odd agraffes

[William Monroe]

Hi Folks,

I've got an old M&H grand and the agraffe stems are (as close as I can tell) 7mm x 0.75.  The stems actually mic out closer to 9/32" diameter, but the threads are dead on with a metric thread count gauge at 0.75 so I'm guessing metric dia. as well.

Actual measurement is .280" or 7.1mm

I was hoping to replace these with new but have been unable to find anything available.  And because they are larger in diameter than anything else available, the option of drilling out and re-tapping for a common size is unavailable unless I were to fill first.  I'm unfamiliar with that process so haven't given it serious consideration yet.  Any suggestions for a source of new ones or does anyone have some extra used ones in case of breakage?

The old ones came out fine and I'll plan on re-installing them, but I'm always nervous about using the old agraffes again, especially after extraction/re-installation.  One never knows what the structural integrity of these will be in the long term.  I'm at least happy that because the diameter is larger than anything commonly produced today it will add (at least in some small way) a little more strength in the stem.  

 

William R. Monroe
www.a440piano.net

[Ron Nossaman]

> www.a440piano.net <http://www.a440piano.net>
>


Here is where someone always suggests Helicoil, but they won't work on
any agraffe and particularly not on these.

They're 9/32-32. Joel Rappaport told me many years ago that he was
having some made, but I haven't heard a word since. I'd buy Pianotech's
inserts, and use standard agraffes. The stem of modern 1/4" agraffes is
nearly unbreakable. The ONLY reason we have broken agraffes in the old
Steinways is because the stems weren't threaded all the way, and the
agraffe never seated properly.
Ron N

[Dale Fox]

https://www.pianoteksupply.com/product/484/Universal-Agraffe-Inserts-100.aspx

Bill,   this is a link to PianoTek's agraffe inserts.  They also sell the appropriate tap for the inserts.  I have done this on several M&Hs that were getting complete remanufacuring.  The hardest thing to do is to get the angle correct when drilling before tapping,which is not all that hard as you can insert a dowel or drill bit in an adjoining, as of yet, not drilled hole, for an angle target.  Agraffe holes are rarely plumb.

Ron, I have replaced 4 broken ones in Steinways in the past 6 months.  All were 7/32. None were threaded to the top. 

Dale Fox

> Subject: Re: [pianotech] odd agraffes
> To: pian...@googlegroups.com
> From: rnos...@cox.net
> Date: Fri, 29 Jan 2016 10:46:04 -0600

[Joseph Garrett]

Dale,

I'd suggest a drill press approach rather than drilling free hand. For me I use the same fixture that I use for drilling pinblocks in the piano. That way you get better angle consistency.

Best,

Joe

Captain of the Tool Police
Squares R I
gpianoworks.com

[Ron Nossaman]

On 1/29/2016 11:18 AM, Dale Fox wrote:
>
> Ron, I have replaced 4 broken ones in Steinways in the past 6 months.
> All were 7/32. None were threaded to the top.

Yep, that's the only reason they break.
Ron N

[Mike Spalding]

Hi William,

Been there.  1926 M&H A, agraffe broke when I reinstalled it, destroying my confidence in all the old agraffes.  I couldn't find replacements with the same thread.  Ended up using Pianotek "universal agraffe inserts" http://www.pianoteksupply.com/product/484/Universal-Agraffe-Inserts-100.aspx  The most difficult part of the process was drilling out the plate  - it's hard to keep the drill aligned with the original hole.  If there is a next time, I will a) do the drilling before refinishing the plate, and b) drill in several stages with small increases in drill size.

Good luck, and if you find a better solution, let us know.

Mike

On 1/29/2016 10:22 AM, William Monroe wrote:

[Ron Nossaman]

On 1/29/2016 11:43 AM, Mike Spalding wrote:
>

> The most difficult part of the process was drilling out the plate - it's
> hard to keep the drill aligned with the original hole. If there is a
> next time, I will a) do the drilling before refinishing the plate, and
> b) drill in several stages with small increases in drill size.

I think I'd be tempted to do some careful grinding on a 21/64" bit to
make a pilot to align to and follow the original hole. It could be
cleanly drilled in one pass that way.
Ron N

[Terry Farrell]

Ron - can you expand on your suggestion of grinding a bit into a pilot point? I have to admit that my machinist expertise is wanting at best. Wouldn’t your basic straight angled bit tip follow a hole very well? Are you suggesting to make a pilot tip that just fits into the original threaded hole? I can image if one were to do that then indeed it would follow the original hole perfectly.

I love drilling cast iron - I find it very satisfying!

Terry Farrell

[Ron Nossaman]

On 1/29/2016 3:24 PM, Terry Farrell wrote:
> Ron - can you expand on your suggestion of grinding a bit into a
> pilot point? I have to admit that my machinist expertise is wanting
> at best. Wouldn’t your basic straight angled bit tip follow a hole
> very well?

It depends on the relative size of the pilot hole to the finished size.
This would be about 0.060" or so different. It seemed to me that might
be enough to make it touchy. Maybe not, without trying it.

> Are you suggesting to make a pilot tip that just fits into
> the original threaded hole? I can image if one were to do that then
> indeed it would follow the original hole perfectly.

Yes. I'd use a slightly smaller bit than the Q pilot for the tap,
assuming my grind wouldn't be exactly concentric.

> I love drilling cast iron - I find it very satisfying!

