My steamboat pump has always had a slight knocking sound, which, by the
way, can be heard in most of my YouTube clips.

Upon closer inspection today I find that it comes from the cam rod hav-
ing a slight up/down movement at the motor end.  When I grab the cam in
the middle, it rattles just slightly if I jiggle it.

Today while the piano was in play mode, I held the first pair of lobes
(closest to the motor) open with my hands, and, since there was no con-
tact with the cam, all was quiet.  As soon as the lobes were free to
open and close again, the cam began knocking again.  The middle and
last pair of lobes make no noise when touching the cam.

Is it possible to adjust the cam to help quiet it?  Is there an adjust-
ment here that I have missed?

Daniel Cox
Worrigee, Australia