Acoustic bridge string slots. The bridges on most flattops don’t have their string slots cut at the correct angle. As a result, the strings make a sharp bend between the pin hole and the saddle, and this can create tuning issues and string breakage. Cutting or resizing string slots in the bridge will reduce these problems. The objective is to create a small, angled channel so the string follows a gentle curve from the pin hole up to the bridge saddle.
Start by fitting your Dremel with a Flex-Shaft attachment and a 1/16" cutting bit. Then remove the strings and bridge saddle. Next, carefully cut angled slots at the saddle-side edge of the pin hole by rolling the bit in the hole (Photo 6). It only takes one or two “swipes” to get it right. Avoid cutting the slots too deep—this can cause future problems with the bridge. Use a moderate speed while applying steady, gentle pressure.
Smoothing sharp edges on an acoustic saddle. It can be distracting or even painful if your picking hand hits the sharp edge of the bridge saddle on a flattop. Here’s an easy fix.
Note: Before you go any further, determine the saddle material. A Dremel spins from 5,000 to 30,000 rpm, and while that’s fine for bone, it can produce more than enough friction to melt synthetic materials. If you have a plastic, Micarta, or Tusq saddle, I recommend sanding or filing it by hand. However, if you’re just itching to do this with your Dremel, use the lowest speed to prevent a meltdown.
Remove the strings, pull out the saddle, and place it in a vice. Next, attach a small grinding stone to your Dremel. Set it to a medium speed and use the small stone to gently grind the edge to a rounded shape (Photo 7). Take your time and be patient.
Do not attempt this with the saddle still in the guitar’s bridge. The tool is spinning at about 15,000 rpm, and if you slip, you can permanently damage the bridge or soundboard.Once you’ve done several of these projects, you’re likely to find other ways to put a Dremel tool to work on your instruments. Keep it handy and be creative!