Kimball Stack Questions
By Steve Harder
I've bounced this off Les but thought I'll poll the group.
The continuing saga of our Kimball baby grand. The expression box works well, is adjustable, plays the Recordo test reasonably well, I'm going to borrow some Recordo rolls locally to finally hear what that's all about.
The bleeds that I've cleaned did improve the repetition rates of the pneumatics, so that project is productive.
My general sense is that the stack is not very tight.
I've got 5 or 6 notes which 'hiss' after the pneumatic has pulled close or hiss when the pneumatic is open. I'm assuming I've got leaky valve seats or holed pneumatic (the general state of the pneumatic cloth has been fine, I'm sure part of the '69 rebuild was cloth replacement.)
Also, as I've adjusted the expression box, my water gauge (measuring at the main hose inlet to stack) has shown I need 14-16" to sound notes on P reliably. At FF I'm only able to get to 25" using a small shop vac. Using a new '45"' suction box I'm only seeing 23". A friend's upright plays nicely on 10" or so. I'm sure all the bells & whistles on mine are 'lossy', but my naive conclusion is that the stack should be tighter than it is.
This brings me to my question. Up to now, I've stayed out of the stack totally (except for bleeds). The bottom of the stack has screws holding it together. All other parts of the player I've been into have been easily disassembled/assembled. No leather gaskets tearing apart, etc. (I'm in a do no harm mode here.)
Where am I likely to get into trouble if I drop the stack (3 large bolts and a grunt down to the floor) and try to clean/fix valves?
All pouches I've inspected elsewhere have been in good shape so I'm hoping they may still be OK. Reblitz says Kimball used a layered valve seat which Player Piano claims to have the parts for.
I also need to replace some leather hardware on the pushrods as I've lost 2 notes to failure of the upper nut while playing rolls. That part of project should be pretty straight forward if I do 1-at-a-time and keep adjustment the same.
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Steve Harder
slharder@center.iastate.edu |
(Message sent Mon 5 Feb 1996, 17:13:13 GMT, from time zone GMT-0600.) |
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