by TerryMcGee on Wed Mar 13, 2013 10:14 pm
I don't think really precise measurements would be necessary, as long as we were able to provide some idea of distance up or down. You would probably like to get the clapper back to the same location though! Do you happen to know what the thread on the clapper shaft is? (EG 3/4" UNC). If you put a mark on the nuts and the clapper, and wound the top nut up say 10 full turns, then lift the clapper and wind the bottom nut up 10 turns, we could calculate what that is in height. Or perhaps you could use a rule from the bottom of the clapper shaft, or from a mark on the shaft. Relative measurements (eg 1/2" higher and lower) are enough, we don't need absolute measurements.
One issue that might cloud results is that the small flat that probably has already formed on the clapper may not sit well on the bell in the new locations. To be really fair, we should first rotate the clapper a bit to present a fresh face. Do all your testing at that setting, then afterwards, return the clapper to the original position so it blends best with its neighbours.
This is an example of what I said before - you tend to find out during the job how you should have done it! So it does pay to think ahead as far as you can.
Terry