Thanks Bill, I will look into that. My thoughts were different in what you said, I always thought doing the barrels horizontally with only one end firm, the weight of the barrels would deflect the bar no matter how careful you were, but reading your post clarifies that.
Off the top of you head, do you know what the diameter of the bar is, and how long is it?
Gnomon, I didn't see your last post as I was typing this one.
I looked in Grangers on-line, didn't see anything worth while, some of the brass and copper tubes had thicknesses with +/- .002. I found a piece of 3/4" copper tubing, I measured the thickness with a dial vernier caliper and it was also +/-.002 on both ends all the wall around. Before I cut a piece off, I laid a 24" straight edge along the length and it looked good. I cut a piece 31" long, cleaned the burrs on the O.D. and I.D. and placed it on the rod.
With the end butted up against the stop on the left, it read .040-.043, which I knew was too much. Read in increments of 4" turning tube to read all the way around, it was reading .032-.033 which is what I got on the vernier. Half way down it read .022-.017 and near the end on the right side read .032-.034. The inconsistant reading in the center tells me that the tubing could have a wow in it and it also was not near concentric. Thinking now, it doesn't sound like a wow, because I should have had a greater reading 180 degrees from the lowest reading. Don't know.
I think I definitly need to get another rod and have the balls drilled on a milling machine where I can have them perfectly inline with each other and also control the depth much easier.
I have nothing but time.
Last edited by JDW; 01/20/12 08:29 PM.
