08-09-2019, 11:38 AM
The "waves" in your finish are most likely caused by chatter (lack of rigidity) in your set up - not your lead screw. A loose gib, too much tool stick-out, DULL tools, tool center height, even how solid (or not) the base your lathe is sitting on is all it takes to set up a vibration in the machine that will give you all kinds of finishes - except the one you want. Feeds and speeds are a big part of that too. Remember as your work diameter changes (lathe) so does the feed rate.
Snug up all of your gibs, start with a good SHARP tool - on center - and keep everything short (up close and personal) and see if you note any improvement in your finish.
The lead screw on my lathe moves just slightly as well when engaging the half-nuts. But there are no "adjustments" available on my lathe to change the alignment of the half-nuts. I don't believe it really matters because I don't believe there is a manual lathe out there that doesn't have some small variation in the lead screw contact.
Snug up all of your gibs, start with a good SHARP tool - on center - and keep everything short (up close and personal) and see if you note any improvement in your finish.
The lead screw on my lathe moves just slightly as well when engaging the half-nuts. But there are no "adjustments" available on my lathe to change the alignment of the half-nuts. I don't believe it really matters because I don't believe there is a manual lathe out there that doesn't have some small variation in the lead screw contact.
Willie