Adapting Waverly Tuners

Frank Ford -

The patient is a venerable 1932 Martin OM-28  -  a guitar that has been known for decades as a holy grail of fingerstyle guitars. Unfortunately, the original Grover tuners used on this model were made with a "double lead" worm gear which resulted in a 6:1 gear ratio.  As these tuners wear, they tend to loosen to the point that they really don't hold the tension of steel strings adequately.  For an active player, these 6:1 tuners are quite a burden, so we often replace them with modern, higher ratio, better quality tuners.

In recent years, some of the best replica vintage style tuners have been made by Stewart MacDonald under the Waverly trademark.   Accurately styled to look like the prewar Grover tuners used on many vintage guitars, these tuners have gained favor among musicians the world over.  But, the mounting plate doesn't match up with the very early 6:1 design (on the left in the photo above), and the screw holes are located such that  they might require drilling new screw holes in the peghead of a valuable collectible guitar.   Rather than filling and drilling holes in the instrument, I'd much rather modify the replacement tuners.  Whenever possible I like to adhere to the "principle of reversibility," allowing for a return to the original state in the future should it be desirable to do so.

In this case, I think the easiest and most reasonable approach is to enlarge the holes in the tuner plates so they can be mounted and removed easily with no damage to the guitar.  Mounting the new tuners in this manner will make it possible to reinstall the original tuners with no sign that the instrument ever had the tuners changed to modern ones.


I do this job often enough that I modified the jaws of my milling machine vise to hold the tuners safely and rigidly:



Then, it's a quick bit of milling on each hole, enlarging it to a slot that will allow the tuner to be screwed in place without relocating holes in the guitar peghead.  Lowering the mill ing cutter into the mounting screw hole, I can advance the work into the cutter to elongate it:


Years ago, I often did this same job with a tiny needle file.  The milling machine makes it go a bit more neatly, and a lot more quickly.

Here, you can see the tuner in place, revealing the original holes through thee longated slots:



Once they are screwed down, the tuners look pretty good on this old timer.   I used the Waverly model 4076 with the optional "aged" nickel finish so the hardware would not stand out too much on a guitar that was made a dozen years before I was born:


Even the tiny mounting screws have a nice aged patina.