Accu-Just hitch pin questions..

Posted by: 7naturals

Accu-Just hitch pin questions.. - 02/04/13 03:37 AM

Dear Group,

The piano I am interested in is a late 90s Baldwin grand that has the accu-just hitch pins. The piano is far away so before I go see it I asked for some pictures. When I looked at the picture that showed the hitch pins I could see that the strings look to have been tapped all the way down to the plate. They were not in the center or a little below center of the pin like I have seen on other Baldwins that have those pins. I cant see under the bass strings in the pictures, but looking at the bridge that goes all the way across that you can see, all the strings look to be down at the bottom of the pin touching the plate.
I could be worrying for nothing and maybe there is a good reason the strings were put all the way down to the plate . Still though I am concerned from things I have read about improper string placement, downbearing, and have a few questions.

1]With the strings put that low on the pin could that have damaged the piano.[bridge,sound board]

2]If the strings are positioned wrong and need to be re- leveled , can this be done accurately and without damaging anything, how long will it take to do that, and is it expensive.

3]If the piano had been stored for some years with the strings incorrectly positioned on the hitch pins and then it is repaired, could there be problems later. I.E. tuning, tone, bridge or sound board problems, stability etc.

Thanks everyone and I hope I asked the right questions.
Posted by: Ed Foote

Re: Accu-Just hitch pin questions.. - 02/04/13 08:56 AM

Greetings,
I have never seen accu-just pins with the strings tapped all the way down. Usually, they are in the middle of the pins. If they were supposed to be much higher, there is a tremendous amount of down bearing pressure being created with them all tapped down. You should have someone experienced in Baldwin pianos measure what is going on at the bridges.
Regards,
Posted by: Del

Re: Accu-Just hitch pin questions.. - 02/04/13 01:45 PM

Originally Posted By: Ed Foote
I have never seen accu-just pins with the strings tapped all the way down. Usually, they are in the middle of the pins. If they were supposed to be much higher, there is a tremendous amount of down bearing pressure being created with them all tapped down. You should have someone experienced in Baldwin pianos measure what is going on at the bridges.

I have. On several pianos. It’s one of the reasons why, for the two Walter grands, I specified a solid pin with an annular groove that hold the string in a fixed position.

Over the years I’ve heard from technicians—in some cases the term must be taken loosely—who have complained that Baldwin pianos were defective because the strings were not seated against the plate and so, to properly serve their customer, they had accomplished this important task. And is this a repair that is covered under warrantee and how much should they bill the factory?

I’ve also heard from technicians complaining that Baldwin’s spring pins were defective because they couldn’t be bent back; “I tried to do a couple of them and the first two broke so I didn’t do any more.” And then, “How difficult is it to remove them and put in ‘proper’ hitchpins?”

It is possible that the string frame was originally installed high requiring that the strings be set very low but it was more common to see them with the string frame installed on the low side with the strings set a little high on the pins.

The original concept of the vertical hitchpin—along with Baldwin’s “floating” string frame mounting system—was to provide a manufacturing system in which the bridges could be machined to a fixed height; drilled, notched and pinned on a bench and assembled to the soundboard panel and the whole assembly installed in the skeleton and thereby avoid doing all that time-consuming bridge work in the piano. In theory this was a pretty good concept and design, tolerances were fairly tight and the process proved to be very efficient. But in practice—I suppose because the system was so adjustable—assembly sometimes got a little sloppy in which case the strings ended up riding too high on the pins. (Usually. I’ve seen them some on the low side but usually they were too high.)

As you say, if the correct setting for the strings on that piano was in the “normal” range and they have been tapped down, the integrity of the board is now in question. Whether or not the soundboard assembly would suffer any permanent damage depends on how much excessive string bearing there has been and on how long it has been there. I’ve known of pianos that have been treated this way that were brought back to life with no apparent side effects and others with cracked ribs. Baldwin used a combination of panel compression and crowned ribs to achieve overall soundboard crown and, if anything, they tended to be somewhat over-ribbed. Once the excessive string bearing load has been removed—assuming the ribs haven’t cracked—the boards can spring back having suffered no apparent long-term damage.

(Note to 7Naturals: Your technician should carefully check string bearing angles and soundboard crown; if he/she is experienced and knowledgeable the problem—if any—will be readily apparent. If I was evaluating at a piano that had been treated this way for a client I’d probably recommend that they pass; there are too many uncertainties. If I was considering it as a rebuildable core I wouldn’t worry about it—the soundboard assembly would most likely be replaced anyway.)

