Kawai Aures capstan problem

[Pmillpiano]

Hi.

I went to tune a kawai Aures and one of the capstans had a large amount of lost motion. When I till the key out to have a look I could move the stem of the capstan up and down in the hole. I wasn't sure what to do, so I pushed it down as far as it would go and then wound the capstan back up to the right height ( which meant that now it's was high up on the thread).

A week later I was send an email saying it's happened again and there is more lost motion now.
Does anyone have any ideas why this has happened. I thought it may be a fault with the hole depth or something, but I really can't work it out.

[Barrie Heaton]

Remove the capstan, put a few drops of superglue in the hole, give it time to dry, and then put the Back in. It should Be Nice and Tight.

If it's very loose I get a cocktail stick and put an off cut of the cloth in the hole after the drops of super glue,


Barrie

[Pmillpiano]

Thanks Barrie.
What's the best watt to remove the capstan then. I've not taken them out of the hole before.
Can you just pull them out with some pliers?

Paul

[Barrie Heaton]

You turn them out they are threaded into the wood, obviously the wood has shrunk and they become loose.

Barrie

[Pmillpiano]

It's not the the screw in ones. these have a metal stem and then a plastic top part. I want sure what the end in the wood was like (if it had a pointed end it something to help drive it in) and didn't want to ruin the hole taking it out.
I thought I may have to get it out, fill in the hole and drill a new one.
It just seemed odd in a new piano for this to happen. It keeps dropping further down though
I've added a picture of that helps.

Thanks.

[Barrie Heaton]

Try a couple of drops of superglue at the base of the pin.

[chrisw]

I had a conversation with my tuner a few weeks ago about the repair of loose capstans and superglue was mentioned when the problem is caused by the hole in a wooden capstan expanding. These Kawai capstans seem to be made of a 'plastic' material so is superglue still appropriate? Are replacement capstan available from Kawai(UK)?

[Barrie Heaton]

The super glue is placed around the metal stem where it enters the woodt, not at the capstan part. As the capstones of these keys are normally fired in via machine sometimes they are sent to deep.

If the plastic capstan is loose then remove it and a few drops of superglue inside the hole but you must wait until it's dry.


Barrie