Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I fussed with the endcaps, shifting and tightening them down
in different ways.  I even ran it while tightening to see if
that slows it down but that is not the problem.

So, I let it run at the fastest 'smooth' speed for several hours
(well lubed) and this is the result.  The chattering rolling-in-
the-bushing sound always starts at the same speed (slower is
acceptably smooth) then smooths some when I increase it.  Therefore,
I'm guessing this is a harmonic problem that is only bad at
certain speeds.  Of course, if there was no bushing play it would
not happen at all.  To that end, I'm going to inquire about
the price to buy another set of machined end castings.  There may be
a way to use ball bearings as there is extra metal in the bearing
area.

Wayne