Better Bolt Bridges – Left-handed Thread Rod
I had been struggling with keeping my floating bolt bridges in place for proper intonation. I would set the bridge perfectly, as pictured below:
However, over time, the vibration of the strings would eventually turn the bolt, thus throwing my guitar out of tune, as pictured below:
If you look at the first picture, you can see that the orientation of the string is strained as it fights to stay in one of the thread slots. The force that the string places on the bolt naturally moves the bolt into a position where the string sits comfortably within a thread slot.
Even bolt bridges that are mounted into a slot suffer difficulties. However, since the bolt can not turn to orientate the threads with the strings, they are more prone to slipping into another thread slot, which leads to intonation and string spacing problems. Plus, a string sitting on top of threads allows less usable surface area than a string seated within a thread slot.
The solution showed up on my doorstep yesterday morning. I had been trying the figure this out when I recalled that, in my warehouse days, contractors would request left-handed thread rod for certain jobs. I looked around and found 3/8 left-handed steel rod at Fastenal for $26.87, plus shipping, which seems pricey, but I can cut about 36 2″ floating/fixed bridges for $1.08 each.
This is the direct link to the rod that I purchased: https://www.fastenal.com/products/details/47304
Here is the result. As you can see in the image below, the floating bolt bridge is once again in tune; however, this time the strings will not cause the bolt to turn because the strings are now seated comfortably within the thread slots.
Tragedy averted—now I just have to find some left-handed brass rod.