So, to check the alignment of the centerline, im going to do what i find to be the best method, and thats to fit a test indicator on a bar held in the headstock and sweep the taper of the tailstock. If im perfectly aligned, i should get the same reading on all points of the taper. First, the horizontal direction, front to back if you were using the lathe. Zerod at the front:

And rotated 180 degrees to the rear:

So, the tailstock is .005" too close to the front. Thats easy enough to fix, back-to-front alignment is built into the tailstock after all. Next we need to check the vertical alignment, and this is already known to be off. Same process, zeroed at the bottom:

And rotated 180 degrees to check the top:

Indicator is reading that the taper is sitting .005" higher than the centerline of the lathe, which i found odd. Last time i checked it was .010" higher, but that was before i changed the headstock casting. New one sits higher than the old one i guess. Anyways, now ive confirmed what i need to fix, the question is how. Theres 2 methods i can use for this, i can either make the headstock taller or i can make the tailstock shorter. Making the headstock taller would require me to dismount it and shim the entire thing up to match the height of the tailstock. Im not a fan of that idea, removing the headstock is quite the chore to do, and im not fond of the idea of the headstock resting on a stack of shims. That just leaves option 2, making the tailstock shorter, and thats the move im going to make. It doesnt seem like its a very common move, most people seem to opt for the headstock route with the theory being that as the tailstock base wears they can remove shims from the headstock to keep things in line, but id prefer adding shims to the tailstock for that. Plus, i get to play on the surface grinder this way.

Before anything hits a tool though, still need to do more measurement. Onto the next post!