fine grit hammer filing; Dremel tool

[Dave Nereson]

----- Original Message ----- 
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Sunday, November 14, 2004 6:19 AM
Subject: Re: fine grit hammer filing


> Have you ever tried the hammer-routing/shaping attachement for the Dremel
> tool? Once you get the hang of it you can reshape a set of total trash
> upright hammers in ten minutes or so. No need to even do any manual
> filing/sanding afterwards. I wouldn't battle an old upright without it!
>
> Terry Farrell

    Yes, I tried it a long time ago and couldn't figure it out.  Tried it
again a few months ago and decided it's just not worth it.  If you're
right-handed, you can do maybe half the bass section before your wrist runs
into the 2nd action bracket.  But at least in the bass, the hammers are
angled and you can get the tool perpendicular to the hammer.  But to do the
second half of the bass section, even if you do it left-handed, the angle of
the hammers forces the body of the Dremel tool into the dampers or other
hammers.
    Same problem in the treble, but the angle is the opposite direction.  If
you hold it with your right hand, the body of the tool is forced into the
dampers.  If you hold it with your left, the action bracket's in the way.
If the tenor hammers aren't angled ("straight bore"), you can do the first
half of the tenor section, then you run into the 3rd action bracket with the
tool and your right wrist.  I'm just not dextrous enough with my left hand
to switch.
    But the main problem is that that guide just isn't all that great.  With
it or without it, it's just too easy to dig a divot into the hammer.  All it
has to do is "catch" once, and, whiizzjhoop!, there went a big chunk of
hammer.  Now ya gotta cut an equal-sized piece of felt out of a scrap hammer
and glue it in.  Just kidding.
    Now on a grand it's a lot easier, but even there, I just can't tell if 
I'm removing one layer or ten with
the Dremel sander drum.
    --David Nereson, RPT