the fan on the top of my z axis seems to cause excessive vibration when running.
It will vibrate tools off of the tool tray and i can see the vibration in an indicator needle if i happen to be using it when the fan is on
is this normal? what's the fix?
I don't think that is normal . Check that nothing has got stuck to one of the blades. I once had a fan pick up a bit of tissue paper on one blade and it shook like crazy.
An open mind is a virtue...so long as all the common sense has not leaked out.