Level is only a static condition. There's far too much misinformation about it on various forums. I've yet to see where a dead true level condition gives you parallel shafts end to end over the length of the carrige travel. It is a much easier way to get to starting position though. Due to tollerances required to have sliding surfaces, Oil films, Even part material,hardness, cutting tool types and sharpness along with probably a huge ammount I don't know about, These all have an effect on true parts. At best a dead true lathe alignment is a compromise. Once you think your lathe is perfect then grab a micrometer with 10 times the resolution and accuracy to measure your finished parts. Yeah it's a great idea to get your lathe properly aligned. I would always do so. But it can sometimes lead to high levels of frustration. My first lathe was a Emco compact 5 lathe with screw adjustable mounts, I first got interested in proper lathe leveling starting with that lathe. I also own some remarkably accurate Mitutoyo indicators and micrometers along with a really high quality and accurate level. My shop floor is your normal wood construction. I have and could easily prove to adjust this lathe to turn parallel within .0002 over almost 12" One hour later due to expansion or contraction in the wood floor construction and those numbers are out the window. For sure if your using wood wedges I'd change to steel or better yet make your adjustments with metal mounts and screw adjustable. The very best $100 I've spent so far on my shop was buying a copy of the Connley book "Machine Tool Reconditioning". It should be required reading no mater what your interest level is. (no pun intended). The ACCURATE machine tool world is far more complcated than you would think. Or at least I thought anyway.
Pete