I like the concept of the vertical hitches but I was never very enthusiastic about how Baldwin used them.

ddf
Posted by: Olek

Re: Accu-Just hitch pin questions.. - 02/04/13 02:08 PM

"Baldwin used a combination of panel compression and crowned ribs to achieve overall soundboard crown and, if anything, they tended to be somewhat over-ribbed. "

That may be why I find part of their tone to be of the kind I appreciate the most, with a very fast "answer" to solicitation.
Posted by: 7naturals

Re: Accu-Just hitch pin questions.. - 02/04/13 04:03 PM

Thanks all for your answers.
Del from what I have researched its like you say, either the plate not installed right or someone that wasnt familiar with the Baldwin system tapped them down thinking they were too high up on the pin. I hope its just the way the picture was taken but it looks clear to me. I called where the piano is and they are going to have a tech call me and look into it.
Question:
If it is confirmed the strings are at the bottom of the pin as they look to be from the picture, but the tech says there is no visable damage to the board or ribs and there is good crown, should I still consider it, or do you think there may still be some hidden problems and pass on it.

I will try to find out how to post a picture on here so you can see what it looks like..
Thanks again..
Posted by: Del

Re: Accu-Just hitch pin questions.. - 02/04/13 05:11 PM

Originally Posted By: 7naturals
Thanks all for your answers.
Del from what I have researched its like you say, either the plate not installed right or someone that wasnt familiar with the Baldwin system tapped them down thinking they were too high up on the pin. I hope its just the way the picture was taken but it looks clear to me. I called where the piano is and they are going to have a tech call me and look into it.
Question:
If it is confirmed the strings are at the bottom of the pin as they look to be from the picture, but the tech says there is no visable damage to the board or ribs and there is good crown, should I still consider it, or do you think there may still be some hidden problems and pass on it.

I will try to find out how to post a picture on here so you can see what it looks like..
Thanks again..

Hopefully it just looks that way in the pictures. Not being able to see either the pictures or the piano it is impossible for us to tell. We also don’t know the model of the piano. We do know it was built in the late 1990s at a time when Baldwin was having increasing quality control problems.

Baldwin string bearing was specified in degrees of deflection across the bridge. Typically in a newer piano these would be from about 1° to 1.5° in the treble section decreasing to about 0.5° at the low tenor and bass (a little less in short grands). I’d not worry if the angles were a little less than this in pianos more than 10 or so years old. If they are significantly higher than this I’d worry.

Baldwin used crowned ribs in their pianos but the crown radius was fairly large (an unloaded radius of 72’) and this will increase—i.e., the amount of crown will decrease—as the soundboard is loaded. You don’t say where the piano is located but if it is in a relatively dry environment the soundboard crown will also be a bit low. It is not unusual to find these pianos with essentially flat boards after a few years. If, however, your technician records negative crown I’d be a little suspicious.

ddf
Posted by: TunerJeff

Re: Accu-Just hitch pin questions.. - 02/04/13 09:21 PM

Del,

I have the Baldwin spec-sheet on adjusting the deflection for the AccuJust pins. It is available in the Pianotech or CAUT library on the PTG Forum site. It also includes their 'Guide to Stringing'.

You can find it there...or send me an eMail and I can heave it your way. Ditto to the technician who needs to 'fix' the 'fix'.

;-)

Thanks for the input!
Smiling,
I remain,
Yr. humble and ob't svt.,
Posted by: 7naturals

Re: Accu-Just hitch pin questions.. - 02/05/13 12:04 AM

Del,

Well here is the picture I was talking about of the hitch pins. To me it looks like the strings are at the bottom of the pin. Virtually no space between plate and string. Hopefully its just the picture.
Thanks for your input....


Posted by: Del

Re: Accu-Just hitch pin questions.. - 02/05/13 12:19 AM

Originally Posted By: TunerJeff
Del,

I have the Baldwin spec-sheet on adjusting the deflection for the AccuJust pins. It is available in the Pianotech or CAUT library on the PTG Forum site. It also includes their 'Guide to Stringing'.

You can find it there...or send me an eMail and I can heave it your way. Ditto to the technician who needs to 'fix' the 'fix'.

I expect I have one or two around somewhere. Depending on which version you have I may well have helped write it back in my Baldwin R&D days.

The numbers I gave from memory will be pretty close. (I think.)

ddf
Posted by: Del

Re: Accu-Just hitch pin questions.. - 02/05/13 12:20 AM

Originally Posted By: 7naturals
Well here is the picture I was talking about of the hitch pins. To me it looks like the strings are at the bottom of the pin. Virtually no space between plate and string. Hopefully its just the picture.
Thanks for your input....

I think they are just low. It's hard to tell from the fuzzy picture but I think there is a little clearance in there. I'd rather have them low than high.

ddf
Posted by: BDB

Re: Accu-Just hitch pin questions.. - 02/05/13 01:56 AM

These seem to be the documents.
Posted by: TunerJeff

Re: Accu-Just hitch pin questions.. - 02/05/13 02:02 AM

Dear Del,

Hmmm. I don't have a date on the Tech sheet, but it appears mid-90's. It uses the Lowell Component Downbearing Guage, and states that the Baldwin 'rocker' tool is no longer available. Despite that; it includes deflection numbers for a bubble level, the rocker tool, AND degrees for the Lowell Guage.

