Teflon thingees help

[David ilvedson]

As I recall clicking problems were often caused by the factory 
reaming one side of a bushing, i.e. pushing the pin out enough 
to ream the empty side then pushing the pin back in.  The 
swing or gram test was fine because one side was too loose 
and the other tight=click down the road.  I have used Don's 
reamers with some success but teflon is slow to react 
compared to cloth.  I believe you are suppose to roll center 
pins between files and put them in pin vises?  Here in 
California teflon seems to hold up fairly well.  

David Ilvedson

Date sent:      	Sun, 07 Mar 1999 20:10:55 -0500
To:             	pianotech@ptg.org
From:           	Ken Jankura <kenrpt@mail.cvn.net>
Subject:        	Re: Teflon thingees help
Send reply to:  	pianotech@ptg.org

> At 06:03 PM 3/7/99 EST, you wrote:
> >Del,
> >
> >I defer to your experience on the durability of the teflon bushings.  I am
> >sure you have serviced many more than I have.  Maybe you are right;  the
> >problem was not the expansion and contraction of the wood around the
> bushings,
> >but instead it was the result of improper reaming and fitting techniques.  Do
> >you have anything to add to the Steinway bulletin regarding servicing teflon
> >bushings?    There are still quite a number of teflon actions in service.
> >Would you mind being more specific about the various techniques - types of
> >reamers, the acceptability (or not) of the centerpin rolled in a file, etc?
> >
> >I am interested in the comments of others who have serviced a considerable
> >number of these actions also - do you mind speaking up here?   Thanks - 
> > 
> >Bill Shull
> >U of Redlands, La Sierra University
> Dear List,
>     I am showing my ignorance here, but I'm bored with just showing it to a
> small circle of friends, so why not an international list of my peers, but
> where can I find basic info about teflon stuff (my journals only go back to
> '91) The general reaction I get from other techs is "replace it". Is there
> a a section in the S$S service manual that covers this? I have the
> misfortune of having a large percentage of the S$S that I service of the
> teflon persuasion. The killer is a local music school with about 10 turn of
> the century S$S that were re'actioned' in the 60's (need I add that there
> is no money to replace parts).
>    Does the Don Mannino broach type reamer system work? If they seem a
> little sluggish, should I presume that the pin is bent a little and
> replace? Or just that it is winter and they will get looser come summer?
> I've done a few and found that a little reaming goes a long way, that is ,
> a couple of swipes goes from 2-1/2 swings to 10 swings. I'd rather have
> them a little loose than effect touchweight so much, or should I say
> toughweight.
>    Newton says he has used regular pins, any other input on this? I've
> tried gently deforming (enlarging) the hole by rotating a pin off-axis on a
> couple. Is this OK? Will it be way too loose in the Summer? Should I just
> tell my clients to expect a touch of tendonitus in the winter :-) I've done
> the hole-in -wood-test-then-measure-it-under-different-humidity-conditions
> (the hole acts like wood would). My take has been that felt and wood have
> this symbiotic relationship thru the seasons, when the hole shrinks in dry
> weather, so does the felt, when the hole gets larger in humid weather, the
> felt takes on moisture, and in both extremes the friction changes less than
> you would expect. This teflon inert thing has me wondering whether I can
> accurately predict what is going to happen next season.
>    Has this been covered ad nauseum in the past, I'll gladly search the
> archives. Thanks.
> Ken Jankura, RPT
> Newburg, PA
>  
>  
> 


David Ilvedson, RPT
Pacifica, CA
ilvey@jps.net