My x axis on my Comet is squeaking

A couple drops at the ends of the top slots like in the photos should help. Put the tip about halfway inside the x axis so the drops will fall onto the belt/pulley. You can use a lubricant like one here. 

If you don't have any lubricant on hand, or if that doesn't fix the issue, please let us know your current address at [e-mail] and we'll send you a new x axis!