[CAUT] Friday puzzler

[Kent Swafford]

There is an old saying from electronic music that says, "Every parameter that can be controlled, must be controlled."

Since removing a key lead improved the situation, it would be good to know up weight, down weight, front weight, the strike weight, and the action ratio.

If the friction calcs high, then you can continue looking for rubbing, etc. If the friction is normal or low, and/or if the up weight is low, then this may be a case of out-of-whack action.

I bring this up, even after you have the note in question working, because if one key didn't want to return, there might be 87 more  close to doing the same thing. I wouldn't focus on changing the key height as a "cause".

Look at the whole action.

In 2010, on every action we service, it is possible to be in touch with the relationships of ratio / front weight / strike weight and avoid many of the surprises that have bedeviled piano service for centuries.


Kent





On Jun 28, 2010, at 8:41 AM, Paul T Williams wrote:

> I removed one key lead and it now is working much better.   
> 
> I still don't understand why it was working until I took off the stack and then put it back on after raising the sharps a touch, checking the keys, lubing the key bushing cloths and balance rail cloths, polishing the front and bal. rail key pins, etc. You know, just general maintenance stuff.   
> 
> There was and still is, no debris, no tight centers, capstans good and polished (no burrs), wip cushions all good, hammers swing at 7, keys nice and free, no tight balance holes, pins not catching on fronts or backs of mortises, key dip remained at factory spec, key height factory specs (now including the sharps :>) ), rep springs weren't gunked up and are as strong as they should be, etc. 
> 
> I will blame it on little piano gremlins! 
> 
> Thanks for all the suggestions to check.  I learned a couple other things to look for next time something is wrong.  I have 8,800 other keys to play with!   
> 
> Best, 
> Paul 
>   
> 
> 
> From:	Paul T Williams <pwilliams4 at unlnotes.unl.edu>
> To:	caut at ptg.org
> Date:	06/27/2010 02:12 PM
> Subject:	Re: [CAUT] Friday puzzler
> 
> 
> 
> 
> Nope. 
> 
> I've tried switching wips, hammers.  Nothing is catching.  I didn't change anything else.  Just put the original wip back in just now and still no progress.  With hammers up and away.  I put in a new wip and it was worse. ???? 
> 
> I pushed down on the origianl wip and key and comparing it to a neighbor, properly regulated, it feels quite a bit heavier on the push, so Im getting closer. no prob on the mortises, key, balance, holes, jack cushion or any of that.  there are 4 leads in the front of the key, so maybe I should take out a lead.   
> 
> But WHY did this action behave before I took the stack off the first time to raise up all the sharps as they were too low?  This is a natural key which had nothing done other than raise up the blow distance a bit? Why I always get the weird stuff is beyond me! 
> 
> Looking for more input, please. 
> 
> Paul 
> 
> 
> 
> 
> 
> 
> From:	Jon Page <jonpage at comcast.net>
> To:	caut at ptg.org
> Date:	06/25/2010 07:28 PM
> Subject:	Re: [CAUT] Friday puzzler
> 
> 
> 
> 
> 
> I've had this happen: Front rail pin contacting front edge of mortice.
> That took a long while to track down. Now I always check it when a
> key is sluggish for no apparent reason.
> -- 
> 
> Regards,
> 
> Jon Page
> 
> 
> 

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