Question about commonwealth tender trucks
Posted: Mon Nov 25, 2013 8:22 pm
Question about commonwealth tender trucks bolster for frame link arrangement. I'm working on a set of freelance truck castings (no prints, of course) and I cannot figure where the swing link pin holes should be positioned relative to the upper swing link pin holes on the frame.
The holes for the swing links on the frame are fixed at 4-3/8" apart at the top of the truck frame. When I drill the holes for the lower swing links in the bolster, I can make the distance wider than the frame holes (a), the Same distance apart as the frame holes (b), or smaller than the frame hole distance (c).
Each position seem to have some influence on which side of the bolster lifts when it swings side to side, but I can't wrap my head around what moves (the truck?), what is stationary (the bolster?) relative to the frame and track.
?What should it be - A or B or C?
Regards,
Denis
The holes for the swing links on the frame are fixed at 4-3/8" apart at the top of the truck frame. When I drill the holes for the lower swing links in the bolster, I can make the distance wider than the frame holes (a), the Same distance apart as the frame holes (b), or smaller than the frame hole distance (c).
Each position seem to have some influence on which side of the bolster lifts when it swings side to side, but I can't wrap my head around what moves (the truck?), what is stationary (the bolster?) relative to the frame and track.
?What should it be - A or B or C?
Regards,
Denis