Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Una corda stop felt

Can anyone advise on a good type of felt or cloth to use for the una corda stop on the left side of a grand action? I don't think I have ever seen this particular piece being called out by name in literature or distributor catalogues.

It is usually thin white action cloth.

it is not unacorda stop, if this is on the left in the cavity, that piece locare thé action lterally.
very important to have the hammers well centered under the choirs, before moving many shanks right the condition of the cloth is checked, and shims can be added behind the wooden piece.

the stop for UC is usually a piece of leather in front of a flat head screw,located at the right of the action, generally on the right cheek block.

before shimming the left, double check the strike position, as a little bit more inside and many hammers are right, orleft of the choir

white action cloth indeed, firm cloth, sèomething that does not compress much (it can be thin this is not a problem)


end of the basics ....

Thanks Olek and BDB.

I was aware that the flat head screw on the right hand side is what's referred to as the "stop", but had never heard of a specific name being given to the left side, which is why I also referred to it as a stop.

The wooden piece (left "stop") on this particular piano is glued to the frame, so I won't be able to shim it. Instead I think I'll experiment with either thin or medium action cloth, whichever gives me the best average hammer location.

you can nail the cloth or glue it only on the extremities, then shim as/if necessary behind.

I dont know the name, I thought a rest cloth

It is usually called a rest block and the felt is the rest felt. It needs to be quite firm.

Thanks, good action cloth is rare and expensive, I have seen solutions using a thin cloth (not felt) , that where not too noisy, carboard shims behind the cloth;

if the clothis mushy, we can iron it before installation, also compress it in a vice (stabilise the thickness)