Hurdy gurdy tangent spacing

[Barry Black]

I am planning to build another hg now that my Pimpard is in the hands of my musician son and apparently not a complete failure and waste of pretty wood.

This time I am going to make a copy of a Varquain guitar shaped one with a few modifications. I know nothing about music and so before I begin, I would like to better understand the spacing of tangents. My question is, is the overall string length from bridge to nut and then the tangent spacing a mathematical arrangement, or just something that has evolved to sound 'right' ?

I know so little that I am not sure that my question makes sense, but any help in ths matter would be appreciated.

[John Dallas]

Yes, it is a mathematical arrangement.
Basically, the tangents must be arranged like the frets on a guitar or similar instrument. That is, the first fret/tangent is set at a certain fraction of the distance from nut to bridge; the second fret/tangent is set at the same fraction of the distance between the first fret and the bridge, and so on. Any luthier will tell you what that fraction is. I believe luthiers' suppliers offer templates that allow you to mark off the correct fret (or in your case tangent) spacings for a given string length.

Of course, the frets/tangents get closer together the nearer you get to the bridge. From the little I know of hurdy-gurdies and nyckelharpas, part of the design process is to make the spacing between the "buttons" (where you put your fingers) more regular than that between the tangents themselves.

Hope this helps,
Cheers,
John

[Barry Black]

Thanks John. Now I just need to find out what that 'fraction' is. I guess I could find a guitar, measure the distance from nut to the closest fret and calculate the fraction myself.

[John Dallas]

Hi, Barry,

Before you go borrowing a guitar, try an online fret calculator here:https://www.stewmac.com/FretCalculator or here: http://www.harpkit.com/category/fretcalc.html.

Note that they give the absolute distance from the nut to each fret - not the ratio from one fret to the next, which would propagate any error in calculation or measurement.

Just copying the spacing from an existing instrument is not a bad idea. My first luthiery project was a langeleik, a Norwegian fretted zither, and I copied the fret spacings from my banjo. I just laid my blank fretboard alongside the banjo's, and marked off the fret and bridge positions. The important thing is to decide what fret on the existing instrument to start with. It worked for me!

Cheers,
John

[Barry Black]

Thanks, the fret calculator is a big help.

[Yuri Terenyi]

Barry, the tangents on all functional hurdy-gurdies are movable. There are more than one way of achieving it, the traditional ones look like flattish flags, pivoting on thin dowel-like protrusions. This is very important. Fixed frets are a pain, and it's impossible that they will be truly in tune. Also, to be even more complicated, there are more than one tuning systems, and depending on what music is going to be played, the tangents can be tuned in Pythagorean, Meantone or one of later Baroque tuning systems. But never in equal temperament, gurdies in Equal t. sound er, not very good. The same instrument can be retuned (that is, the flags , not the strings) for playing French Baroque music one day, and Medieval the other.

[Barry Black]

On my Pimpard hg I made the tangents from hard maple and attached them to the key bars with 2 X 56 pan headed machine screws which allowed them to be adjusted quite easily. I think for the sake of practicality I'll do the same thing on the Varquain.
I want it to have a period look however I do also want it to be functional. The Pimpard plans that I have showed veery clearly the layout and spacing of the tangents.
The Varquain drawing is not as clear so I asked for help with the spacing just to clarify what the drawing was showing.
My son plans to use the hg in his Viking metal band so goodness knows what tuning he will end up with.

[Clay Schaeffer]

For spacing frets on a guitar in equal temperament you use the twelveth root of two, or working backwards divide the scale length by 17.817, subtract that value from the scale length to get the first fret position, take the remaining scale length, divide it by 17.817, subtract that value from the remaining scale scale length, and continue in this fashion until you have calculated as many frets as desired.
For a hurdy gurdy having movable tangents is certainly a good idea for the reasons stated above. Movable frets were tried on guitars but proved cunbersome and unworkable for the most part ( Panormo and Thompson "Enharmonic guitar").