pitman retrofit

[Jon Page]

>Well, I suggest when yours start making noise you let us know and 
>I'll do the same.  I simply don't see the ANY logic in replacing the 
>same with the same...the brass pitmans and all of the other wooden 
>pitmans all had rounded polished ends at one time...and they all 
>creaked...it wasn't the bushed hole in the keybed...

It is the sliding friction on the OEM pitman which causes the creaking.
As the pedal is depressed and since the pitman is restrained vertically
in the bushing, the pitman becomes closer to the fulcrum; hence
the scrubbing. With a replacement pitman being fixed on the radii, the
pitman swings further from the fulcrum. Think of a tangent drawn to a
radius, a point 1/2" from that radius is going to be further from that tangent.

By your reasoning you should replace the pedal rods with dowels with
leather or felt on the ends so they won't develop creaking.

I have been thinking of switching to a 5/16" dowel simply for the ease of
fabrication. The ends would be polished and lubrication in the socket
but it is a broader surface which might induce more friction and run
the greater risk of creaking but since the sliding motion is replaced by
pivoting motion the risk is low. Next time I pull the action on this M in
the shop I'll examine this forwards excursion to see what size dowel
would accommodate (without having to remove material from the hole)
but looking at the trapwork just now, the majority of this forwards motion
is at the tray with the rod mostly pivoting below.

Wasn't the wooden pitmans replaced with the metal ones in order to
reduce friction because of the higher polish achieved on the ends?
-- 

Regards,

Jon Page
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