Ha! Small world!
Now I wonder if the two Oriental NP A Class northern's from the same estate went to a fellow TRW member. Anyhow, back to Max's very informative tutorial.
Max, I watched some of your youtube videos, impressive work on the streamlined PSC K4. Super smooth!
Phillip
Thanks! That was a particularly good one.
They don't all come out that smooth. The rod and axle locations on these are not the greatest. The center driver is
geared, but drivers 1 and 3 are rod-driven. That's fine... as long as you precisely make the rods, rod holes, and crankpins,
and your axles are located exactly the correct distance apart in the frame to match.
But if not, you have a push-me-pull-you problem where the drivers go around, and kind-a don't, then get caught up, and so on.
That is often the case on these PSC engines, and then, they can only be made to run so well. If you hold one in your hand and
hold the center driver (geared) still, the rod-driven drivers can turn back and forth an alarming amount. There is too much slop
in the rods/holes to really make for accurate running. They probably did this because it gets the whole thing to
at least work, and they couldn't make the parts and frames precisely enough to limit all the slop so they would all work
well.
The crankpin holes on, say, a Kato Mikado or C55, on the rod-driven drivers, are quite precise. That's one of many reasons the Mikado
runs like it does.
