Loose crankpins in the Bachmann EM-1

[carlso]

Max,

I read and printed your thread regarding B'mann EM-1 repair. Excellent write up and very timely in my case. The EM-1 fell to my garage floor when I was shaving it to accept the AC-9 boiler casting. I was able to connect the expansion crank but never thought about anything else. Today, while test running and checking out the sound decoder the darned thing jammed up so I dug out your article. The crank pin on the fireman side of the 2nd engine was so loose I don't understand why it hadn't fallen out. I tightened it and all seems to be OK now. The other 3 were tight.

My question is, should a  thread locker be used on those screws or would that just create more problems down the road when repairs are needed? My guess is to just live with the screws and check them before and after an extended running cycle.

Carl

[mmagliaro]

Carl,
First, can you rename this thread to "loose crankpins in the Bachmann EM-1"
or something like that?  It would be more useful to people reading through the topics than
looking at my name 

Once a crankpin comes out once, I generally do not trust it.  It *could* be that they just didn't tighten it
at the factory, but my experience has been that they usually come undone because the motion of the rod
works them out of there no matter how tight they are.  So once one comes loose, I want something in
there to make sure it doesn't happen again.

This is the same reason I put LocTite into axle/wheel hole joints after I fix up and engine that has had
drivers slip to throw off the quartering.  I assume that "it's only a matter of time" before other ones slip.

Personally, I like using a little drop of LocTite on the threads of crankpins.  I use the Green variety,
which I find to be easy to use, holds well, and if forced, especially in a crankpin (whether threaded or pushed in)
can usually be coaxed out of there if it really needs to be.  (the most popular are the blue and red... but this
green stuff has shown up in some hobby shops around here and I really like it)

Except for a driver that has a traction tire on it, the times you need to pull or unscrew a crankpin are extemely
rare.  It happens when something breaks or slips out of quarter, and that's much less likely to ever happen again
if you have LocTite on there.

If you are squeamish, you could use a drop of ACC instead.  That will keep the pin from unscrewing, usually.
And ACC can't hold anything for beans so you can always get the pin out if you have to.

[carlso]

Thanks for the reply Max. Me squeamish? If I had been, I would have never, in my right mind, attempted this EM-1/AC-9 bash.

The crankpin did tighten up, but I think I'll loosen it a bit and put a very tiny drop, from a needle point, onto the threads and cinch it down again. I have the blue bottle of Permatex and it is "Medium strength", so I'll try it. Life gets in the way sometimes, so I have not had a chance to run the loco and watch all of the expansion links and eccentrics for proper operation. I shall do so before I make this fix. The other three crankpins were tight. Of course the crankpin is on the traction tired driver.

Thanks again,

Carl

[carlso]

I test ran the EM-1 chassis again today with no luck. The crankpin did not stay tight and the eccentric just sits there and the crankpin rotates around it. I looked at the expansion link and naturally it is doing nothing as it should be rocking back and forth. I checked and the contact points seem to be loose enough to not cause a bind that would cause the eccentric to not work properly. I'm afraid there are no threads left on the crankpin. I really don't know what to do. I will cal Bachmann tomorrow but I rather doubt if they will have any replacement parts for the EM-1. Truly lost.

Carl

[victor miranda]

Hi carlso,

threads?

can you do a close photo?

I can think of a few fixes.  and you are past some of the easier ones.

please consider new parts from b-mann.
this is also the easiest option IF they have the part(s).

worst case is careful drilling and gluing a sleeve in there.

easiest idea and hardest in practice is to epoxy the crank in place.
a little epoxy in the wrong place and you have a tough repair ahead to get the
loco going.

phone b-mann first.

victor

[mmagliaro]

If the crankpin had threads and the hole is now stripped out, I can think of several ideas.

Yes you could call Bachmann, and they will probably want you to ship the engine back and charge you for the repair
since you've been tinkering with the engine, obviously.  They might be able to sell you a driver set, but those
aren't that cheap.

You can fill the hole with JB Weld, let it harden, drill a small hole, then tap it with a metal screw that is the
right thread (probably metric, and probably M1.0 or maybe smaller).

You could just fill the hole with Loctite, shove the crankpin in there and be done with it.  Might work.  Might not.
But worth a try.

The way I see it, if the hole is that bad and Bachmann just wants to charge you to do a repair (find that out),
you have nothing to lose by trying.

Of course, you could always send it to me or Victor or others on this board, and I'm sure one of us can fix you up.

[carlso]

 Victor and Max,

I contacted B'mann and they have no repair parts for the EM-1. What a surprise. I don't think any manufacturer makes replacement parts, except by accident. Today, I will remove the crankpin to get a good look at it and then go from there. Victor, I think that I can get a picture, so I will try.

Thanks for the replies, I appreciate the help.

Carl

[mmagliaro]

Bachmann generally has a ton of parts for their steam engines and they regularly restock them - better than most companies do.

You're just caught at a rotten time: The EM-1's parts haven't been made available yet.

Yes, pictures would help.  I'm having a hard time understanding why a crankpin can't be gently screwed back into a hole with some LocTite
or epoxy to get it to stay put, even if the threads are completely shot.