would take it apart oil the bearing,new string.
YYF is very good about help.
I don’t know if with the photo is more clear the problem, the axle comes up and down free and is dificult screw the yoyo
Maybe you can see the difference when the axle is down and up
The Onester uses a bolt/nut axle system so it’s completely normal for it to move up and down like that. The bolt isn’t fixed in place and is held in the groove by the cap so there’s a little wiggle room. You can try taking off the caps and putting some tape or paper or something between the bolt and the cap to fix it in place, but the caps are kind of a pain to get back in place.
As long as the yo-yo is screwing together and holding I would just leave it as is. If it’s difficult to put back together then just avoid taking it apart once you get it together. Use a toothpick or paperclip to get out knots.
take the bearing out, and screw it together. it should re-seat the bolt back into its hex home. Same thing happened to mine, easy fix! 
just pull the axle and rotate slowly until it finds its hexxy seat. I would not take the caps off as I hear they are a real beast to get back in.
Thank you for the help! 