grizzli mini-mill: hard slides

Hi everybody,

I just got my Grizzly mini-mill, and the slides are incredibly hard to
move. I need to apply almost 10 pounds on the handle (if it is in the
left/right position) to get it to move.

I checked, and they are not locked.

Is this normal ? Will it loosen up with use, or should I adjust the
slides ?

bruno