I have an Oriental Limited USRA 2-8-2 and unfortunately the crank pin detached from the axle and a rivet detached on the valve gear. Fixing it is above my skill level. Any recommendations for someone who does repairs for this type of problem?
Thanks
Did the pin break off in the wheel?
Here is the situation:
https://imgur.com/a/1vj1H6i
The crank pin fits onto that shaft somehow. It does not seem to screw on..Im not sure what held it in place. the front of the rod disconnected as shown.
As shown, that ought to be an easy fix, with a little care.
Look at the other side of the engine to determine which way the eccentric crank is set to advance. It will be installed on the visible 'pin' so that the crank end either leads or trails the driver crankpin angle by 90 degrees, and the actual angle on an electrically-driven model will not be critical.
There was probably an 'interference fit' holding the crank on the pin -- in other words, it was pressed on. You might want to use a tiny amount of adhesive to hold it a bit better if that fit is now sloppy: use due care not to glue up the main and side rod action if you do. In my not-so-humble opinion, even a light love-tap on the crank eye with a flat hammer would probably close up the bore 'enough' for a tight fit...
The other end of the rod just needs to be pinned into the eye of the "fake" valve gear. The catch is that you don't want to remove all the valve gear from the locomotive, which is what you'd need to do to use the (otherwise-excellent) Bowser valve-gear-rivet setting tool.
If you are not averse to holding a nut in thin-jaw pliers, you could use a small screw and nut to pin this -- the nut going behind, the screw being cut short to just engage the nut so it doesn't bind anything "behind" as the joint moves. You could take a small strip of plastic or brass and temporarily stick the nut to it, for example with double-sided Scotch tape, to get the screw aligned with and threaded into the nut, then tighten a bit further if necessary. Apply a tiny dab of some sort of glue to the outside of the nut (on the hidden side) with a toothpick to secure the joint.
If you want to use a Bowser rivet, you might want to drill or ream the eye of the rod and the hole in the gear to fit. The correct "tool" to fit this in place will have the mushrooming pin of the Bowser setting tool on one side of a set of thin parallel-jaw pliers (something like this might well be available from jeweler's supply houses). In operation you would lay the engine on its side, arrange the rods to match what's on the other side, put a hole in one or two small pieces of paper to use as spacers and place them aligned with the holes in the rods, and drop the rivet through the whole shebang from the outside, then carefully squeeze with the pliers to form the 'mushroomed' securing head on the other side. Someone like Ed can provide the Bowser tool instructions, which you're basically following with a squeezing motion rather than lightly tapping with a hammer.
A kludge solution would be to make a plastic "rivet" out of some material like sprue, with a flattened and filed head, inserted from the backside and then mushroomed (and filed to shape) with a tool like a small soldering iron. I think we have had a couple of threads describing this sort of procedure, including the best plastic materials to use.
This is NOT terrifyingly difficult, and no step would permanently damage your engine beyond easy recovery.