Best Of SP&S 4-6-2 #626 Project

[mmagliaro]

Well, here's what's going on with my latest locomotive project.  This time it is a Pacific.  SP&S #626, class H-1.
There were 7 of these, all handed down from the GN and they were all converted from GN 10 wheeler class H-7's originally.
#626 is the only one to sport a Vanderbilt tender.

I'm just putting a whole dump of step-by-step photos in this one post to illustrate where I'm at.  Folks with no interest in steam,
in kitbashing (or in me!), feel free to click your "back" button now

First, here's a shot of the prototype:



My model will be built from a Kato C55 with a kitbashed Spectrum Vandy tender.

This whole first series of photos shows the frame grinding, motor replacement, and swapping the Kato C55 valve gear for
that of a Kato Mikado, which is a pretty close match to the SP&S. ALSO, this section shows how I moved the
front driver back just a tiny bit, because the prototype actually does not have even driver spacing.  #1 and #2 are
6 scale inches closer together than #2,#3.

[peteski]

All those photos took a while to load!

Excellent progress report on your new project.   That is a very ingenious, yet very simple and basic method you used to move the front driver back.  I like it!

Another Faulhaber motor with a gearbox: Looks like Mr. Motorman is making some money on you. 

I have a question: Do you think (or can you actually notice) that the very soft coupler spring cushioning the motor is really making any difference?

Your motor mounting bracket looks quite sturdy.  To me that seems a bit over-engineered. I think that I would have tried to just mount the motor on a bracket made from thinner material, solidly bolted to the chassis. The bracket itself would then be flexible enough to provide some springiness.  I think that I woudl have alos just cut off the stub off the left side of the chassis and screwed the motor bracket solidly to the right chassis half.  That way there would not be all of those styrene shims or nylon screws to worry about.

[Chris333]

You sure can pick unique prototypes!

Would you happen to have a photo of the original GN 4-6-0? It must have been quite a re-build.

[mmagliaro]

Here's a link to a photo of a GN E-14 (these were the 4-6-0's that were rebuilt
into GN H-5 and H-7).  Some of the H-7's were handed down to SP&S (and were called "H-1" on that road).

Heh, I actually am not trying for "weird" prototypes.   But on the SP&S, there seem to be a number of them.
And #626 is a pretty engine, I think.

Peteski,
That L bracket... to tell you the truth, I have no idea where it came from.  I got this engine, and the motor and
gearhead, from motorman.  He doesn't know where the bracket came from either, but it was mysteriously in
the box of stuff he sent me, so I used it. 

As for that spring, I do know this.  The engine runs a lot better with the motor floating a little
(screws not completely tight).  And I didn't like the idea of it just wobbling around in space.  The light spring
keeps it from doing that.  It is "semi rigid" that way.   As for the shims, they really aren't a bother.  And to be honest,
it's a lot easier to get the worm mesh correct that way.  One can just fiddle with it, insert another .010 or .005, see
how it runs, and so on, and then when you get it really good, just make up a final shim, put it in there, and you're done.

This thing will start and run at 0.9 volts now, with all the rods and drivers connected, running on test rollers on my workbench.
So I'm not about to mess with it!

[peteski]

Peteski,
That L bracket... to tell you the truth, I have no idea where it came from.  I got this engine, and the motor and
gearhead, from motorman.  He doesn't know where the bracket came from either, but it was mysteriously in
the box of stuff he sent me, so I used it. 

This thing will start and run at 0.9 volts now, with all the rods and drivers connected, running on test rollers on my workbench.
So I'm not about to mess with it!

Right, at this point I wouldn't mess with it either!  But also remember that the 4:1 gearbox provides lots of torque on its output shaft with 4 times less strain on the motor.  I'm not really surprised that it runs on 0.9V.

I would also like to confirm if I understand the construction correctly.  The worm acts as a coupling between the gearbox shaft and the flywheel shaft?  Was the gearbox shaft the correct diameter to fit the worm or did you have to ream the worm hole?  Is is glued in or press-fit?

