Hi all, I've built my prusa i3 awhile back and have been using it for almost 6 months. Very happy with the printer's ability to print (as long as you know what settings to tweak). However, my machine keeps on making a constant noise when the Z-axis lowers (See video below). This doesn't happen to X-axis, Y-axis in either direction; only when Z-axis goes down. I've checked the belt tension, screby loxua - General Mendel Topics