[pianotech] Monkey Help Needed

[Ron Nossaman]

Carman wrote:
>   I have a client with a 1902 Chickering grand and I am trying to 
> restore the sostenuto function.
> I have successfully adjusted the distance between the sosenuto rod lip and
> the tabs on the dampers so it can work.
> The problem is that the monkey keeps slipping off the top of the pitman.
> Sometimes it skips forward and sometime it slips backward.
> 
> My plan is to drill a hole in the bottom of the monkey and in the top of 
> the
> pitman and insert a "top pin" in the top of the pitman.
> I'm thinking that the hole in the bottom of the monkey should be a little
> oversized to allow a fraction of fore-and-aft motion in the monkey.
> 
> I need your critique and your ideas.
> 
> The monkey is identical to the one pictured in "Piano Parts and Their
> Functions" in the upper right illustration XVII on page 37.
> 
> Carman Gentile RPT


There's a Chickering with a Steinway style monkey? If so, how 
can it slip off the pitman when it's constrained fore and aft 
by the spring, and port and starboard by the guides? Doesn't 
geometrically compute. If you pin it to the pitman. how does 
the next poor sucker pull the action? Again, doesn't compute. 
A rational real world mechanical assessment of what's there 
will determine the fix. Perform one, or find someone who can.
Ron N