Here's a bit from it...and it does read like a Fandrich..complete, informative, and useful. Could be, maybe?
;-)

Smiling,
Jeff

Baldwin Tech Sheet

•Downbearing should not be confused with crown. The following Tech Sheet excerpt explains:

Occasionally the question will arise concerning the proper way to measure crown on a soundboard. First, let’s differentiate between two related terms - crown and downbearing. Crown is the measurement of the spherical shape of the soundboard. The soundboard is often compared to the top of a violin in that the board is arched upward instead of having a flat shape. Downbearing is the measurement of the deflection of the strings as they cross the bridges.

Soundboards utilize a crown to help offset the downward pressure of the strings. Also, soundboards under tension will produce a fuller, more vibrant tone across the musical scale. The crown on a soundboard is normally designed to have approximately a 1/8” to 1/4” deflection in the middle of the board with the piano unstrung. However, once strung, the total downward pressure of the strings on the soundboard can result in a 400-1200 pound load that continually pushes the soundboard downward. It is the designed balance of the crown and downbearing that will enable a piano to resonate and produce tone to its fullest potential.

It must be stressed that crown cannot be measured on a tuned, strung piano. The downward pressure of the strings will prevent any accurate measurement of crown. Technicians will commonly attempt to measure crown with a string or straightedge along the underside of a grand parallel to a rib. This will only show crown in the loaded condition. The tone of the piano is a better assessment of the crown of the board. A full tone with adequate sustain is an effective indication of sufficient crown....

Etc!
Posted by: TunerJeff

Re: Accu-Just hitch pin questions.. - 02/05/13 02:05 AM

Dear BDB,

Huh! Hadn't looked at that in a while. Looks like 227 people have downloaded the info...so a few know what Baldwin had to say about it. I found the plate setting and stringing info interesting...Vaseline? Really?

Scratching,
the head,
I am,
Posted by: 7naturals

Re: Accu-Just hitch pin questions.. - 02/05/13 03:56 PM

Thanks everyone again for the input,

Del, Im confused now.. You mentioned if the strings were too low there would be excessive down bearing [pressure on the board] and perhaps board damage. In this post you mention you would rather the strings be too low than high.
So I am wondering now..hmm.
Well the question I have is one that I had posted . If the strings were improperly set after factory too low, but the tech finds no damage and there is still good crown , is the piano still good for consideration to buy , or would there still be a possibility of a hidden problem and I should pass on it.
Thanks again...

Posted by: James Carney

Re: Accu-Just hitch pin questions.. - 02/05/13 04:51 PM

It's so hard to tell from that picture exactly where the wire is in relation to the pins - why not have the seller take some additional close-up photos of the hitch pins in each section? I don't see any wires touching the plate from this photo, though.

What model Baldwin is this?

There were excellent Baldwins produced from the mid to late 90s. The SF-10 and SD-10 can both be extraordinary. The model L can also be wonderful. Condition is everything, though, so even if the soundboard hasn't been compromised by excessive downbearing due to a tech mistake, there will be plenty of other areas to carefully inspect before you buy. If the inspecting tech is knowledgeable and thorough, and doesn't rush the evaluation process, there shouldn't be any "hidden problems" that would escape notice.

And, just as if the piano wire is too low on the Accu-just hitches, it is also bad if the wire is riding too high. Why? Too much stress on the hitch pin.
Posted by: kpembrook

Re: Accu-Just hitch pin questions.. - 02/05/13 06:18 PM

Originally Posted By: James Carney

And, just as if the piano wire is too low on the Accu-just hitches, it is also bad if the wire is riding too high. Why? Too much stress on the hitch pin.


And high on the hitch pin causes what???
Posted by: Del

Re: Accu-Just hitch pin questions.. - 02/05/13 07:37 PM

Originally Posted By: 7naturals
Del, Im confused now.. You mentioned if the strings were too low there would be excessive down bearing [pressure on the board] and perhaps board damage. In this post you mention you would rather the strings be too low than high.

With the Baldwin style of construction there is no fixed height for the string frame. It can be installed a little high or low depending on several factors. The relationship that counts is the string deflection angles over the bridge.

If the string frame is installed a little high then when string bearing across the bridge is accurately set the strings will be sitting a bit low on the hitches. This is a good thing. I like the vertical hitchpin arrangement but I don’t like it when the strings ride high. My preference is for the strings to be about 3 to 5 mm off the plate surface. It’s hard to tell from the fuzzy picture but it looks to me that this is about where they are on this piano.

ddf
Posted by: 7naturals

Re: Accu-Just hitch pin questions.. - 02/06/13 08:52 PM

Does this look a little better.
Got some good photos close up and I am feeling better now.. thanks for all the help..




Posted by: Dave B

Re: Accu-Just hitch pin questions.. - 02/10/13 12:38 PM

Every time I checked, the angle of the string from the bridge to the Accu-Just hitch was negative. I call them the "self-Adjust" hitch pins.