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Looking for information on Baldwin Concert grands that have roll pin hitch pins. Need to find out what the downbearing requirements are, where replacement pins can be gotten, and what issues you folks have encountered in the replacement and adjustment of the pins. I have 2 grands one a 9 foot and one that another tuner has asked about that I believe is a 7 foot. The smaller one has tuning issues and he believes it has to do with the pins not being strong enough. He says that they seem to flex when tuned. I have not seen this piano personally, several hours away from here, so I am going on his assessment. Any information would be appreciated. Thanks.

Replacement pins can be had at most hardward stores. They are just 3/16x1 (I believe) cold rolled steel pins and they are plenty strong enough - however they will bend if the string gets too high on the pin above the plate.
Cannot recall what Baldwin specs for the height limit but if the string gets more than half the height of the pin or 1/4 inch above the plate I would begin to get concerned.

7/32 roll pins. The only reason for flex would be that Baldwin occasionally set the plate height ridiculously low compared to the height of the finished bridges resulting in wires wayyyy off the plate. Even then it's probably not the 7/32" roll pins. More likely the overly tight pin block or some other factor preventing stability.

Baldwin sets the bass at about 1/2 degree, the midrange at about 1 degree and the upper treble slightly higher.There would be no reason to reset the bearing unless you plan on changing the plate height, the hammer bore and a lot of other things. Look for de-laminating bridge layers, bad pinblock fit, incredibly high pinblock torque and poor hammer technique first.

I have three pages of Baldwin factory repair procedure specs on acu-just hitch pins for both the SF10 and the SD10 and can provide if it would be helpful.

I tuned a concert vertical today and the strings were all more than 1/4" above the plate. In fact I think all of them were more than half way up the pin. some of the bass strings were 1/4" from the top of the pin. Should these be tapped down ( after reducing tension on the wire) to half way or lower or just leave them alone?

If this is a Baldwin, two verticals were manufactured with acu-just hitch pins: 6000 (52") and I believe the early run of the 248 (48"). Both often arrived from the factory in the way that you describe. Tech services always told us leave hitch pins and bearing values as set by factory. And so we did.

This has reference to Baldwin only and not to Gibson, as does the link to factory specs for repair procedures for acu-just hitch pins in Baldwin Artist Series Grands. I do not have the data on the 6000 or 248. Perhaps someone else has this. (I notice that Gibson introduced these hitch pins to other vertical models. Big mistake in my view.)

Link: http://pianotechno.blogspot.com/

Why a big mistake? Designed and used properly the vertical hitch provides an excellent string termination. Used improperly, of course, they can be problematic but that is true with just about any technology.

ddf

It depends on the string bearing. The position of the string on the hitchpin is dependent on the position of the plate relative to the soundboard and the height of the bridges.

And here is the downside of the vertical hitchpin string termination system. Workers who did not understand the dynamics of the system tended to use the system to compensate for sloppy bellywork and plate setting. It didn’t matter if the bridges were cut too tall—just set the strings higher on the pins. It didn’t matter if the plate casting was out of spec—just set the strings higher on the pins. It didn’t matter if the plate was set low on the belly—just set the pins higher on the pins.

Ideally the strings should never be more than 3 to 5 mm (≈ 0.12” to 0.2”) off the plate surface. On some Baldwin pianos I’ve seen them as high as 19 to 20 mm (≈ 0.75 to 0.79”). This is getting into the range where the structural integrity of the plate is in question—they can break. It is also in the range where pin bending becomes a significant detriment to piano tone.

The question is, “When you encounter a piano in the field with strings riding high on the vertical hitches; what can be done about it?” And, in the real world the answer is, “Not much.” It all goes back to string bearing. If the string bearing is more-or-less correct as is then lowering the position of the strings on the vertical hitches will overload the soundboard. To correct the situation would involve either raising the elevation of the plate or lowering the height of the bridges. Neither of which are tasks easily performed in the home.

ddf

Thanks for the replies. A# 1, left string, has to be replaced. should I set it likes it's neighbors, hi on the pin? The piano also has a rather pronounced metallic edge to the tone from the f3 at the break up to the treble break. Could this be a downbearing issue due to the wire being hi on the pins. I'm not really eager to change anything, but this piano is a regular customer and has always has this metallic edge on the midrange. I buffed the hammers to clean out the metallic residue in the string grooves and this helped, but still not that nice Baldwin sound I expect. It is the 6000, 52" vertical.

Yes.



