Author Topic: Commentary (need feedback from steam guys) - 2-8-0 Imported for HALLMARK MODELS  (Read 2366 times)

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seusscaboose

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ok sports fans...  get ready for this one...

I am in process of having my fathers vintage brass H0 scale 2-8-0 (Imported for HALLMARK MODELS... Made by Dong Jin Models) and have run across a snag and need TRW help / feedback.

the locomotive has been re-motored... (check)

We got rid of most of the binding in the valve gear mechanism but we still have a problem with the main driver and worm wheel.

This is the gear that drives all of the drivers via the side rods. The problem is this: Drivers are on the axles are crooked. This caused the drivers to lope . Lots of run out both side to side and up and down.

We are considering trying to press off the drivers and see if we can’t get them to set straight but we are afraid that if we do that we could break one of them (or both).

thoughts?

if they break, can new one's be found?  remember.. it is old!

I am going to upload a video to share the issue as well...

stay tuned.




« Last Edit: February 16, 2018, 03:55:01 AM by GaryHinshaw »
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jdcolombo

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Max Magliaro where are you . . .

John C.

mmagliaro

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Ouch.

I don't know how helpful I'm going to be. 
This is going to be a difficult and somewhat risky repair, no matter how you slice it.

I'll try to give you some "good enough", "this might work" ideas.


FIRST:
Here's my short list of things to beware of, and then some suggestions to try to fix this.
As I understand it, you have "run out" BOTH WAYS?  The edge of the driver wobbles in and out as it rotates because the driver is not pressed perpendicularly onto the axle, AND the driver rolls kind of like it's an egg shape because the axle is not centered in the wheel.

Ouch.

I wrote a whole long spew about ways to use gauge blocks, a jeweler's vise, and so on, to try to straighten this out.
If it just wobbled in and out, that might work.  But since it wobbles in and out AND up and down, I really think you need to replace the driver set.

1. Don't count on being able to find replacements unless you hunt down a whole second engine to use as a parts donor.

2. Brass engine drivers have a very tricky insulation method.  Usually, the driver center is pressed inside the outer "tire", and both are conductive.  So on ONE side, they put a microscopically thin layer of something like wax paper in there when they press the center into the tire so that the tire is insulated from the center (and the axle).   You usually cannot see, nor even be aware, that this insulating paper is in there.   This is why two brass drivers on a metal axle don't create a dead short.  But when you start bending, pressing and twisting, if you move that center in or out even a hair, or rotate it even the slightest inside that tire, there's a darn good chance you will tear that fragile insulating layer and cause a short.

SECOND: What to do to fix this?

If it was just in/out wobble, honestly... I'd try something very brute force and simple.
Roll the driver set on the workbench, use calipers or a nice metal block that is the exact spacing you want between the driver backs, to accurately spot where the widest spot in the wobble is, and then gently give the drivers a squeeze together at that spot.  Then roll and try again, iteratively chasing the wide spot around until you get it down to where it's acceptable.  Then put a drop of red Loctite at the axle/driver joint and hope it will get into any gap, harden up, and keep the wheel from drifting cock-eyed again.

But since it also wobbles up and down - forget it.  Either the center hub hole is egg-shaped, or the hub is bent,
or the whole driver center is bent, or the axle itself is bent.

====
Can you measure the driver with calipers?  In HO Scale, there are actually quite a few places to buy nice replacement steam loco drivers. 

Try here:
http://greenwayproducts.com/greenway-products/wheel-sets-trucks-and-drivers/replacement-drive-wheels/page-4/

They make ready-made driver SETS - drivers already mounted on an axle with bearings and a gear.
They are very vague on the size of the bearing blocks and gear, so I would measure your gear diameter with calipers and count the number of teeth, as well as measure the driver diameter, and then just call them to see if they have an exact match for what you need.

Honestly... that's would be my first approach.

