Re: [Harp-L] chamfering and tip scooping (was Seydel 1847 overblow friendly

["Ludo Beckers" <lazylew@xxxxxxxxx>]

 <http://groups.yahoo.com/group/harp-l-archives/message/55442;_ylc=X3oDMTJyOWlqOWVrBF9TAzk3MzU5NzE1BGdycElkAzQ1NjMzOTIEZ3Jwc3BJZAMxNzA1MDMyMTk1BG1zZ0lkAzU1NDQyBHNlYwNkbXNnBHNsawN2bXNnBHN0aW1lAzExODYxNDQ0MTY->
Hi
Ron

I do it the way it's shown on the picture here, chamfering in the corners of
the slot:
http://www.overblow.com/?menuid=161

At first I used this method:
http://www.fractal.art.br/ecafhb/en/scooping.html
using a tiny drill and indeed on both sides.

Advice from Pat Missin was that, if the purpose is to have easier OB's, the
rivet side of the plate should be worked on only.
Apart from making the reed move in a more stable way (avoiding squeeks) it
also mellows the sound after embossing.
Tinus advized the two corners method, which supposedly is better for the
stabilty of the lateral reed movement (which is the cause of possible
squeeks).

<<Ludo or anybody, can you describe what is the result between a stock harp
and after it has be chamfered to round off the corners of the slot?

No I can't, since I always emboss and gap first - the harp is not stock then
anymore.
But it's obvious that you can narrow the gap further.

<<Can u remove too much metal and have a negative effect?

I guess so, but I have no experience there.

<<How does one know when the optimal amount of metal has been removed?

Trial and error - my experience is that just a few gentle strokes with the
needle file suffice.
When I hold the harp to the light it is just visible that some material has
been removed; less than a millimeter I'd say.

<<Fwiw, someone said Pat Missin described tip scooping as a procedure done
to
the underside, not the rivet side of the reed plate. From what we've been
reading and seeing, this doesn't seem to be correct.

AFAIK it is. The terminology comes from the world of accordeon repairers.
Just like the somewhat unfortunate term "overblowing" is standard these
days, most people call chamfering tip scooping erroneously.

<<Does anybody alter the reedplate from underneath?

On accordeons I believe.
Let me stress the fact that I'm NOT a pro-customizer at all.
There are many people on this list who could probably give better indepth
insights on all of this.
Also, when talking to Joe Filisko about it, he said he doesn't do any
chamfering (or tip scooping).
BTW I'm off to buy a glasscutter now, so I can try out Rupert's embossing
method at the slot end, and your tips :-)

Ludo