Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum False Beats-V Bar Shape and Pressure Bar height

That's the American assembly line philosophy. Get as many units out as possible and fix the problems afterwards. Don't ever stop production.

Oops! It looks like I posted the same link twice. This is the additional link I wanted to post:

http://daniokeeper.tripod.com/webonmediacontents/ktsg_10.pdf

I don't understand your meaning.

I thought the same.

Don't you damage the bridge's wood by tapping on the pin towards the string?

These were Kimball's published recommendations at the time for their pianos that were under warranty.

I had a Kimball dealership as a customer.

As I recall, at that time, Kimball had either laminated hardwood bridges or laminated hardwood caps. Also, the bridge pins were not short; they extended higher above the bridge... as I recall.

Even though it was about 30 years ago, I do remember questioning to myself at the time whether to follow these recommendations.

But, it was a Kimball piano and this was Kimball's recommended solution. If I ignored their advice and just went my own way, how could Kimball be responsible for honoring the warranty?

I did use this exact method successfully several times to correct buzzes. Of course, you're not hammering them like a nail. You just want to bend the pin maybe a few thousandths to stop the noise. Don't tap them at the base where the pin contacts the bridge. Tap near the top.

This rarely needed to be done, and then only on one or two pins.

The O.P.'s piano is a 1970's piano, not 1980's like these service manuals. He'll have to use his best judgment.

Some of these 'correct' procedures I always found questionable. Yes, a Philips screwdriver will slip out of the screw head and damage it before over torquing will twist the head off. Many high quality tools today are pozidriv especially those of European origin. They are not designed to slip out of the screw head and so can easily twist the head off those cheap screws. They are designed for craftspeople who can feel the torque even in a tight screw before it reaches dangerous levels. The Phillips system seems more of a diy affair or for factories where screws are driven in with a powerful drill.
The pressure bar was a soft material that would bow between the screws if tightened with string tension on and which of us would take the tension off a new piano where we are fighting for every bit of stability on a piano that may be back on a delivery truck in a few hours and most likely never be serviced ever again?

Like Joe, we all had to rely on our personal experience of higher quality instruments and some inventiveness to find legitimate, quick and safe ways to solve manufacturing problems.

The servicing booklet was an accurate reflection of the factory.

Preferably bend the bridge pin on the non-speaking length side of the bridge. The back pins.

Absolutely! If possible. Sometimes the back pins were not accessible because of obstructions.

Fortunately, this was not a routine correction.

Another issue re the false beats the OP mentioned...
At the time, i was instructed that the pianos would arrive at the dealership at "a pitch higher than A440." My instructions were to tune the piano at that higher pitch at the dealership and then at A440 in the customer's home.
This I ignored. I always brought them back down to A440, which always took extra time. They would then want to start creeping back up in pitch. If I didn't do it this way, the piano would start creeping back up in pitch once tuned to A440 in the home.

It can be more challenging to bring a very sharp piano down to A440 than to raise a flat piano up to A440. As you lower the tension on some strings, the tension on the other strings increases. You risk string breakage and other damage. So, it might take several passes to do it safely. And at that time, I was working without an ETD.

Also with brand new Kimballs, the pins were so very tight in the block that the pin would twist considerably before the foot would even begin to move.

Though it was 30+ years ago, I think I remember being told that Kimballs received only 5 or 7 tunings before leaving the factory. I've always suspected that they were tuned very sharp to try to help settle them faster, and this contributed to the false beat problem.

It is possible to damage a string without breaking it by using too much tension.. pulling it too high.

Basically given the tendency of flagpoling front bridge pins to cause false beats, having the pin bent away from the anchoring wood on the other side seemed potentially problematic.

But It didn't register for me that you could only do it to the back bridge pin as Ed said...

Here's an update.

I did some work adjusting the pressure bar, realigned several trichords and tuned the piano. It's a big improvement. I also put it back together (music desk, fallboard, keyslip etc) and that made even more improvement in the overall sound. I think a lot of my problem with the sound of the piano was the harsh buzzing, which is much less noticeable with the piano back together. I can play a major 7 chord, and it sounds good which I couldn't do a month ago.

