Adjusting keys elevation (how is it called)

[RodionGork]

Dear Gurus!

Right-side keys of my old PA do not form precisely straight plane with their faces. I understand that it is just a matter of bending the rods, connecting them to valves. These on the picture below.

But after I've fixed a couple of them, I get puzzled - what should be keys optimal (or original) height at all?

Now, when pressing a key, it sinks down for about 10 millimeters or more. However far less movement is needed to open valve and produce the sound. So I believe this could be reduced to 4-5 mm. Would it be a good idea?

 

[debra]

10mm is most certainly way too much key travel. How much the accordion was designed for can be hard to determine if they were all wrong. Often you see that a few keys are a bit out of whack and then the other keys make it clear what the key height should have been. Often also there is a strip of (not too soft) felt under the keys that reduces keypress noise and at the same time also reduces the key travel. On an old box that felt may need replacing and that will already reduce the key travel by a 2 or maybe even 3mm.
Less key travel allows for faster and easier playing (less finger movement). A PA may have a bit more key travel than a CBA but 5mm should be enough. The black keys should not go down more than to 1 or 2mm above the surface of the white keys (that are not pressed). That travel distance then should be similar to the amount of travel of the white keys, give or take a mm.

 

[Soulsaver]

Dear Gurus!

These on the picture below.

I see no picture?
But yep, the keys started life level, so usually better to inspect/renew the pallet felts before bending rods, unless someone else has been in there with their spanners... (one of my projects was a right mess.. the rods had teeth marks all over them....).

 

[artelagro]

I agree. It is always best to understand how it was designed then think what could have altered over the years. In almost all cases it is the soft leather pads that have found their new shape through regular use.
Garth

 

[RodionGork]

Friends and Gurus, thanks a lot for your advice!

After your warnings I decided not to do rush changes

I only went through white keys to made them more equal and eventually lowered most of them by 2-3 mm so they are also equal with the upper/bottom edges, which made it simpler to check the line with ruler. I found it is not always easy to bend the rods yet preserving the proper position of the valve. All the black keys have far shorter rods and they seem to be still well leveled.

The felt under the keys seem to exist still, though it is not easy to disassemble the keyboard in my case. Keys do not knock when lowered and land on some thin but yet soft layer...

 

[kimric]

I often use the sides of the keyboard as a reference. You can lay a straightedge across them and then just the keys so you can just slip a piece of paper under the ruler. I wold use this as a starting point. Other adjustments might be needed.

 

[jollyrogeraccordions]

I normally make a little wooden gauge so that one side sits on the edge of the keyboard while the lip of the key is up against the other side of the gauge. This will give you a very consistent and flat keyboard - well, for the white notes that is . I occasionally find it necessary to reset the pallets too, if I have introduced air leaks by adjusting the levers.