Athearn 0-4-2t - binding gears?

Hi all,
I'm hoping someone out there remembers the Athearn "Little Monster" 0-4-2T from the 1960's.
After several months detailing, painting, etc. et. al., everything was
fine. Until one day I heard a horrible noise. . .one of the crank pins had come loose, and dropped the rods.
For whatever reason, after that the engine would occasionally bind up.
I've tracked one problem down to a bent crank pin. .. and just got some crank pins in from Bowser.
Replaced the bent one, and it's running much better, but still getting an occasional bind.
Before finding the bent crank pin, I made sure the frames and rods were all free from burrs, checked the worn gear and the axle gear for defects, and cleaned up a few rough edges.
Is it possible that the gearbox shifting/rotating could cause the universal coupling to jam? Could improper quartering cause an intermittant issue, or would that cause a constant issue?
I'm wondering if the gearbox is supposed to be held stable by a brace or what not (it wants to rotate on the axle axis, since the universal allows some room for this). As I got this (extremely) used, I'm not sure if it would have had some kind of brace.
If so, I noticed NWSL has a gearbox kit for the old 0-6-0 - I'm guessing it'd be pretty close - they mention the rotation issue, but say just to make the worm shaft as long as possible.. .no mention of bracing the gearbox.
Anyway, I'm obviously new to dealing with gearing/rods/ quartering. . .so any thoughts would be very welcome.
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peitz wrote:

Yup, cute li'l beast, I detailed and painted one back then, and sold it to a friend.

Yes, improper quartering could be an intermittent issue, since there is some slop in the side rods, but theer has to be an additonal factor. IMO, it's possible that the jamming loosened the wheel on its axle just enough to a) out it out of quarter, and b) allow it to move more or less into and out of quarter from time to time.
It's also possible that the other crank pins are bent just enough to cause a problem, but not enough to see. Or are loosened in their holes. So try replacing them all, not just the one that's obviously bent.
If you added valve gear, that might be bent, too, and again, just enough to cause occasional grief.

The gear box should be held in line with the motor shaft. Athearn could have made the gear and motor a single assembly by tying them together with a brace. That would have required a higher precision in several components so that the gear would mesh properly when the motor was bolted onto the frame. The universal joint was expected to take up any slight misalignment between motor and gearbox. Not the best design decision IMO, but it lowered the cost, and it works.

Um, which 0-6-0? Do you mean the MDC/Roundhouse one? The NWSL kit for it might fit into the Athearn 0-4-2, but I have my doubts. OTOH, it may be possible to make it fit. Just don't use too big a sledge hammer. ;-) Anyhow, if the gearbox is connected by a shaft rather than a universal joint, it won't rotate. The shaft braces it.
Back then, I disassembled an MDC 0-6-0 that the club had "inherited." It waddled down the track like a demented duck. It needed a new main driver, the old one was shaped like an egg (a duck's egg, no doubt.) After cleaning, reassembly with a new driver set, and repainting, the club had a very handsome switcher.

If you intend to continue messing around with steam engines, get a NWSL quartering tool. It's also a gauge: you can tell if all drivers are quartered the same. Worth every cent.
HTH
--
Wolf K.

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Check out the Athearn exploded diagram at:
http://hoseeker.net/assemblyexplosionAthearn/Assembly%20Explosion%20Athearn%200-4-2T.jpg
There is no brace. The worm and gearbox are held in fore and aft position by the motor bearings and the universal joint. I opened my old Little Monster and mine does not "want to rotate on the axle axis" - the worm and gearbox are held on pposition by the univerxsal which does not have much play. The diagram at the HO Seeker site shows a ball #90109 that should snap into both parts of the univesal to hold them together. Could this ball be missing on yours and allowing some excess play?

If the drivers are out of quarter and not slipping on the axle, the bind usually shows up as a regular "hitch" in the same position during each revolution of the drivers, as you suggest. but if a driver is loose on the axle so that it can shift in and out of quarter, you can get occasional binds. Make sure your drivers are not slipping on the axles.

On my Little Monster the clearance between the side rod screw on the front drivers and the rivet on the back of the main rod at the crosshead is very tight. I am not having a problem on this loco, but I have had others where a little play in the axle will let the driver shift enough on a curve to cause intermittent contact of these parts, which shows up as a "hitch" or bind. You should check that your loco has adequate clearance here with the driver and crossheads wiggled to the extremes of their side to side play. Good luck. Geezer
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WOW! I love this group. Where else could you ask about a 40 year old engine and get great responses so quick?
I did just receive my NWSL quarterer - I'd ordered it a while back guessing that I might have a quartering issue. I will try it out ASAP. I did notice that this engine uses half axles, pressed into a center piece with the quartering grooves. I'll have to try that out.
The assembly diagram is awesome. I got this used (obviously) in non- running condition quite some time ago. I had no idea that it was missing the main boiler weight, either ( I weighted it, in any case). From my memory of checking all the drive train, I am, indeed, missing the little plastic ball. I'd already contacted Athearn a while back to see if they might still have any of these parts - and they don't. Any thoughts on how I could replace that ball? A ball bearing, maybe?
Thanks again for all the help.
Is there a way to post pictures on this group (after all the wire bending/fabricating I did on this thing, it'd be nice to let someone else see it :) )??
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Athearn does list: 90108     COUPLING, PLASTIC BALL Which seems very close to the 90109 in the diagram. Think it might still be the same ball, as the Athearn universals still look pretty much the same?
If not, what about using rubber hosing instead of the universal?
Thanks again,
Michael
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wrote:

