UP 4-12-2 shell

[propmeup1]

Who's the man who makes the resin shells for the UP 4-12-2 ?  Still around casting these ?

[draskouasshat]

No, he's not doing any modeling or casting at this time.

Drasko

[draskouasshat]

With a little work though, you can turn the concor S-2 boiler into a very close boiler. If you want to get really fancy, use the back half of a kato Mikado boiler and the from half of the s2. Match it up with photos and it comes together pretty easily.
The cab can use either a kato gs4 for the start or a shortened athearn challenger. The gs4 roof has a more correct arch though.

Drasko

[propmeup1]

I kind of thought so.  I been thinking about using the Concor 2-10-2 for a start. The drivers however are a scale 5.25" too small.   I do have a spare S2 and a Kato 2-8-2 shell along with a boat load of other parts and what i don't have i can make.

[JMaurer1]

Was this another one of Superturbines offerings? God I miss him and his FANTASTIC work. Step away from the motorcycles and come back home 'Turbine...

[propmeup1]

Well if bikes are his thing then I can’t blame him. I ride year round all weather but I still play trains and models.   On one hand you ride dude. On the other get cracking in new shells please.

[draskouasshat]

I used the concor mech for the last one I've been working on.

Drasko
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[Cajonpassfan]

I kind of thought so.  I been thinking about using the Concor 2-10-2 for a start. The drivers however are a scale 5.25" too small.   I do have a spare S2 and a Kato 2-8-2 shell along with a boat load of other parts and what i don't have i can make.

Well, as much as I love the UP 9000’s, the problem is our oversized flanges, especially on five and six-coupled locomotives. The more drivers, the bigger the dimensional bust.  Attempting to keep the driver size somewhat accurate just stretches the wheelbase and overall proportions of the boiler. The Con-cor 2-10-2 has an about 25’ driver wheelbase (3’ too long for a Santa Fe 2-10-2). The UP 4-12-2 driver wheelbase, with an extra driver, is 25’-8”, only 8” longer than the Con-cor 2-10-2. So adding a driver the the Con-cor loco yields a wheelbase of 31’-3”, even without adding the additional spacing between the first and second drivers like the prototype. This just forces the proportions of the loco to be way way off, imho.

I had made a feeble effort to build a 9000 4-12-2 four decades ago, and got the proportions right I think, see below,  but it forced me to use way undersized drivers off the MRC mallet. I had abandoned that project since I felt I couldn’t make the 67” drivered loco look “right” with 57” drivers.

In my opinion, the best approach to the “flange bust” is to make steam power drivers *slightly* undersize and the body *slightly* stretched, splitting the difference. This may work well for Pacifics and Hudsons, not as well for Mountains and Northerns, and even less well for 2-10-2’s and 4-12-2’s.
YMMV,
Otto K.

[peteski]

Didn't locos with such a long rigid wheelbase have blind drivers?  If so, same could be done on a model (and probably should be done so it can negotiate model-size curves).

[mmagliaro]

Didn't locos with such a long rigid wheelbase have blind drivers?  If so, same could be done on a model (and probably should be done so it can negotiate model-size curves).

Interestingly enough, when you said this and I looked it up at www.steamlocomotive.com,
I found that initially, the UP 9000 series were built with #3 and #4 blind, but they discovered this wasn't necessary to negotiate the curves where it operated, so they put flanges on those drivers.  They relied on lateral motion devices to negotiate the curves.    In practice, with 6 drivers, you're either going have to allow for a lot of lateral slop, or you would want to blind a few drivers unless you only plan on running this thing on something like a 24" curve.  I worked on a Hallmark brass 2-10-4 that could not make 20" curves, even with the center driver blind, until I ground away some of the insides of the nubs on the backs of the drivers to allow for more lateral play.  SIX drivers... hoo boy.

[randgust]

If you go back into the Atlas archives, both Verne Niner and I had Hallmark brass ATSF 4-8-4's that drove us nuts and were shelf queens due to minimum radius problems.   Verne and I were friends and put up a joint thread on how we attached the problem to make them into runners.

Both of us had equally radical approaches.   Verne was using Peco C55 flex, and actually ground the gauge wide on his curves with a tool he made to file the inner rail thinner.  I think his minimum radius was like 15", maybe more.    Mine was 11" on hidden track so I really had a problem, and I decided to actually blind both center drivers by completely taking off the flanges.

What I had to do though, was completely eliminate lateral movement on all the drivers when I did that, fore, aft, and middle.  That involved making some rather interesting nylon washers that snap-fit over the axles like lock washers to make sure nothing could move sideways.   And that was just the opposite of how the chassis was designed with deliberate lateral play on #2 and #3, but not enough to negotiate anything under 15" from what I found out.  One little kink and you were on the ground.

Both of us succeeded and had a wonderful time with the thread.   My 4-8-4 still runs just fine, and that was a real pucker moment when you make those kind of modifications to a brass mechanism where you can't undo it and you can't replace it either, just hope it works and it did.

With a fixed wheelbase that long, you're also going to have to have really 'flat' curves, which luckily I did, as you could teeter into a derailment on a hump on a curve.   Either that, or figure out how to gain a little air under the blind drivers, or equalize.... nothing good there.

So while I always admire the guys that try to do it to scale, I'm going to be equally impressed by a 4-12-2 that actually runs as a model and doesn't require 30" curves to do it.   But I'd think you'd still be stuck with probably 15", so whatever approach you do take with it, you need to test the chassis design hard before you invest a lot of effort on the project unless it's primarily for display.

I do miss Verne, he was my first great forum friend and we did get to actually meet in Arizona.   When he sold off his N scale going into On30 I got some of his work and I'm certainly glad I did.  We had a similar off-the-wall problem solving approach never taking anything too seriously and had great fun with it.   But this project was a high-water moment in violating every standard practice both of us knew.  But it still set the bar for how I approach steam, dimensional perfection is nice but one that actually runs (and doesn't derail) is better.

[Cajonpassfan]

I do miss Verne, too. He and another dear Arizona friend, Chris Lane (another amazing modeler) spent the night at our house on one of their trips to California and the three of us were like little boys running trains till wee hours of the morning. Fond memories. Chris is now gone too...
I did bid on Verne’s  passenger FT set, wanted it bad, but it went for a ridiculous amount of money to a collector in Japan I believe.
Sorry about the drift,
Otto

[superturbine]

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Takes a special kind of person to want to build a 4-12-2.... i might have a few shells left over.  I know i have rods and other parts needed to convert a mikado into the UP type.

[propmeup1]

Ok Mr. Superturbine, How do I get set up with a 4-12-2 shell and some rods ?   Thank you.  propmeup1@verizon.net if you'd like to email me.

[rodsup9000]

  I dug one of the 9000 out that I started many years ago. These were built by cutting 2 sets of Kato mike frames apart, pinned and epoxied back together using a fixture to keep them aligned and straight. The front driver is spaced to the correct dimension. The Kato mike has axle spacing of 69.5" where as the prototype is 70"  I don't think you're going to see a half of inch in N scale make much difference. The front pilot set is from a RR pacific with correct diameter wheels. Work stopped as I couldn't get the shell to look right and when Jason was making the shells, I was off messing around with the 20.3 narrow gauge stuff.

 My layout has 24" minimum radius curves and they run very well on them. The 2nd and last driver are traction drivers and I stuffed the boiler full tungsten putty.  It's been a long time since I've run any of them, but I think one will pull a 40 car freight up my 2% grades.