Pianotech

Greetings all,

I have a 1925 Hindsberg (Danish), which has the original Schwander-type butt springs. A previous technician had also installed American-type springs, presumably due to the weak originals. The original springs are indeed too weak to function properly, and the new springs are too strong, resulting in a 70-90-g DW. I'd like to remove the new springs and replace the originals, but as seen in the photo, the design is different than the modern version. Is there a way to modify the old butts? (Replacing all the butts, if even possible, would probably be cost-prohibitive.) 

I have tried to strengthen the old springs and weaken the new ones--neither worked. De-activating a sample original spring had little effect on DW.

Any way to fix this piano? It was rebuilt a few years ago, but the spring problem wasn't addressed then, possibly due to cost.

Photo attached. Note the old spring and the way it's "threaded" into the butt, and the new groove constructed for the American-style replacement springs.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Scott,

The torsion spring pictured cannot be adjusted (bent), or any spring for that matter, and expect to have any range of pressure adjustment. Bending only changes the range in which the given pressure begins and ends.  The given pressure is determined by the wire size. My read on this is to make new springs with a different wire gauge.

Greetings all,

I have a 1925 Hindsberg (Danish), which has the original Schwander-type butt springs. A previous technician had also installed American-type springs, presumably due to the weak originals. The original springs are indeed too weak to function properly, and the new springs are too strong, resulting in a 70-90-g DW. I'd like to remove the new springs and replace the originals, but as seen in the photo, the design is different than the modern version. Is there a way to modify the old butts? (Replacing all the butts, if even possible, would probably be cost-prohibitive.) 

I have tried to strengthen the old springs and weaken the new ones--neither worked. De-activating a sample original spring had little effect on DW.

Any way to fix this piano? It was rebuilt a few years ago, but the spring problem wasn't addressed then, possibly due to cost.

Photo attached. Note the old spring and the way it's "threaded" into the butt, and the new groove constructed for the American-style replacement springs.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Roger, 

Thanks. What about modifying to take modern springs? In examining my photo, I wonder whether there would even be room because of the proximity of the shank to the spring. Drilling a hole might even put it through the shank. The spring resides in a pretty shallow recess. I'd probably have to somehow deepen the groove so the that the coil sits in a position to receive chord to hold it in place.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033

Original Message:
Sent: 10-29-2024 15:42
From: Roger Gable
Subject: Double-sprung dilemma

Scott,

The torsion spring pictured cannot be adjusted (bent), or any spring for that matter, and expect to have any range of pressure adjustment. Bending only changes the range in which the given pressure begins and ends.  The given pressure is determined by the wire size. My read on this is to make new springs with a different wire gauge.

------------------------------
Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000

Original Message:
Sent: 10-29-2024 14:20
From: Scott Cole
Subject: Double-sprung dilemma

Greetings all,

I have a 1925 Hindsberg (Danish), which has the original Schwander-type butt springs. A previous technician had also installed American-type springs, presumably due to the weak originals. The original springs are indeed too weak to function properly, and the new springs are too strong, resulting in a 70-90-g DW. I'd like to remove the new springs and replace the originals, but as seen in the photo, the design is different than the modern version. Is there a way to modify the old butts? (Replacing all the butts, if even possible, would probably be cost-prohibitive.) 

I have tried to strengthen the old springs and weaken the new ones--neither worked. De-activating a sample original spring had little effect on DW.

Any way to fix this piano? It was rebuilt a few years ago, but the spring problem wasn't addressed then, possibly due to cost.

Photo attached. Note the old spring and the way it's "threaded" into the butt, and the new groove constructed for the American-style replacement springs.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Roger, 

Thanks. What about modifying to take modern springs? In examining my photo, I wonder whether there would even be room because of the proximity of the shank to the spring. Drilling a hole might even put it through the shank. The spring resides in a pretty shallow recess. I'd probably have to somehow deepen the groove so the that the coil sits in a position to receive chord to hold it in place.

Scott,

The torsion spring pictured cannot be adjusted (bent), or any spring for that matter, and expect to have any range of pressure adjustment. Bending only changes the range in which the given pressure begins and ends.  The given pressure is determined by the wire size. My read on this is to make new springs with a different wire gauge.

Greetings all,

I have a 1925 Hindsberg (Danish), which has the original Schwander-type butt springs. A previous technician had also installed American-type springs, presumably due to the weak originals. The original springs are indeed too weak to function properly, and the new springs are too strong, resulting in a 70-90-g DW. I'd like to remove the new springs and replace the originals, but as seen in the photo, the design is different than the modern version. Is there a way to modify the old butts? (Replacing all the butts, if even possible, would probably be cost-prohibitive.) 

I have tried to strengthen the old springs and weaken the new ones--neither worked. De-activating a sample original spring had little effect on DW.

Any way to fix this piano? It was rebuilt a few years ago, but the spring problem wasn't addressed then, possibly due to cost.

Photo attached. Note the old spring and the way it's "threaded" into the butt, and the new groove constructed for the American-style replacement springs.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------

Scott,

Your concern about proximity to the shank is justifiable, but from the photo it does appear to allow you to drill a hole through the side of the butt to insert a retaining center pin without encroaching into the shank. It's hard to see from the photo. Adding the Schaff 3736 mentioned by Nathan appears to be a possibility, although the wire gauge may be incorrect. You just have to try them.

P.S. I'm not sure what you mean by "modern springs"

Roger, 

Thanks. What about modifying to take modern springs? In examining my photo, I wonder whether there would even be room because of the proximity of the shank to the spring. Drilling a hole might even put it through the shank. The spring resides in a pretty shallow recess. I'd probably have to somehow deepen the groove so the that the coil sits in a position to receive chord to hold it in place.

Scott,

The torsion spring pictured cannot be adjusted (bent), or any spring for that matter, and expect to have any range of pressure adjustment. Bending only changes the range in which the given pressure begins and ends.  The given pressure is determined by the wire size. My read on this is to make new springs with a different wire gauge.

Greetings all,

I have a 1925 Hindsberg (Danish), which has the original Schwander-type butt springs. A previous technician had also installed American-type springs, presumably due to the weak originals. The original springs are indeed too weak to function properly, and the new springs are too strong, resulting in a 70-90-g DW. I'd like to remove the new springs and replace the originals, but as seen in the photo, the design is different than the modern version. Is there a way to modify the old butts? (Replacing all the butts, if even possible, would probably be cost-prohibitive.) 

I have tried to strengthen the old springs and weaken the new ones--neither worked. De-activating a sample original spring had little effect on DW.

Any way to fix this piano? It was rebuilt a few years ago, but the spring problem wasn't addressed then, possibly due to cost.

Photo attached. Note the old spring and the way it's "threaded" into the butt, and the new groove constructed for the American-style replacement springs.

------------------------------
Scott Cole, RPT
rvpianotuner.com
Talent, OR
(541-601-9033
------------------------------