hi guys i have i've just got this mini cnc router and i've encountered a very wired problem the z axis doesn't move when its near the end portions of the y axis in a sense it only moves when it's within the middle portion of the table.. which makes up for a 1/4 of the total working area of the router once it leaves that spot it starts acting wired( just shaking slightly up and down) and eventualy the further it gets it only makes a high pitched noice without any motion the other two axis work just fine from end to end.. if aanyone has an idea of why this is happening pls share your thoughts..