Hi all,
I couldn't figure out how to change the title of the original post, but as the subject line implies, I could really use a picture of how the eccentric rods should be aligned on an MTH Railking Allegheny 2-6-6-6.
Thanks, and apologies four doubling up!
-Eric
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Thanks !!!!
Well, it's solved for now. I think...
Based on picture, I decided to visit my LHS to get his opinion/support. He confirmed what other posters inferred - that loose bolts were a problem on some units from the factory and the oiling the joint shouldn't have caused the problem. That was at least some relief. Some. I still feel like an oaf.
Anyway, he explained the alignment in detail and then tightened things down once it was set up correctly. There was also a tender cable alignment issue, so he showed me how to take the boiler shell off - very educational. Turns out the chassis was slightly warped! We were able to GENTLY straighten things and now the tender plugs in with no hassle.
When I got it home I ran it (somewhat reluctantly) around the layout at various speeds for around 20 minutes with no issues in forward or reverse. I now know what to look for so I'll be checking it frequently for a while, but I also know what to tighten, so as long as it doesn't happen at full tilt and I catch it, I can fix it.
Worse case: it cuts loose at high speeds and I don't get to it in time. It bends the heck out of the rods (not expensive to replace) and possible damages the motor (lso not terribly expensive). It is amazing how once you cast off your fears of something, it doesn't seem so grim. I confess that I never opened a steamer in any scale before, and now that I have, it doesn't freak me out.
So thanks for all the kind words and advice. Hopefully this thread helps someone else who runs into the same issue.
-Eric
Most modern steam locomotives have inside admission valve gear. The eccentric crank should be ahead of the axle (toward the cylinders) when the rods are in their lowest position. A broadside view of 765 shows this clearly.
But sometimes the crank is behind the axle (toward the firebox) on models. Lots of Lionel postwar steamers were set up that way. Both eccentric cranks are set up that way in klazys' photo.
When 765 is running, the eccentric crank follows the rods in a loping motion.
On a locomotive with slide valves and outside admission, like East Broad Top No. 15, the eccentric crank lopes in front of the rods.
These are little details that only keen eyes will notice.
Has anyone caused an eccentric crank to bind the valve gear by moving its position?
I moved the eccentric cranks on a few Lionel postwar steamers and they ran fine. Looked better, too. But maybe some scale steamers are designed to run with their eccentric cranks in a certain position.
Any replies?
I found a photo of Reading & Northern 425 at Jim Thorpe with her rods below center and her eccentric crank ahead of the axle.
I had a similar problem with my Imperial Y6b when i first got it a couple of years ago. One eccentric came loose and jammed, which bent the eccentric rod slightly. I simply bent it back, reset the eccentric, and tightened up the screw. Turned out two of other 3 were just as loose.
If you have one where it continues to loosen, a small dab of Loctite blue on the threads will fix it.
Rod
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