HCH = Hammer Center Height
WCH = Wippen Center Height (WCH = (HCH - 64 mm))
String Height (SH) minus HCH = Hammer Bore (HB)
Now, if your hammer bore is shorter than needed and if you elevate the top action to the above equation, the rail may be too close to the block, the flange screws or upstop screws might hit the block. IOW, (SH - HB) might have one raising the HCH to the point where the screws above the hammer rail bind on the block.
The top action might be situated such that it would be better if it were moved left or right to align to the capstans and strings. Moving front-to-back could help with geometry or Strike Point, the key frame may need relocation.
Here's a run-down on what happened to an Asian grand: Measured C4
UW DW BW F SW FW SBR
a. 32 60 46 14 10.9 32 6.4 original survey
b. 26 52 39 13 9.9 32 6.3 reshape hammers/taper/re-arc tails; graduate set
c. 24 44 34 10 9.9 32 5.8 increase knuckle radius 1 mm to 18.5 mm
d. 22 38 30 8 9.9 32 5.4 relocate top action back 3 mm (better aligned Strike Point in bass, moved key frame more at treble end than bass end)
e. 30 46 38 8 9.9 24 5.4 alter FW to target 38 BW
Fortunately, I have not needed to go to this length on other actions. But I have done most to some actions.
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Regards,
Jon Page
mailto:
jonpage@comcast.nethttp://www.pianocapecod.com------------------------------
Original Message:
Sent: 11-22-2022 05:54
From: Terrence Farrell
Subject: Wurlitzer/Young Chang Grand Serial Number (Expanding Action Brackets)
Wow! Jon! You be throwing me for one giant loop!!! I always appreciate you sharing your wisdom and try to understand all of it. But I am lost here. What is WCH and HCH?
Hammer bore causing the unstop screws to bind on the stretcher or block? How would hammer bore affect that? There is plenty of clearance to get action out of cavity.
Top action location optimal? Are you referring to capstan/wippen heel relationship? Are you referring to how that might affect geometry?
Sorry for what I'm sure are very basic questions, but I'm just trying to fully understand all you are saying.....
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Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com
813-684-3505
Original Message:
Sent: 11-20-2022 15:39
From: Jon Page
Subject: Wurlitzer/Young Chang Grand Serial Number (Expanding Action Brackets)
There are two sizes on the rails. Shorter ones on the ends and the taller ones in the center. Replace the center ones first. You may have to redrill the screw holes on the key frame. But locating the center ones first will help to index the location of the hammer rail. The spread for that year would be 112.5 mm.
One way to tell who made these pianos is in the model number. Having a "G" would be Young Chang; a "C" would be Samick.
A way to remember is that there is a G in YC and a C in Samick. Yeah, they both have C's but only one has a G.
While you're at it. it is a good time to make the WCH 64 mm below the HCH. And the HCH = String height minus Hammer Bore. As long as the bore is not too short whichc cause the rep lever upstop screws to bind on the stretcher or bottom of the block. Also, is the top action location optimal, front-to-back?
You have one chance to 'make it right'.
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Regards,
Jon Page
mailto:jonpage@comcast.net
http://www.pianocapecod.com
Original Message:
Sent: 11-20-2022 14:53
From: Philip Bondi
Subject: Wurlitzer/Young Chang Grand Serial Number (Expanding Action Brackets)
Terry, that would be Supply 88, not Piano 88. Sheesh getting olde.
Supply88 - Innovative Tools & Supplies for Piano Technicians
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-Phil Bondi
Original Message:
Sent: 11-20-2022 11:17
From: Terrence Farrell
Subject: Wurlitzer/Young Chang Grand Serial Number (Expanding Action Brackets)
I have a new customer with a Wurlitzer fetal grand piano she purchased new in about 1991. The model is G-411 and the serial number is 2057284. My question is whether my Pierce Atlas would list the serial number under Wurlitzer or Young Chang. It seems pretty clear to me that it would be under Wurlitzer. The reason I need to be sure about that is to get the year of manufacture correct. I need the correct manufacture date because I need to order a set of replacement action brackets as the original brackets appear to be growing (action spread is 115mm and most of the hammers are blocking against the strings. My understanding is that the brackets had a design change about 1991 where the action spread changed from 112.5mm to 113.5mm (or the other way around).
FWIW, I described to her that the action may need to be re-regulated after the new brackets are installed because another tech may have regulated to compensate for the growing brackets. She told me that would certainly NOT be the case as I am the first piano technician to ever sit down at the piano since it was purchased new, 30-some years ago. :-0
It needs a bit of tuning (duhhhh - will be done after new brackets are installed) and was 60 to 100 cents flat.
So, anyone pretty darn sure where I should look for the year of manufacture in Pierce?
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Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com
813-684-3505
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