(SNIP)
Rubber or neoprene tube is sometimes used, but I find it is stiffer than a universal joint, and since it is almost always sold as a coil, usually has a permanently set curvature, both of which can cause vibration in a model drive.
Athearn stopped using the separate ball in their U-joints (perhaps because they were getting lost too often) and all later diesel drives has the ball cast in to one end of the U-joint. This is the part that usually winds up inside the flywheel on Athearn diesels, so it may be difficult to find a substitute for use in the Little Monster. As an alternative, I have found the set of drive line parts offered by A-Line to be very useful in doing repowerings. See http://ppw-aline.com/re-power.htm and look for item #12030. These are all designed to be compatible with the Athearn drive line components. Geezer
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Geezer wrote:

Might Northwest Shortline hae an acceptable replacement universal with, or without, the ball that would be the correct size to take up the "slop"?
See, generally,
<www.nwsl.com>
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peitz wrote: [...]

No, this is non-binary group. Many ISP and new group hosts will strip out a binary post (picture).
Goto rec.model.railroad to post a picture. After posting the picture(s), notify the group. Make sure your subject line indicates the picture is of a model, eg, "HO Athearn 0-4-2T".
Looking forward to seeing the pics.
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Wolf K. wrote:
SNIPS

My ISP (Comcast) no longer carriesthat group. I was pretty uch "dead".
As a rec. heirarchy group, that group, too, was not a great place to post pictures. Lots of ISPs strip pictures and attachments from the rec. heirarchy groups.
Generally, an alt.binaries.whatever group is the better place to post a picture, if you have to post on a newsgroup.
A free account on Photobucket or some similar web site may be the best place for pictures, with a link posted here.
Make sure your subject line indicates the picture is

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jJim McLaughlin wrote:

OOPS, I don't know what I was thinking. Or if I was thinking at all. ;-) I wanted to type:
alt.binaries.pictures.rail
Dunno how come my fingers and my brain got disconnected.
HTH
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Wolf K. wrote:

Helps.
But don't sweat it.
Happens to me all the time.
Old timer's disease.
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Has been for prototype pics traditionally...
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Big Rich Soprano wrote:

True, but pics of models show up from time to time. Doesn't seem to bother anybody, and pleases some.
HTH
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Hey! Just like here!
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On 1/7/2008 11:00 PM Big Rich Soprano spake thus:

I don't think so; post pictures here and you're likely to make a lot more enemies than friends.
I'm just sayin' is all.
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I know - no worries mayt!
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The purists will FORBID you to do it but let er rip is my motto!
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On 1/5/2008 7:14 PM Geezer spake thus:

http://hoseeker.net/assemblyexplosionAthearn/Assembly%20Explosion%20Athearn%200-4-2T.jpg
A little off-topic, but I just have to comment on this. If you haven't looked at this diagram, please do so now. It reminds me again of just how much we've lost since the Great Dumbing Down which followed on the heels of Using The Computer To Do Everything.
I mean, how many CAD monkeys today would even *dream* of trying to create such a drawing--and a beautifully-rendered one at that--WITHOUT A COMPUTER? This was done way back in the days of T-squares, technical pens, and *skill*. (The date on the drawing is almost exactly 48 years ago, by the way.) Those skills are, for the most part, history.
For more examples, check out the gorgeous drawings of steam locomotives that still appear in /Model Railroader/, etc. These too used to be done by hand (like the old ones by Al Armitage that /Mainline Modeler/ used to reprint before they went under).
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David Nebenzahl wrote:

Sir,
I'll start by saying that I spent 17 years on a drafting board doing mechanical design before CAD came along (1993 for me). Any mechanical design concept in an engineer's head is, by definition, three- dimensional. When the only layout tool you have is a drafting board, the first task you have is to reduce your idea to just two dimensions, and that for me was always a daunting one. It tends to have a real chilling effect.
When CAD became available, it was like a great weight being lifted. I don't mean AutoCAD, which is just an electronic drafting board, but solid modeling. Suddenly, you can express and work out your ideas in all three dimensions. You instantly know the weight, area, moment of inertia etc. of all the parts. And everything fits together the first time!
Once the parts and assemblies are modeled, and exploded versions created, drawings are just a couple of clicks away. As an example, I offer this quick drawing I put together of a design for a model loco I am working on...
http://home.mindspring.com/~macindoe/513433.PDF
A computer is just a tool, like T-squares and technical pens. You can use a T-square just to scratch your back, a technical pen just to clean out your ear and a computer just to rant on newsgroups. However, in skilled hands each can do much more.
The skills we need develop and change. How many people do we need now who can make a buggy whip, or true up a wooden wagon wheel, or make mud bricks? The Luddites will be left behind while the rest of us move forward.
Bill MacIndoe
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that being said the highest paid machinist in the shop I work at are the two guys who can operate the the non CNC machines. This is because any monkey can load parts into CNC mill or Lathe were it takes a true machinist to turn out the same part manually

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