Hi Seth,
You are right to be skeptical about holding a chisel in your hand:
that is a recipe for trouble. What you need is a flat cabinet scraper
that can take just a hair off the wheel at a time (some people use a
piece of glass that has a sharp edge, but the cabinet scraper is
probably easier to use and safer). You then need a guard to sit on
the soundboard (so you don't scrape the soundboard to pieces). This
can be a simple piece of thin, hard cardboard (not corrugated!)
shaped like a U that sits on the soundboard wrapped around the wheel.
Viewed from the crank end, it will sit on the right side of the
wheel. You then anchor the instrument firmly in place (while you can
do this in your lap, you are probably better off on your work bench).
The scraper sits on the guard on top of the soundboard and you then
turn the wheel towards you (the normal playing direction, but you are
on the opposite side from where you would normally be) so that it is
moving down toward where you will place the scraper. Gently bring the
scraper to the wheel, allowing it to lie flat on the guard you placed
on the soundboard (scrapers cut perpendicular to the body of the
scraper) until it is just taking off the very top of the highest
portion on the wheel (you'll know when you're doing it right because
you'll hear a ththth.....ththth.....ththth.....ththth sort of sound).
Take it slow and easy: you don't want the scraper to move with the
wheel, but rather to only take off material from the high points. As
you take more material off you'll find that the scraper is taking off
material from more and more of the wheel. You will have a true wheel
when you find that the scraper is taking material off from the entire
circumference of the wheel.
If this doesn't make sense, let me know and I will send you some
diagrams directly to your e-mail.
Best,
Arle
On Jan 2, 2007, at 4:12 PM, Seth Hamon wrote:
I'm currently building a symphony gurdy while I wait on my
Orca I order from hurdygurdy.com . I have Destrem and Heidemans
book which says to hold a sharp chisel in your left hand while
turning the wheel, but it's very hard to do this without the chisel
moving. The wheel is only a hair off but I don't want to mess it up
when I true it up... Does anyone have info on how this is done or
another way to true the wheel. It's off so very little that you
cannot see it with your eye but when the wheel passes over the
string you can feel a very slight loosening of the tension...
Thanks, Seth I'll put some pics in photobucket to show what I'm
making, lots of fun...
