[CAUT] Checking

[Jim Busby]

Jurgen,

 

This is a 1967 M.

 

JB

 

________________________________

From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
Jim Busby
Sent: Thursday, December 21, 2006 12:22 PM
To: College and University Technicians
Subject: Re: [CAUT] Checking

 

Jurgen,

 

I just checked an M and the distance is about an inch less, but there is
a 3/16 increase from bass to treble. I'll check some others. I'd like to
know why too.

 

Jim

 

________________________________

From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
Jurgen Goering
Sent: Thursday, December 21, 2006 12:04 PM
To: caut at ptg.org
Subject: Re: [CAUT] Checking

 

Yes, Thanks Alan for the S&S backcheck info. 

 

One question: Given an assumed constant tail length and bore length
(within bass and treble) I don't quite understand why the backcheck
height "increases linearly (with respect to note number) from 3 3/8" for
note # 1 to 3 9/16" for note # 88". 

 

Can someone clarify this? 

Also, would these dimensions be the same in all models? 

 

Jurgen Goering 

Piano Forte Supply 

(250) 754-2440 

info at pianofortesupply.com 

http://www.pianofortesupply.com 

	 

	Alan, 

	Thanks for the copy of the instructions. 

	 

	The first time I heard of raising the backchecks was from Scott
Jones 

	teaching at a regional seminar. I think he also talked about
using a snap 

	ring pliers. Kevin Stock, also with S&S for a time, had a
modified snap 

	ring pliers with a slot cut out for the wire. He would just lift
them, then 

	even them out. I think that's because he knew what he was doing 

	intuitively. It was Roger Jolly that I first heard put some
numbers which I 

	need with the idea;.... tail arc radius at 1/2 the hammer
hanging distance 

	(usually right around 2 1/2), shank intersecting roughly the top
1/3 of the 

	backcheck (this does not need to be fussed with if the hammer
line gets 

	raised from filing or whatever), and the backcheck angled back
18 degress 

	from vertical (pretty similar to the 68 or 70 degrees you work
from, just 

	different point of reference and 4 deg. different). I always
enjoy hearing 

	the different approaches to the same thing, because not all
things work the 

	same for everyone, (not wrong, just different) and it is also
good to get 

	something reaffirmed by a seperate source. A different
perspective can 

	turn the light bulb on. 

	 

	Tim G 

		 

		Attached is a S&S document about installing backchecks. 

		 

		Have a great break! 

		 

		Alan 

		 

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