There is tried and tested key position calculator at http://www.hurdygurdy.org Just click on "Resources" on the home page It gives you the exact key positions for a 345mm sounding length It gives both Equal and Just temperament values for 2 octaves If you download the Excel sheet you can enter any string length Chris Allen uses these numbers for all his HGs In fact I believe he sets his keys midway between the 2 temps This means that both Just or Equal can be set with minimal tangent angles
Graham Whyte -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: 07 March 2007 23:55 To: [email protected] Subject: Re: [HG] Shaft and wheel relationship > I was going to use the Lambert plans for the body style , but incorporate the > plans from the Dewit book for all the lengths and key placements. And boy do > those plans make this insturment look tiny... Seth You may benefit from doing the math yourself for key placement - I don't recall how accurate they were. The math for each tangent placement can be worked out from first principles starting with the 12th root of 2 (because it takes twelve divisions to get to half of the string length at the 12th tangent or fret) - or you can look around online for a fret position calculator, of which there are many for aspiring guitar-builders. A typical chanter string sounding length is 344 mm. After that it's a matter of deciding where the wheel should go and how wide it should be, and doing the requisite math to get the wheel angle right so that the ears don't stick 'way out and make your gurdy look like H. Ross Perot. That's where things get REALLY interesting. There's a thought - a gurdy with the peghead carved with the likeness of H. Ross. OK, let's not go there. Alden
