I'm a scrollsaw novice and find that my blades break or pop out of their clamps after every few minutes - even at slow speed and slow feed rates.

The blue GMC has little yellow plastic knobs to tighten the blade-clamps and I need to use pliers to get these even close to tight enough.

Now, the problem seems to me to be that the blade does NOT travel straight up-and-down, vertically, but has a slight to-and-fro rotation as the arms move up and down (looking from the side). Nothing I do seems to effectively remove that "blade wriggle". Mind you, the plane of the cut seems perfectly vertical.

I've stripped all the panels and fittings to look for adjustments but cannot find any. Can anyone help me?