1 or 2 anti-backlash nuts?

Hi, I am new to CNC machines - never run one, but now I own a 30x30 longmill. I assembled the X and Z axes and will start on the two Y axes. My question is, do one or two “anti-backlash” nuts go on the router assembly? The picture showed just one, which is what I have. But there are holes for two and there seems to be an extra one.


-Mike Mac

Hey Mike,

One anti-backlash nut should be on each lead screw. So if you have one on the XZ gantry lead screw and one on the X-axis so far, you are good to go to assemble the Y-axis!

@kellyz - thanks for the quick reply.

So there are a total of 4 needed, but five are shipped - so one is a spare?


There is one anti-backlash nut on each lead screw so there should be four in total. One for X, one for Z and two for Y which has two lead screws.

Yep! You get a spare just in case.