Punk Rocker Capstans

[Conrad Hoffsommer]

At 09:58 2/12/2004 -0600, you wrote:
>I am wrestling with a very nice old Haines Bros. upright that has the 
>two-screw rocker capstans directly connecting the keysticks to the stickers.
>
>I couldn't find much in the archives on regulating this kind of system. 
>Help if you can, please...
>
>The blow was 2 1/2" so I adjusted the rail for a 1 3/4" blow and the keys, 
>of course are now all horribly uneven.
>
>Since the action is all linked, any changes to blow distance, rocker 
>adjustment (lost motion), and key height will all interact, working as a 
>system.
>
>So how does one regulate such a beast?
>
>Alan R. Barnard
>Salem, MO
>



I haven't run across these, either, but

Musing out loud...

Sinceeverythingislinked, and since the action must go through let-off, I 
think that I would first set a sample let-off.

Then you play with blow distance, key level and dip until you find a 
combination which doesn't bury sharps, break off ivories on the keyslip, 
show felt under the fronts of the naturals or feel like a harpsichord with 
1/4" dip and no power or aftertouch.

The keys need some space below the name board, so that would determine the 
highest the key level _could_ be.

The capstans should be somewhere in the center of their range of motion so 
that some adjustment can be made in either direction. If you can't get them 
adjusted to have a little aftertouch and still have them in the midrange, 
you have to change something else.

Since the key is as high as it can safely go because of the fall/nameboard, 
the next things to adjust would be the blow and/or dip.

If the dip is such that you aren't burying the sharps and you have massive 
amounts of aftertouch, (like you continue to drive the hammer into the 
string), you probably should increase the blow distance.

If you aren't getting _to_ letoff, you have too much blow distance.

Again, play with a sample before you do any global changes.

Why did you shorten the blow so much? That sounds like a spinet.





Conrad Hoffsommer - Music Technician
Luther College, 700 College Dr., Decorah, Iowa 52101-1045
Vox-(563)-387-1204 // Fax (563)-387-1076

- Education is what you get from reading the small print. Experience is 
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