=========
Grrrrr.... How I wish somebody made such a variety of steam locomotive parts like this for N Scale!

seusscaboose

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Thanks John and Max

Stand by for video in next 48 hours
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Point353

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Have you considered leaving the Hallmark brass model as-is, just for display, and buying a Bachmann or BLI 2-8-0 for use as a runner?
Or, could the Hallmark be repowered using the mechanism from either a Bachmann or BLI loco?

peteski

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I can't really add much to what Max wrote.  But I wonder if the up/down motion is not really there - just  the side-to-side wobble of the wheel makes it look like the axle is not centered in the driver?  A video should be helpful in seeing the problem.  It is hard to believe that a brass model would be made this badly.  The side to side wobble could be caused by physical damage, but the off-center axle would have to come from the factory that way.
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mmagliaro

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I can't really add much to what Max wrote.  But I wonder if the up/down motion is not really there - just  the side-to-side wobble of the wheel makes it look like the axle is not centered in the driver?  A video should be helpful in seeing the problem.  It is hard to believe that a brass model would be made this badly.  The side to side wobble could be caused by physical damage, but the off-center axle would have to come from the factory that way.

I also really want to see video to make a better assessment of this.  But my guess is the problem certainly didn't come from the factory.  The engine was probably dropped at some point, or somebody tried to do "repairs" on it and bent up the wheel.
You do have a point about the wobble.  In/out wobble could be so bad that it will make the engine dip up and down.

peteski

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I also really want to see video to make a better assessment of this.  But my guess is the problem certainly didn't come from the factory.  The engine was probably dropped at some point, or somebody tried to do "repairs" on it and bent up the wheel.
You do have a point about the wobble.  In/out wobble could be so bad that it will make the engine dip up and down.

Yes, I can't imagine anything that could damage the wheel (after initial assembly) in such a way to cause the axle to become eccentric to the driver. Especially when the axle and the driver parts are all-metal.
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seusscaboose

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thanks guys....

working on the video...

"I have a train full of basements"

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mmagliaro

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thanks guys....

working on the video...

Thanks.  Get CLOSE... and run the engine as slow as you possibly can.

peteski

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I'm also curious about the "worm wheel problem".  Could both issues be related?
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mmagliaro

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I'm also curious about the "worm wheel problem".  Could both issues be related?

There's a worm wheel problem?   I reread his post.  It's just that the driver with the gear on it (the worm wheel)
is the same one with the wobbly drivers.  I think the whole problem is just that driver set has wobbly wheels.  I don't think
there is anything wrong with the gear.

seusscaboose

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video as promised... apologies for the delay

thoughts?

"I have a train full of basements"

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mmagliaro

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The engine is running way too fast, and the video is not close enough, to really tell what's going on.

But here's my best guess.

It could be wheels not perpendicular to the axle on that geared driver, but I think it much more likely that it is a quartering error jerking the wheel back and forth, up and down. 

Because...
There is clearly a lot of slop in the bearings on that geared wheel.
If you'll notice, one thing you can see is that the two drivers on that same axle wobble in UNISON.  When the top of the right driver edge drifts outward, the left driver edge drifts INWARD.   That really looks more like the whole axle is simply wobbling in the bearings, more than the driver not being perpendicular on the shaft.

And this is a common malady of brass steam.  They sometimes leave lots of slop in there to help the wheels make it around in spite of quartering problems.

Try this...
Pull all the rods off and run it just on the geared driver.  See if it still wobbles like that.  I bet it doesn't.

If it doesn't, one thing you can do is shim the play out of the bearings on that geared driver.   I do this with tiny strips of .001" or .002" thick brass.  K&S sells a sample pack that has little sheets of .001, .002, .003 and .005" thick brass.   You can cut a tiny strip with an Xacto and a straight edge, and then wrap it around the forward or rear edge of the frame where the bearing slides in.  When the bearing is in, it will keep the strip from coming out.  It takes some experimentation to find just the right thickness to get rid of all that play, but still not jam the bearing in there so tight that you can't get it in or out, or make it so it can't "float" a little.

And you will have to try to forward and then the rear edge of the bearing slot with the shim to see which side works best.  Remember, the shim is going to force the wheel to stay a little more forward or rearward, which may help the quartering issue or make it worse.

And finally, you may need to shim both sides of that axle, and you may been to shim them on opposite edges of the pocket.  It takes patience and experimentation to see what's going on.

I have fixed brass steam with this wobble/bearing problem before.  The Key/Yulim 4-8-4 comes to mind.  It typically has at least one driver that wants to "hunt" back and forth in the pocket and shims will tighten that right up.



eja

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Max,

Your insight is amazing !

And this type of problem is why I do not run steam (as much I would like to).