Oh yes cooling metal. Isn't it amazing what a difference 10 - 15 degrees makes to the tightness of your nuts... and bolts and bearings and clutches.
Like when you've spent all that time making sure your scope balance is just right (at 25 deg C) but when you've gotten down to 10 deg it appears that it wasn't balance that was holding everything just right, but the "thermal viscosity of synta snot" Of course it only happens when you have your Dec axis about 45 deg to horizontal, your guidescope on top, your 300D mounted, one hand is holding the nagler and you undo the clutch.
