Broach roughness - Was: Repinning flanges

[John Ross]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
Hi Don,
Would you enlighten us, on the method used to make the roughness on the broaches?
Thank you.
Regards,
John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
  ----- Original Message ----- 
  From: Donald Mannino 
  To: Pianotech 
  Sent: Friday, April 11, 2003 3:29 PM
  Subject: Re: Broach roughness - Was: Repinning flanges


  Clyde,

  You are right - the old APSCO broaches were really nasty, with the rough area knurled and much too agressive.  Hopefully Schaff threw them all out when theybought APSCO, but I don't realyl know.  The rough area is supposed to be subtly rough, with something like the grit of fine sandpaper, maybe 320 grit or finer.  The point is that the felt should not be chewed up when reaming, and the reaming area should not be larger than the smooth area, or the smooth area would not do a good job of burnishing the cloth.

  If the broach gets clogged up, the cloth has very likely been lubricated with something that has become gummy.  I run into this sometimes, and it immediately throws up a red flag.  If the cloth is gummy and sticky, there's a very good chance that reaming and repinning is not going to be a permanent solution.  The gumminess will rear it's ugly head again, and the action will go sluggish.  In this case you might consider cleaning all the bushings with naptha, then keeping a cloth nearby to clean the broach occasionally.

  With clean dry bushing cloth, a quick tap on the edge of the workbench is all that is needed to shake out any wool dust that has accumulated on the broach.  I have had broach sets that were used to do many, many sets of action parts that kept working like new.

  Don Mannino

  At 06:45 AM 4/11/2003 -0400, you wrote:

    Friends,

    I discovered quite by accident at a PTG convention, when looking over tools,
    that the rough part of broaches can be quite different.  I have used the same
    set for years, and the rough part is not rough enough to "clog up."  They
    always worked fine for me.

    But I came across a set that was so rough that it looked to me like they stood
    a good chance of removing too much felt.  I would be afraid to use them unless
    someone else looked at them and said, "Oh, yes, that's the way my set is, and
    they work fine."  I'm not going to buy such a set just to try it out.

    Regards,
    Clyde

    David Love wrote:

    > In the process of repinning the action using broaches, I found that the
    > roughened part of the broach kept clogging with felt which reduced it's
    > cutting efficiency.

    _______________________________________________
    pianotech list info: https://www.moypiano.com/resources/#archives 

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/2b/46/80/2f/attachment.htm

---------------------- multipart/alternative attachment--