Repost: Help! My capstans are too short!

[Richard Brekne]

*********** REPLY SEPARATOR  ***********

On 27.05.2002 at 14:08 Tvak@AOL.COM wrote:

>List  (Hope this isn't a redundant post...I mailed this off this AM at
>10:08, 
>and as of 1PM it's still not on the list, so here it is again.
>
>I'm putting back together a Cable (Conover) 44" studio console and this AM
>I 
>had a few minutes, so I thought I'd take out the considerable lost motion 
>(1/8" at the front of the key!) and found that the capstans aren't long 
>enough to eliminate the lost motion.  The capstans are not short ones, 
>either.  They are 1 1/8" in total length, but to sit tight in the key they 
>protrude 15/16".   

Also... they are just 3/16th's in the key ?? Doesnt sound overly deep so I think we can assume the problem is not here ??

>
>I tried raising the key height but that didn't help.  I could put new 
>backrail felt in, which I think would help a little bit, but the present 
>backrail felt doesn't seem overly worn or compressed so it probably
>wouldn't 
>make that much difference.  

Putting a thicker back rail felt would lower the front of the key, requireing a bit more balance rail height to compensate.... This might solve your problem, but you need to make sure you end up with fronts that arent over the key slip and that you can get correct dip.

>The wippen felts have a depression where the 
>capstan sits, but doesn't every piano?  The depression doesn't seem
>excessive.

Probably not the problem either then.


>I did change the hammer blow distance which I assumed caused the lost
>motion, 
>but I've never had a situation where there was so much lost motion it 
>couldn't be compensated for, so I'm looking at other causes.  

Perhaps this is a borderline situation where changing hammer blow broke the proverbial straw ? Lots of things can cause your basic problem, from too thin a back rail felt to, the action mounting bolts being installed at the incorrect depth. And you dont really know all of who has done what before you do you ? But from what you mention below there are certainly some changes made that touch on the general problem area. New keytops, dampers, and levers could very possibly cause an inexperienced tech to unduly lower the keys. And perhaps he / she changed the backrail felt, front and balance rail felt punchings as well ??

So... 1 and 7/8 " hammer blow is a figure you should be able to make work. The capstans are probably right, which means that either the action is sitting too high over the keys, or the back of the keys are sitting too low under the action.

Take it from there.

Thats my initial read anyways.

Cheers

RicB


>When I got
>the 
>piano there were no cushions under the hammer rail at all and the blow 
>distance was close to 3", so I set it at 1 7/8".  Maybe I should increase
>the 
>hammer blow distance to 2" or 2 1/2".  That certainly would help.  I got
>the 
>1 7/8" from the Piano Handbook.  I wasn't sure exactly which of the models 
>listed under Cable referred to mine, but the largest hammer blow distance 
>listed for any of them was 1 7/8".  
>
>The piano did have some structural damage to the case which we repaired. 
>One 
>of the legs and the horizontal piece connecting the leg to the case at the 
>bottom was loose, and was reattached.   Maybe this changed the level of
>the 
>keybed and contributed to the lost motion?
>
>Other things I've done to the piano that I don't think would cause this
>but I 
>should mention to give the complete picture are:
>    new keytops
>    new damper felts
>    new damper flanges (the old ones were plastic)
>
>The client is looking forward to getting the piano next weekend...
>
>Any thoughts on a solution?
>
>Thanks,
>Tom Sivak


Richard Brekne
RPT NPTF
Griegakadamiet UiB