As long as you steepen the cutting angle a bit so it doesn't grab and
auger in, yes. It's nice stuff to drill - until you hit sand pockets and
those really hard spots. Then there's getting rid of all the graphite
and toxic dust. My perpetual sinus curse sure doesn't like it, and Loui
isn't real pleased with the black footprints in the house either.
Ron N

[Ron Nossaman]

On 1/29/2016 10:46 AM, Ron Nossaman wrote:

> They're 9/32-32.

Sorry, I just remembered that I misremembered, remember? They're
9/32-34. Odd that I'd forget something that critical, but there you go.
Ron N

[Joseph Garrett]

Ron,
Would that be one of those thread sizes that used be around before WWII?
Best,
Joe

Captain of the Tool Police
Squares R I
gpianoworks.com

-----Original Message-----
>From: Ron Nossaman <rnos...@cox.net>
>Sent: Jan 29, 2016 6:44 PM
>To: pian...@googlegroups.com
>Subject: Re: [pianotech] odd agraffes
>

[Ron Nossaman]

On 1/29/2016 9:35 PM, Joseph Garrett wrote:
> Ron,
> Would that be one of those thread sizes that used be around before WWII?

Beats me. I'm a mechanic, not a historian. It doesn't seem to be
anything standard, including ME. Why M&H pulled such a thread out of
their repertoire, I have no idea. Seems counterproductive unless it was
advertised as a magic thread or some such. Why a non standard thread
that no one knows about? You tell me.
Ron N

[David Love]

Dale (or anyone else) if you have some spare MH agraffes I could use about a dozen for repairs.  I think it's best to just recondition them rather than go the insert route but that works too.  

thanks.  Contact me off list at this or davidlo...@comcast.net. 

[William Monroe]

Thanks everyone.  Out of town this weekend with the family so I haven't replied in a timely fashion.  I have some of these inserts and have used them a couple of times in the past but had always viewed them as a "last resort" type of repair for something that got really buggered up.  It's interesting to hear that some of you are (would) use them as a complete replacement alternative.  At any rate, I appreciate the input on methodology.

William R. Monroe
www.a440piano.net

[Ron Nossaman]

I can't speak for anyone else, but given the choice of recycling
unobtainable parts that leave the next guy with nowhere to go, and
converting to standard and universally available parts, I'll do the
conversion.
Ron N

[William Monroe]

Appreciate the perspective, Ron.  On the other hand, that next guy would still have the option of installing inserts, I suppose.  As I've mentioned before my preference is new (standard) parts here, I just hadn't thought of installing inserts as a wholesale process.  I consider myself broadened.

William R. Monroe

[Dale Fox]

I will look when I get back home.  In Virginia for a funeral

Sent from my iPad

[Isaac Sadigursky]

Hi, Bill !
 I had tried to call you...
 I have 1 doz of Single Hole 9/32" brand new ones and 14-Bi-chords
No Tri-chords...
If  you want me to tell you, how I got them..
 Well,don't even ask........
They are brand new ones.....Still shiny...
I wish, Schaff could help us by asking their machinist to make 9/32" agraffes available for Mason-Hamlin restorations...
Call me
818-991-3672
Isaac Sadigursky
 "Isaac's Underground Supply House".... [just kidding]

[Ron Nossaman]

On 2/2/2016 12:12 AM, Isaac Sadigursky wrote:
> Hi, Bill !
> I had tried to call you...
> I have 1 doz of Single Hole 9/32" brand new ones and 14-Bi-chords
> No Tri-chords...
> If you want me to tell you, how I got them..
> Well,don't even ask........
> They are brand new ones.....Still shiny...
> I wish, Schaff could help us by asking their machinist to make 9/32"
> agraffes available for Mason-Hamlin restorations...

Isaac,
If you got those agraffes from Schaff, they are the wrong thread.
Schaff's were 36tpi, and M&H are 34. As if that isn't enough, for 25
years that I know of, half of them were made with double helix threads.
When I informed them of that, their "machinist" checked them with a
thread gauge and proclaimed them to be fine. I never was able to
describe to them the difference between a single helix (which it of
course should have been) and a double helix (which fits NOTHING). I even
made a clamshell jig, tapped with the very tap they sell for these
agraffes, so they could see for themselves that it wouldn't work. I CAd
different color threads in each helix and sent them the whole mess. They
sent it all back. Never even looked at it, and still have no clue what
the fuss was about. I had bought a set of these things before inserts
were available, and I wasn't looking forward to either reusing the
originals, or making my own inserts, so this looked like a viable
option. After I found the double helix nonsense, I bought all of the
9/32 agraffes they had in stock to get them out of the loop. They had
been selling the things and having them returned for at least 25 years
without managing to figure out what the problem was, so I tried to end it.

Funny thing, I ran into the package yesterday, that I had sent to
Schaff. It only has one double helix agraffe in it, so I don't know what
I did with the rest.

Anyway, be careful what you wish for from Schaff.
Ron N

[Ron Nossaman]

On 1/29/2016 10:22 AM, William Monroe wrote:
> Hi Folks,
>
> I've got an old M&H grand and the agraffe stems are (as close as I can
> tell) 7mm x 0.75. The stems actually mic out closer to 9/32" diameter,
> but the threads are dead on with a metric thread count gauge at 0.75 so
> I'm guessing metric dia. as well.
>
> Actual measurement is .280" or 7.1mm

You're right. It seems it's likely M7x.75.
Ron N