If you did something hasty trying to remove the Quill feed pinion
and damaged the external snapring holding the quill feed pinion in place
(under the coil spring housing), go to your local hardware store for a
5/8" external snapring. Dead on fit in place of a 16mm snapring. My X3
quill now goes up and down smoothly. The coil spring has been adgusted
for a more "neutral" effect on the quill. Let go of the quill feed
handle and the quill stays there. I hate it when using a mill and the
quill snaps back up to fully retracted....