I'm completely new to using a lathe and had some questions from some things I observed when trying to co-axially align a barrel.
I'm using a Viper truing jig and an unchambered .264 dia barrel. I roughed the barrel into the jig using a PTG range rod and .001" accuracy dial indicators.
1. Once I roughed in the rod and switched over to a test indicator with .0001" accuracy, I was able to adjust the barrel so that I could traverse the length of the rod with zero deflection. However, when I rotated the lathe, I showed deflection at the barrel end and the end of the range rod. When I adjusted the barrel so that I had alignment at the barrel (except as noted below in item 2) and alignment at the end of the range rod, I showed .0002 - 0003" of displacement when I traverse the length of the rod. Is this normal?
2. I think my range rod has a flat spot. When I was adjusting the barrel end of the range rod, I consistently showed a low spot at one point on the rod as I rotated it. I marked the low spot on the rod and then using the jaws as a reference point, I found that as I rotated the chuck 3 out of 4 of the jaws showed zero deflection to each other, but when I rotated to the jaw that I aligned with the mark on the range rod, I had about .0004" low point. I then removed the rod and aligned it with a different jaw on the chuck. Rotated the chuck and found the low point moved with the rod. I interpret these results as being a flat spot in the rod vs an alignment issue with the barrel. Is this a good assumption?
Thanks in advance.
I'm using a Viper truing jig and an unchambered .264 dia barrel. I roughed the barrel into the jig using a PTG range rod and .001" accuracy dial indicators.
1. Once I roughed in the rod and switched over to a test indicator with .0001" accuracy, I was able to adjust the barrel so that I could traverse the length of the rod with zero deflection. However, when I rotated the lathe, I showed deflection at the barrel end and the end of the range rod. When I adjusted the barrel so that I had alignment at the barrel (except as noted below in item 2) and alignment at the end of the range rod, I showed .0002 - 0003" of displacement when I traverse the length of the rod. Is this normal?
2. I think my range rod has a flat spot. When I was adjusting the barrel end of the range rod, I consistently showed a low spot at one point on the rod as I rotated it. I marked the low spot on the rod and then using the jaws as a reference point, I found that as I rotated the chuck 3 out of 4 of the jaws showed zero deflection to each other, but when I rotated to the jaw that I aligned with the mark on the range rod, I had about .0004" low point. I then removed the rod and aligned it with a different jaw on the chuck. Rotated the chuck and found the low point moved with the rod. I interpret these results as being a flat spot in the rod vs an alignment issue with the barrel. Is this a good assumption?
Thanks in advance.