This may not be a problem at all but I thought I would ask as it seems like it would be. I am setting up my new shopbot in my school lab. I have installed the machine and it seems like it is ready to go. However, I am a bit concerned that the Z axis falls down due to gravity until it rests on the table. I see there are springs in the housing but they are not enough to hold the weight of the Z. I know that the manual cautions about moving the axis without power and I know some of the guys on the forums have said that moving motors manually has fried controllers so I wanted to get the ok before I fire it up and have the Z axis fall when the motor shuts down and fry a controller. So, is this normal? If not, what do I need to adjust?