Thank you all for your assistance.

I have posted on the same problem with trichords on my 1945 B.Brock upright. For me it was the fact that some of the stings were too close.
All I did was loosen the ofending strings then just below the capo bar I pushed in small bits of hard plastic to move the strings away from each other. This does not look too good but then who plays an upright with it's front off!
You may have some troble where strings run close to a capo screw. I recon that the odd screw left out would probably not make much difference. Failing this one could, if there is space move a hammer side ways.
If I were to ever buy another piano then agafes(sp) would be essential.

Hi Goof, Using shoe pegs to separate the strings is traditional. It goes way back.

There were a number of problems with Kimball pianos of that era. They were budget pianos that lacked design finesse and construction quality.

In today's market they also lack anything like top (or even medium) dollar. Hence anything you do to the piano will have to be charged to "education." You will not be able to recover the cost of any significant improvements you might make to the piano. You can, however, learn a great deal. So it's a question of how much you are willing to spend on education.

There are undoubtedly problems with the bridges. It wouldn't be a mid-20th century Kimball if there were not problems with the bridges. Assuming the string offset is adequate (not always a safe assumption with Kimballs) then a drop or two of thin CA adhesive on the back side of the pins can help. Otherwise more heroic measures might be required.

Ed McMorrow is quite right in his comments about the steel rod used as a V-bar in these pianos. It was used because it was cheaper to cast a groove in the V-bar and set in the steel rod than to surface the as-cast V-bar. The steel rod is too hard and, perhaps more importantly, it is not well seated. Examine the V-bar groove -- it is rough and uneven. (At least it has been on every Kimball of this type I've ever had the misfortune of servicing.)

There is not much you can do about the string spacing problems except try to space the strings as best you can. But if you want to do some educational experimentation there is a lot you can do to improve the performance of these pianos. Most of which will involve restringing the piano.

You can evaluate (and greatly improve)the string scale. You can clean up the bridges. You can replace the steel rod with a brass (or bronze) rod. And, while you're at it, you can bed that rod so that there is a better, more solid, termination of the speaking length. Bed it in a filled (preferably with iron powder) epoxy. It's not difficult. Just fill the "U" indent on the top of the V-bar with your epoxy matrix and set (and figure out how to clamp) the new rod in place. When cured clean everything up and you're good to go. (This will, by the way, help even the steel rod.)

All of this goes way beyond what is economically practical on a Kimball piano of this price. The payoff is in education. Only you can determine whether this is worth the investment in time and treasure.

ddf

Thanks for the tips Del. I would like to try the new V-bar, but I need to spend my time dialing in my tuning first; this seems like a project that makes sense once I'm already in the field.

Del, do you know of a place to locate hardness specs for phosphor bronze compared to mild steel or annealed drill rod? I'm looking for a supply to use regularly for capo inserts but thought you might know off hand a supplier and grade that you would recommend. I just had an old model "O" with a terrible amount of issues in the capo and corresponding tonal issues. Lots of voids and casting sand embedded in the surface. Ended up using annealed drill rod and it sounds great but always interested in trying something a bit more appropriate.

Nice to see you back on PW a bit.

Dale

I go to my very old (1986) copy of Materials Handbook. If it's not in there you probably don't need to be using it.

I haven't purchased any of this for a long time but I think my last batch came from "Online Metals." I could be wrong.

ddf

Dale Fox, It might be less work to just drill the capo for upside down agraffes.

Yes. I often get overagitated with small pianos because of their harsh and loud Asian hammer attacks but it is amazing how different it sounds with the cover back on. Back on false beats: in the Riblitz book there is a section on this and one of the things he mentions is pitch raises causing false beats. A small kink or bend in the string can cause what I call " termination confusion" which is a false beat. So a piano that was as messed up on the tuning as you described might be problematic temporarilly even without the other problems you mentioned