This is the fifth time I have done all this. This time it was after watching a master do it.
My PM 1340 GT went in a newly built garage last year. Now the lathe is only 1350lbs on the stand, but still, new concrete can settle some.
The first thing I did was calibrate the level. That showed me the lathe had settled quite a bit. I worked on it for 3-4 hours in between some other stuff I had to do. I would make an adjustment, let it settle for a bit, and recheck. The PM 1340 GT is light and stiff, so it resisted untwisting. I got it close then left it overnight. In the morning it was very close and only needed some minor tweaks.
Then I checked the headstock. I found a 12" piece of 1.25" aluminum rod. I chucked it up in the three-jaw with 6" sticking out. I made .005" cuts--it took three to completely clean up the rod. I measured with my Mitutoyo 2" micrometer and discovered the headstock was .002" out over 6".
So I took the time to figure out how to adjust the headstock. Along with the micrometer you need these tools for the PM1340 GT:
This took a while. You lightly loosen four headstock retaining bolts, loosen an allen head screw that locks the adjustment, then make a minor adjustment on one of the two headstock alignment allen head screws. Then you have to make another very light test cut on the bar in the chuck. When I got it done, it looked like this:
So that is .0003" over 6". I would have been happy with .001" over 6". This is an engine lathe, not a tool room lathe. I don't know if it will keep that level of alignment.
Then on the the tailstock. It too was out a couple thousandths, maybe more. Here is how that turned out:
The Edge alignment bar is very accurate. We validated it on another lathe after sweeping the tailstock with an indicator in the chuck.
I don't know if any of this will make my LRBR rifles shoot any better, or if my tenons or chambers will be any better. However, this is as good as I can get my lathe I think.
My PM 1340 GT went in a newly built garage last year. Now the lathe is only 1350lbs on the stand, but still, new concrete can settle some.
The first thing I did was calibrate the level. That showed me the lathe had settled quite a bit. I worked on it for 3-4 hours in between some other stuff I had to do. I would make an adjustment, let it settle for a bit, and recheck. The PM 1340 GT is light and stiff, so it resisted untwisting. I got it close then left it overnight. In the morning it was very close and only needed some minor tweaks.
Then I checked the headstock. I found a 12" piece of 1.25" aluminum rod. I chucked it up in the three-jaw with 6" sticking out. I made .005" cuts--it took three to completely clean up the rod. I measured with my Mitutoyo 2" micrometer and discovered the headstock was .002" out over 6".
So I took the time to figure out how to adjust the headstock. Along with the micrometer you need these tools for the PM1340 GT:
This took a while. You lightly loosen four headstock retaining bolts, loosen an allen head screw that locks the adjustment, then make a minor adjustment on one of the two headstock alignment allen head screws. Then you have to make another very light test cut on the bar in the chuck. When I got it done, it looked like this:
So that is .0003" over 6". I would have been happy with .001" over 6". This is an engine lathe, not a tool room lathe. I don't know if it will keep that level of alignment.
Then on the the tailstock. It too was out a couple thousandths, maybe more. Here is how that turned out:
The Edge alignment bar is very accurate. We validated it on another lathe after sweeping the tailstock with an indicator in the chuck.
I don't know if any of this will make my LRBR rifles shoot any better, or if my tenons or chambers will be any better. However, this is as good as I can get my lathe I think.
