Re: [HOn3] Re: What Will You Pay For a 4-4-0? (Was: ERAs, Blackstone class ...
- On Oct 31, 2006, at 9:29 PM, zul36@... wrote:
> In a message dated 10/31/2006 7:20:27 PM Pacific Standard Time,I'll bet a second Athabaska kit, released after producing the first
> Almost ANYTHING can be built or modified AND made to run operationally
> with SKILL, time, GOOD EQUIPMENT AND TOOLS, as well as desire. But
> these processes don't translate well to RTR or even to the 'typical'
> modeler. I will agree that HOn3 does not have 'typical' modelers and
> the skills levels are several deviations above the hobby as a whole -
> but I would challenge anyone who believes a manufacturer could adopt
> these principles and produce RTR or even 'drop together' kits at a
> price that would attract those who would not or could not build it
> themselves. Even a kit like the Athabaska would be a major tooling
> effort (CAD for the etchings - trial fits and rework) and that project
> hasn't shown a particular success in terms of actual models completed.
> Very well said!!!
one, would have much easier to build construction.
Best to ya'
Milwaukee Wi, USA
> From: Boone Morrison <boone@...>Boone
> As usual, you are right on top of the key issue. The balance of a model
> 4-4-0 is a very tricky thing - especially that of sufficient weight on
> the lead truck. .....
> This is a very basic mechanical issue that is just not that easy to
> solve in HOn3...and possibly in On3 as well...the models simply are not
> heavy enough to replicate the original arrangement.
I see that Andy has already provided web sites where appropriate
techniques are documented by the people who have actually done this sort
I see no need for springing in HOn3, except perhaps for centering lead
and trailing trucks. Mechanical analysis shows that driver springing
with deformable springs, as opposed to the rigid springing used in
commercial HOn3 models, will produce very tippy locomotives. This is
due to the longitudinal forces/reactions applied at the couplings.
Jim Vale actually tried soft springing once, and got just that result.
I think some form of equalization or compensation, is needed. The
springy beam techniques advocated by some of the CLAG authors may
provide a usable path for combining compensation with springing to get a
buildable equivalent to North American style prototype equalization.
But simple compensation should suffice for a model 4-4-0.
The prototype 4-4-0 rode well because about 1/3 of its weight was on the
truck and about 1/3 on each driving axle. The rear end is actually
supported on equalizer pivots centered midway between the drivers on each
side. The springing cushioned the load on the axle boxes, but had nothing
to do with distributing that load. So almost everything above the axle
boxes is carried on the two equalizer pivots and the truck center plate,
giving a stable 3-point suspension.
For a model 4-4-0, one need only provide a slotted frame similar to what
is now used for sprung locomotives, with a simple beam equalizer on each
side to load the driver bearings. That will put constant weight on all
four driving axles, which a rigid frame can rarely do, while allowing
the front end to follow the truck's vertical motion. I would use a wide
flat fixed loading plate under the saddle, with a small center plate on
the truck, to keep the loading centered on the truck. With this the
front support point moves laterally with the truck, but no overturning
forces are applied to the truck. This lateral motion should not be a
problems, since the locomotive's center of mass will be back near the
leading driver, and thus stays well within the stability triangle
defined by the support points.
The truck needs some allowance for side motion, with a light
semi-constant resistance centering spring. Suitable springs are
available from Kadee. The drivers will need significant side play, to
get around our corners with without excessive truck side motion. This
implies an axle hung gearbox, of which several suitable ones are
For such small locomotives, I would advocate a tender drive, with the
locomotive weighted as much as mechanical clearances allow. This
requires a three point suspension for the tender, to prevent visible
shaking due to the motor's torque reaction against the drive shaft. It
may be well to use a double reduction gearbox, since this reduces the
motor torque. But proper three-point tender suspension makes this an
option rather than a requirement. For DCC, it may be necessary to mount
the motor off center in the tender, to fit the decoder in. For
DCC/sound, I think we must wait for N-scale steam decoders.
