Ed in Tampa wrote
Hey in the “my growth rings” YouTube video he went over setting up the lathe part of the SS. He said it was the most important part of the SS set up. He mentioned using the set screw in back side of left side way tube foundation.
This may explain a lot of alignment problems.
I'm aware of at least four 'recommended' methods of adjusting the big setscrew in the headrest end of many Marks. Recently we discussed a method that Nick advocated in a Sawdust Session where adjustment of the big setscrew resulted in the ability to swap the 520 extension table from left to right without losing alignment. And another where adjustment allowed the use of straight tube SPT mounts. IMO, these methods do not all consistently produce the same results. The part I agree with is that misalignment of the base explains many alignment problems. Personally, I would not use a method that did not include confirmation of the alignment at both ends of the machine. (I no longer use any method for my own stuff, I found the Double Tilt (DT) Base eliminates the issue completely, so I use a shop made DT on my shorty. Mine is functionally a copy of the factory DT except for the double rack main table tubes, but I suspect other DT versions would produce equal results.)
Note - The best method I used was one advocated by JPG on this forum. I don't know if he still considers it the best, I think there was a later version that involved a laser. To summarize it, he used a router chuck with a countersink as a headstock pointer and an extension table base as a transfer standard. He transferred both the pointer and standard between left and right and adjusted the big setscrew until things were aligned/centered at both ends at the same time. This method produced the best results I have experienced on a system that included a Headrest.
- David
