Machinist's solution for tonebars buzzing on harp supports

[voltergeist]

This is a solution I came up with for tonebars buzzing against the harp supports.  The harp support is .060" thick, so I took .020" off each side (which left .020 of material in place), of a size and position appropriate for the adjacent tonebar.

[voltergeist]

[pianotuner steveo]

Nice!

[Tim Hodges]

Nice, I remember when Vintage Vibe did something similar a while back:

http://www.youtube.com/watch?v=suq_DY7Bs64

[voltergeist]

I don't remember seeing that vid before.  Nevertheless, I think I've got a much better solution.  With all due respect to VV, there is very little strength left when 90% of the material is removed (there's only about 3/16" of material left!).  .020" is enough to give the tonebar breathing room, and the strength of the bracket is not compromised.

[Fred]

Nice, I remember when Vintage Vibe did something similar a while back:

http://www.youtube.com/watch?v=suq_DY7Bs64

Not sure who came up with that mod. I agree with voltergeist though, there is not much material left to offer proper support.

In a pinch (or failing the skills of a machinist), you can slightly grind the mounting area of the tonebars and/or the washers to prevent any contact with the brackets. This can be done without any adverse effect on the sustain of the affected notes. I would however refrain from grinding #54 tonebar. Modify #53 and and bend the bracket away from 54 (as #54 is straight, and you do not want to grind mass away from the vibrating end of the tuning fork). 

[David Aubke]

How about a compromise? Why not cut out a slot leaving the top and bottom of the bracket intact?

[voltergeist]

How about a compromise? Why not cut out a slot leaving the top and bottom of the bracket intact?

One could do that, but it's not ideal for a few reasons:
-The length of the cutouts needed aren't the same on both sides (especially on the high end, since the tonebar on one side is flat and on the other side is twisted).  A through cutout to accomodate both would remove more material (and therefore weaken the bracket more) than necessary.
-Leaving material in place maintains shape and strength
-If you're machining, might as well do it the elegant way

That said, cutting all the way through is viable, if not ideal.  Leave as much material as possible on the top and bottom, and don't make the cutout any longer than necessary.  Drill holes on each end, cut between them with a jigsaw, and touch it up with a file. 

It's a pretty quick and easy job for a machinist, so one might be better off marking the area and taking them to a machine shop.  Or, if you don't want to go machine-shop hunting, message me and I can do them for you.

[David Aubke]

Yeah, I meant it for those of us without a mill.

Did you do anything to protect the metal where you removed the surface? I don't know what those braces are plated with but they're the one piece of metal in the whole piano that always seems to remain in near-perfect condition.

Cutting a slot would expose bare metal as well.

[voltergeist]

Yeah, I meant it for those of us without a mill.

Did you do anything to protect the metal where you removed the surface? I don't know what those braces are plated with but they're the one piece of metal in the whole piano that always seems to remain in near-perfect condition.

Cutting a slot would expose bare metal as well.

That's a good point, I have to admit I hadn't really considered corrosion.  Probably masking off the area and spraying a clear coat would do the job.

[Ben Bove]

Depending on which tonebar is hitting up against the bracket, usually a light hammer swing at the bracket in the other direction'll take care'a that.  hahaha (insert picture of gorilla)

Very clever idea.