[Lemosteam]

Max, that's exactly what I did to push my bachmann 4-6-0 rear driver back, but I had to make custom siderods.  Are you using the OEM flex coupler on the front of the gearhead?  That wouls allow for any misalignment between the worm gear axis and the gearhead axis...  How did you lengthen the worm shaft for the flywheel?

Your work is so amazing.

Between you and Jason, I give up! 

[mmagliaro]

Peteski,  True about the gearhead, but I can tell you that when the gear mesh isn't good, or there's binding anywhere,
it won't run at that low a voltage (even with the powerful gearhead).  In fact, it won't run as well in reverse (about 1.3v),
a problem which I am still working on. Although I am probably being nitpicky, as it runs mighty slow at 1.3v.

EDIT:
The worm was NOT bored out, as I posted earlier.  The gearhead on this one has a 1.5mm shaft.
There is no flex coupler.  The worm is mounted directly
on the gearhead shaft, and there is a 1.5mm shaft coming out the other side of the worm, through one of
the original worm-carrier bearings, to the flywheel which hangs on the end of it.   In retrospect, it might have
been a better design to put a single long 1.5mm shaft through both worm carrier bearings, with the worm in there
as per the original engine, with the flywheel hanging on the end, and just use the original flex coupling.  But that would require
pushing the motor back 1/4", maybe even more.  It probably would not fit.

[Nick Lorusso]

Looks like it is going to be a nice project. I'm not a steam fan but a SP&S fan so I'll be watching this thread.

Nick

[superturbine]

Max,
Looks like a great build and one that will provide modifications to this mech to build numerous other locomotives.

As far as taking things slowly... I agree with you, but then again I LIKE TO STRIKE WHILE THE METALS HOT!!

Good start!

BTW Thanks Lemo!

[mmagliaro]

Jason, I'll NEVER churn out engines as fast as you.  I don't know how you do it!

BTW, moving the drivers turned out to be not nearly as awful as it first seemed.   Using a caliper, I could
accurately measure the width of the frame slot.  Then, I just kept carefully filing that back surface,  measuring
often, on both sides, at the bottom of the slot and the top, until I got it exactly .015" wider than when I started,
all the way around.
It is supposed to be 6 scale inches closer than the other two drivers.  But that's .0375" in N Scale.  There's no  way
our flanges will allow driver spacing that close. 

I really wanted to do the driver spacing.  As slight as it is, you can still see on my model that #1,#2 are closer together,
and it's kind of a spotting feature.   When I was looking at lots of prototype photos, I immediately noticed it.
I think that it is a by-product of these things being rebuilt from 4-6-0's that had the rear drivers set back
even more.  I can't remember where I read that, unfortunately.   But it ties the model in to a little bit of
railroad history, which I like.

[RWCJr]

Thanks for taking the time to take lots of pics, and the text to describe the action. Going to enjoy watching this thread. Robert

[mmagliaro]

Thanks for taking the time to take lots of pics, and the text to describe the action. Going to enjoy watching this thread. Robert

THANKS!  I know there are a lot and they take time to load, but this time, I'm trying to religiously photograph everything
with good light on a white background and post them all at exactly the same width so the project is easy to follow.

[dnhouston]

Wow Max, nice work and great pics.  Eagerly awaiting more progress on this.

[jmlaboda]

A 4-6-0 rebuilt to 4-6-2... intriguing!!!  Did any other roads do this?

[mmagliaro]

Quick operational improvement.  Recall that in reverse, it doesn't do as well as in forward.  I finally figured out that a shim
under the pillow block does the trick. The way I have this set up, with only 1 pillow block instead of the original 2,
the whole motor/work/shaft assembly kind of wants to "pivot" up and down with that pillow block being the pivot point.
It's possible to work the shims under the motor more, I suppose, to keep the motor from dropping too low.  But I worked
that angle for quite a while and had no more success.   A shim under the pillow block is a lot easier to control and get right.
A .005" shim in that location pretty darn well keeps the worm up .005" more,
and that seems to be the ticket for ultra-smooth, ultra-uniform motion in both directions, and both under 1 volt now.

I hope this doesn't bore folks too much.  I just want to chronicle the journey from "box of scrap parts" to "finished model".
None of us knows quite what's in store, and that's all part of the fun.