>the motor off center in the tender, to fit the decoder in. ForWhy wait? DCC decoders are available in N and Z scale, I'm sure one would
>DCC/sound, I think we must wait for N-scale steam decoders.
fit in an HO scale tender. Tom Knapp has a sound equipped K-something or
other in Nn3. Sound and DCC are already here.
Larry P. Card
Find a local pizza place, music store, museum and more�then map the best
> From: Boone Morrison <boone@...>Boone, Boone ... Where did you think I was comming from?
> Wow!!! Thanks for sharing that....it is an amazing effort and worth
> concentrated study. Clearly, this fellow knows the subject and has
> addressed a host of the problems beautifully.
> John Stutz - check this one out...it is really great stuff and very
> well thought through.
I didn't think this stuff up myself.
Mike Sharman published his original book on OO scale model compensation
about 40 years ago. I think I got my copy in 1971. These approaches
have been a long time in development, are well thought out, and
throughly tested. But they were not invented here, and we are spoiled
rotten for locomotive construction, by what the importers could get get
for us from Asia.
For equally well thought out ideas on locomotive construction, see the
books by Ian Rice, published by Wild Swan. He has one on etched
locomotive kits, one on cast kits in tin based white metal, and one on
etched locomotive chassies construction that is worth its weight in
- The CLAG site (Central London Area Group) is state of the art P4 and S4
thinking. It represents Mike Sharman plus 20 more years of experience
and ongoing ideas. I'm an overseas member and one of the very many
co-operating contributors to the suspension digest.
Iain Rice however traditionally does things the earlier "UK craftsman"
way, using the lowest possible cost, hand made stuff and tries to get
away without using even simple precision tools, when they are really
necessary - See the Roque Bluffs Article in MR where he using wheelsets
instead of inexpensive feeler gauges for the flangeway settings. (and
the pictues of the awful rail joints). Then complains at the end his
stuff isn't reliable! ;)
The springy beams (Ted Scannell) are really equalization bars with a
little soft springing added. They are extremely non-linear when slightly
off center and so stop the rocking you'd get otherwise. Simple but very
effective. A loco so fitted effectively tied performance-wise with an
optimized and much more complicated sharman chassis when officially
tested by the S4 Society only a few years ago. And locos with equalized
suspension pick-up more reliably and pull far heavier loads without
slip compared to rigid suspension. We already have prototypes for
"drop-in" modification of Athearn and many P2000 diesel trucks.
The "Smoooth Riders" on the P:87 site do similar things for box cars
(and diesels). A lot of solid and advanced engineering (zero friction,
precision knife edge pivots and limited acting throw) squeezed into a
very simple but effective solution. What's being designed for P:87 is
actually also perfectly good as upgrades for really improving regular
HO. But we are using advanced factory made precision parts that save all
the craftsmanship, but cost much less to use. And can be quickly and
easily installed by people who have only the normal model railroader
skills and no specialized precision tools.
We co-operate all the time. That's the new proto-scale philosophy there
and here. And we are implementing more and more of it every year.
Duh.... I guess I am really stuck in Paradise here....not run into
that suspension material, though I do have
the Ian Rice books - as you say, a real treasure of information. Now
I got an understanding of even
more of what the Brits are doing...
On Nov 1, 2006, at 5:10 PM, John Stutz wrote:
> > From: Boone Morrison <boone@...>
> > Andy:
> > Wow!!! Thanks for sharing that....it is an amazing effort and worth
> > concentrated study. Clearly, this fellow knows the subject and has
> > addressed a host of the problems beautifully.
> > John Stutz - check this one out...it is really great stuff and very
> > well thought through.
> Boone, Boone ... Where did you think I was comming from?
> I didn't think this stuff up myself.
> Mike Sharman published his original book on OO scale model
> about 40 years ago. I think I got my copy in 1971. These approaches
> have been a long time in development, are well thought out, and
> throughly tested. But they were not invented here, and we are spoiled
> rotten for locomotive construction, by what the importers could get
> for us from Asia.
> For equally well thought out ideas on locomotive construction, see the
> books by Ian Rice, published by Wild Swan. He has one on etched
> locomotive kits, one on cast kits in tin based white metal, and one on
> etched locomotive chassies construction that is worth its weight in
> brass models.
> John Stutz
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