I got my PGM today but I noticed that the hubstacks keep spinning even after I bind and stop the yo-yo. This is normal, correct?
Also I found out that my axle randomly got loose. I just put it back into the spacer and screwed the yo-yo back together and it stuck back in … should I be worried about that?
Yes, the bearings on the outside will keep spinning until they are stopped or when they run out of juice.
About the coming loose part… Some yoyos do that. Mine dont but Ive gotten into the habit of test twisting it almost every throw just to make sure it doesnt fly apart.
The scientifical explanation of that is that the hubstask are spinning at the yoyo´s speed, so after the yoyo stoped spinning the inertia will make the hubstacks want to continue at the same yoyos speed.