Mechanics

TUNING MACHINES

Tuning Machines

In the beginning I used guitar and bass tuning machines, scavenging them of old guitars or buying cheap ones. When I began to build a twenty-five string dulcimer I realized I needed to make my own. Four-plus sets of tuning machines were more than I wanted to buy and as I was planning to use music wire for the strings, they most likely would have broken anyway. The big dulcimer never worked (the tension required to tune it bent a very beefy frame –one that would have supported a mid-duty trailer), but it taught me a few lessons, one of which was how to make tuning heads (another was why so many traditional instruments are tuned by moving the bridges).

I drill a 1/8 hole in the shaft of a 3/8 bolt. I tap the pinblock or headstock or whatever you want to call it to receive the bolt and use a locknut of some sort to hold it when tuned. It takes two wrenches to tune a string, but it isn’t as bad as I’d have thought. Recently I discovered belleville disc spring washers which I use under the pinblock.  This has made the tuning process way less grief-intensive.  Using fine thread bolts might be better, but the coarse ones were cheap and I had a box of them. I used 3/8 because they were easier to drill than 1/4 would be and (on the dulcimer) I was planning to use .125 music wire for the low strings (didn't work) and I wanted as much strength as I could get.   Mostly now I use 1/4" bolts for the pegs as it saves a lot of space.

At the tail end I use a 1/4 bolt as a pin and there is some fine tuning available from it.