Enco 13x40 lathe alignment

[Clunker1]

I've reviewed a lot of info on lathe alignment to the point where I'm confused.
Leveling has been debunked somewhat as navy lathes are bolted right to deck plates. The geometry is what I understand is most important. Chucking a two collar test bar with about 9 inch extension and making light cuts on the collars should indicate if the ways have a twist.
That seems pretty straight forward but my lathe has an adjustable head stock as well. Seems if you cut a test bar and get a taper, you could also compensate with the headstock adjustment? That might simply mask a ways twist issue.
My question is where to begin. Checking head stock alignment or ways twist?
I dont have a machinist level but saw a video clip where someone jst fabricated a large plumb bob device to check level.

Any insight on this topic would sure be appreciated.

 

[Provincial]

The factory alignment of most lathes with an adjustable headstock is only to move the axis of the spindle in the horizontal plane, toward or away from the operator. While this is an important alignment point, there are several others. Misalignment here moves the bit toward or away from the center of the work as it travels, getting worse as it moves away from the chuck.

The horizontal alignment makes the lathe taper if not parallel to the ways. If the ways are not straight, or are twisted, adjusting the headstock will be unsatisfying.

The ways can be warped or worn in several directions.

Arched or Sway-backed ways are, respectively, higher halfway to the tailstock end, or lower in that area. This causes the tool bit to cut high or low as it travels, effectively moving the bit in and out in relation to the work.

A twisted bed moves the bit up and down, and also in and out with travel.

Worn ways can cause the tool bit to move either up and down, or in and out, or both.

You start by using a straight edge to see if the ways are worn, Arched, or Sway-Backed. You use a level to check for twist. A level can also find the other problems, but it takes a very sensitive level to do that.

There are Master Precision Levels, Machine (or Machinist) Levels, and as you progress into less sensitive, and less accurate levels, down to Carpenters Levels. While Master Precision Levels are desired, many accurate machines have been set up accurately using Machine Levels, with the workman simply being very precise at reading the bubble.

If you level the ways using a good level, it makes it easier to read and interpret any indication of twisting. It also helps in doing some set-up work. I find it well worth the time and effort.

A ship-board lathe my not center the bubble if set up properly, but the bubble will show the same indication if moved along the ways. It is the consistency, not a centered bubble, that counts.

 

[Clunker1]

I should also include the event that i think caused the lathe to taper cut as much as .004 in 8 inches (higher diameter away from chuck while using adead center).
I was attempting to cut threads using joe pizinsky method, tool upside down, spindle in reverse, threading away from chuck. Had a brain fart and engaged spindle forward instead of reversed and crashed bit into part.
Spindle tests ok with no noticeable runout.
This is why I'm wondering if headstock alignment has shifted and need to find a way to diagnose the issue.
I also found an issue where my 3 jaw chuck seems to grip inside edge of jaws and requires significant tightening to eliminate wobble in the jaws. May need to grind jaws. I plan to diagnose lathe alignment with my 4 jaw chuck before dealing with the 3 jaw chuck. The 3 jaw chuck was in use when i crashed the machine.

By the way, I told my crashing story to my retired machinist friend and he just laughed and said "Welcome to machining".