A few years ago I came across an article in
French titled 'Functionnement du chevalet mobile
de la vielle à roue' by Pierre Rebaud, originally
published in 1984,which shows the various forces
on the chien which cause it to work. The article
says that the up and down movement of the chien
repeats 'approxiamately 293' times a second. I
can only find hard-copy at the moment, but will
scan it in and post the article on the UK hurdy-gurdy site.
Dave
At 21:04 06/01/2008, you wrote:
Also, the bridge doesn't move that much (you
can't really see it move), only a tiny amount
but very fast (hence the buzz rather than a
thump). I had to prove it to myself that it
really was moving by placing a finger on it (the
buzz stops) and removing my finger (it started
again) when I got my HG. Maybe "vibrates in a
vertical plane", although strictly inaccurate,
may give a better mental picture of the process
repeated many times a second (as had been said,
it doesn't actually vibrate but lifts up and taps back down).
Anyone actually been able to measure how much it lifts on average?
Colin Hill
----- Original Message ----- From: "Tony Vincent" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, January 06, 2008 8:27 PM
Subject: Re: [HG] "a Newbie question"
At 11:06 AM 1/6/2008 -0800, you wrote:
So if the dog moves up and down the string, won't that eventually
break the string, in the contact area where it rubs?
Hi Geoffrey,
The string dosn't move in the dog.
Imagine an ordinary bridge, if you lift one end
and let it go string tension will snap it back down
and it will make a noise.
The dog, (the bridge) is balanced just below the point of lifting.
The string pressure on the turning wheel, in combination
with the sticky rosin is enought to tip the balance and
lift the foot of the dog off the face of the instrument,
the tension on the string is increased to the point where
the wheel and sticky rosin can't hold it anymore and it
snaps back down with a little tap. It happens so fast that
it produces a buzz. The tuner in the tail piece is attached
to a piece of thread that is linked to the string and when
turned will increase the pressure of the string on the wheel
amking it more or less sensitive.
If you think is complex to explain try making one!
Regards, Tony
