Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Shanks with parallel wood grain

When shanks break in the middle, it's usually on an angle, because that's the way the wood grain goes.

There's a way to make shanks with the grain parallel to the shank. It's a trick from 17th century furniture making. I've seen antique chairs with really long narrow turned spindles in the backs. The way they did this was to split the material for the blanks instead of sawing it. At first, I thought that splitting was a really crude firewood kind of idea. But using it to get parallel grain is a surprisingly clever technique.

For shanks, you'd probably want to start with pieces about 6 - 8" long, and split them into squares of 3/4" to 1". Center them up and turn them on a lathe, and you get shanks with the wood grain parallel to the surface of the part.

Clearly they'd be stronger against breakage, like those antique chairs. Would there also be an advantage where twisting and warping are concerned?

That's very interesting. I would think it would also help with twisting and warping.

More wasteful?

It is not so much a trick, but 1) knowledge that most have forgotten because of mass production and 2) a lack of artisans making their own parts and focusing on the smallest of details.

Many high quality wooden objects (e.g., violins) have been done this way for centuries. By splitting the wood, instead of cutting through it, you can see how the wood will move with changes in temperature and humidity: it allows you to predict stability!

Does it effect the sound on violins? Probably not, but since dimensional stability-- especially under force--is a significant issue with hammer shanks, then it makes sense to do this.

Greetings,

Mass production hasn't forgotten anything, it is a question of how much quality is a manufacturer willing to buy. If you want only perfectly aligned grain, you will throw out 90 % of the wood you buy. If QC allows more imperfection inre alignment, you will throw out less wood. It is all on a continuum, and wooden parts makers are making compromises vs. costs, all the time. Wooden parts will never be perfectly consistent throughout the set, hence a built-in source of irregularity due to material that milling will not circumvent.

Anytime you hear a manufacturer declare that they are "uncompromising", you are hearing, if not lies, a clear case of "puffing". That is the legal term that allows this sort of statement.
Regards,

it is named "killing the nerve of wood" (in French)

About quality and consistency, I wonder if some of you have chase for bowed shanks in a Renner set for uprights.?
SOme can be find but very rarely. resiliency gives about a
3d when they are tested by sound and a few can be thrown out.
I compared with other brands and the quality was really different.

They are mounted with their eventual bow in direction of the player, to avoid lateral motion with moisture change, even if they are more supple that way.
I have find both grain orientations in uprights, but most are mounted in the most supple direction.

As someone told me once "in pianos all fiber grain is vertical but the keys"

The flanges are better flat sawn. That way when they swell they get wider more than they get taller.

This thread is really about why synthetic is the way to go. The weaknesses -- as well as benefits -- of wood are built in.