It is probably not a downbearing issue. You can’t tell from the position of the strings on the hitches—you have to actually measure string downbearing to know what is happening there. I’d guess the sound you are hearing is coming from the hammers. I don’t know what you mean by “buffing” the hammers but…Baldwin used fairly hard hammers on these pianos; harder, in my opinion, than they should have been. You may have to do some voicing. And hope that no one has been in there first with the lacquer bottle!

ddf

Thanks again for the reply, Del. What I mean by buffing is that I take a soft brass-bristle brush and lightly buff the crown of the hammer. Not enough to remove any felt, just clean it up a bit. I does restore (temporarily?) a nicer tone. In this case all the metallic edge is not gone. I usually do this for my tuning customers. It provides a bit of 'extra service' and their piano sounds better than with just a tuning. I'm almost sure no one as hardened these hammers. This piano was purchased new and has had nothing but tuning done. I don't think there was much dealer prep either. If this buffing treatment is temporary, I'll try some light needling in the midrange. I want to proceed carefully so I will be quite conservative.

Thanks again for the reply, Del. What I mean by buffing is that I take a soft brass-bristle brush and lightly buff the crown of the hammer. Not enough to remove any felt, just clean it up a bit. I does restore (temporarily?) a nicer tone. In this case all the metallic edge is not gone. I usually do this for my tuning customers. It provides a bit of 'extra service' and their piano sounds better than with just a tuning. I'm almost sure no one as hardened these hammers. This piano was purchased new and has had nothing but tuning done. I don't think there was much dealer prep either. If this buffing treatment is temporary, I'll try some light needling in the midrange. I want to proceed carefully so I will be quite conservative.

I still have the instructions for using the Baldwin Bearing Gage that I got from them 25 or 30 years ago. The tool itself is pretty straight-forward and could be made easily. If I get some time this weekend, I might be able to scan the instructions and make it available.

BDB, I for one would like to read that if you get a chance.

Yes BDB, that would be interesting. Baldwin is one of my favorite pianos so knowing more about working on them would be great.

There I go making wild accusations again
Sorry, Del.
This had mosty to do with a chronic service problem that acu-just technology gave rise to both in verticals and grands. In virtually all cases where we performed either warranty work or a customer-pay, when a string had been replaced, the tech (whosoever he or she might have been) placed the loop anywhere but in the correct position. Typically, we found these flush against the harp! This may not have been the experience of Baldwin techs elsewhere. I can only speak to the central Arkansas area pre-Gibson.

This, of course, has nothing to do with the engineering, and everything to do with sloppy service. As a termination point it is fine and does have its advantages, and when a tech knows how to set the bearing, it is especially-fine. I do believe that the technology creates an interesting challenge in tuning but that is another topic for another day.

Your point is well made. In spite of the efforts Baldwin made to educate dealers and technicians about the function of this system and how properly to service pianos using it there were (are) always a few who simply didn’t (don’t) get it.

I remember once teaching a class at a PTG Conference on how these things worked and how to service them. Even how to restring them and properly set string bearing from scratch. There was one guy in the class who was clearly having a problem. I wasn’t sure just what his problem was but I clearly wasn’t getting through. He came up after the class and waited a few minutes while others asked me their questions. Then he lit in—the school he worked for had recently received two Baldwin Model R grands and, why, the quality control was so bad the factory hadn’t even properly seated the strings all the way down on the hitchpins. He’d had to go through both pianos and seat the strings himself and this really knocked the tuning out and he’d had to actually lower pitch on both pianos and they sounded pretty bad as well! The whole story came out in kind of a rush. I didn’t immediately answer any of his complaints; partly because he was talking pretty aggressively and didn’t give me much time to get a word in but mostly because I was simply speechless. Fortunately one of the techs standing next to me stepped in with something like, “You stupid idiot! Didn’t you hear anything that was said in this class? You’ve just ruined two great pianos!” This saved me from saying the same thing which, diplomatically—since I worked for the company—I really couldn’t say in quite those words. I have no idea what ended up happening with the pianos but it was indicative of just how ignorant some technicians (I use the term loosely in this case) could be.

As you say, this was one of the two major drawbacks of the system. The other was that some factory workers seemed to think it gave them license to place the plate anywhere; the stringers could always make up for it by simply setting the strings higher. Or lower, though this was rarely a problem.

ddf

Did he mean the sound of cracking wood? I guess that does sound pretty bad! Ouch.

I feel sorry for the guy. But on the other hand, I guess that being aware of downbearing is pretty basic after all.

I have a few questions in this context.

1) Is the Baldwin Bearing Gauge one of those three-footed tools that is placed with the center foot on the string where it crosses the bridge?
2) Are the bearing surfaces of the three feet in a straight line (plane)?
3) Is bearing measured with a feeler gauge on the termination side, after tipping the tool so that it touches the speaking length?
4) If there is any such thing as an "average", what would a typical bearing angle be?

I ask this because I would like to machine myself such a tool, and I have a feeler gauge. From the thickness of the feeler gauge and the distance between the tool's feet, I could calculate the bearing angle.

If BDB's scanned instructions will answer all my questions, then I'd kindly ask that he make them available here (or send it to me via PM).