[How do I?] the chicken and the egg situation

Also, keep in mind that .002 is less than the width of a human hair----having said that, have you chucked up a round item and tried to see if there is any movement in the headstock, if you can't feel it, then put an indicator on it just to be sure.
olcop
 
Buster, first get the lathe on firm footing and level it as best you can. Next do a 2-collars cutting test. Search for it here if you don't know what that is. Once you've got that done to your satisfaction align the tailstock to the headstock. Again, search for that if you need to as that's been discussed here as well. Good luck.
 
I feel the need to point out, for those who may find it interesting, that eggs predate chickens by eons. :)

I bought an MT3 test bar on eBay from AtoZ tools (outfit that ships from India, directly from their factory). I don't know of any better way to verify the condition of the headstock (along with RJ's recommendation to indicate the actual spindle taper; use an inspection scope if you can get your hands on one to visually verify the condition while you're at it). The test bar is just a precision ground morse taper on one end and 12" or so of parallel ground bar that extends from it. If it has runout there's something wrong with the headstock somewhere. If it is not parallel to the bed you can go from there to determine if it's headstock alignment or bed twist. Then when you get to the point of tailstock alignment you know that you only have to correct its offset, and not bed twist. Minimize your variables by starting at the headstock and working from there. No sense creating a twist in the bed while trying to correct for what is actually a headstock (or, in other situations, a tailstock) issue.
 
You can make the checks needed with an indicator.
First, the indicator will be mounted on a bar at least 8" long and rotated while mounted to your lathe spindle.
It can be clamped in a chuck or collett.
Soo, you'll need to make certain that the bar and indicator won't sag or have other errors.
Simply chuck the bar with indicator close to the lathe spindle, indicate to the inside of the tailstock spindle with
all locks snug on the tailstock. Record the readings.
Move the bar out 6" and set the tailstock back the same, read again. Since any bed twist will be too small to register in such a test, unless it's a pretzel,
you will see any misalignment of the head.
Don't worry about reading on different areas of the morse taper. Your only looking to see the difference in the sweep readings.
This will show lateral and vertical alignment problems.
I must agree with others that the footing needs to be better.
Just a piece of 3/4" plywood to spread the load out with some 4"x 4" x 1/4" thick plates will make a large
improvement in the setup.
 
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