Topics

Sprung Trucks


Justin Kahn
 

Following this thread through several messages, I have to say I have always preferred sprung trucks, even though most springing is too stiff to actually work in smaller scales (it is more likely to work in O scale, but I am not sure I want to weight freight cars enough to accomplish the effect). It may not be entirely rational, but I began model railroading when sprung trucks were a considerable improvement over the low-relief cast sideframes previous available, and as my sartorial tastes were established in college, never to change much since, so my preference has always been for sprung trucks wherever possible.
As for fabricating one's own springs from craft-store wire, isn't most of that florist wire, which tends to be quite soft? Most discussions of winding springs start with springy wire. Having said all that, I should pass on that San Juan, which makes the nicest mass-market (or what passes for mass-market in O scale, especially relative to brass) trucks, and in a reasonable selection (Andrews, archbar, T-section Bettendorf, regular "Bettendorf"/AAR, Vulcan) with full brake-gear detail, has gone from sprung trucks with working wire springs to a cast-plastic spring, which is much closer to the heavy-cross-section of the prototype, but compresses only enough to be inserted between the bolster and springplank and is there primarily for appearance rather than operation. San Juan also makes a scale-size, manually-operated coupler in engineering plastic, but Gene Deimling can tell you more about those. I use the standard Kadee O scale coupler, and the only modifications or variations Kadee has done to them since they were first introduced was a special short-shank application and a few years ago casting them in red and brown colors (for extra cost)--just too small a market to invest in R&D for, I suppose.

Jace Kahn, General Manager
Ceres and Canisteo RR Co.



That's fine - then just make them look like real springs! And thanks for the kind words!

Pat Wider

--- In STMFC@yahoogroups.com, "S. Busch" <SCSBusch@W...> wrote:

Pat Wider!

When I cut my teeth in model railroading, American Flyer had chrome
plated
journal boxes on sheet steel sideframe trucks. The first time I ever
saw
real looking truck they were HO sprung Varneys or Athearns or something.
Heck, even those ugly looking Silver Streak trucks looked good.

So, there you go. I have never quite recovered, and still prefer real
springs.
Steve Busch
Duncan, SC

Yes, I vote for :

A USRA STYLE ANDREWS FREIGHT CAR TRUCK

- sprung, of course. Please, please, please ---
Why sprung? The toy cars aren't heavy enough to compress the springs
anyway and they
don't equalize so why bother? They also don't roll as well as they
could.
I hate HO
"sprung" trucks. And while I'm at it Mr. Kadee, please replace those
spider-web springs
with something more substantial. I hate looking through the spring
groups
and seeing the
daylight (layout lighting?) coming through. It's blinding. Jack
Spencer
rolls his own springs
out of heavier wire and they look great! Other people use brass loco
driver springs. In
days of old when knights were bold and Central Valley made trucks with
concentric
wheels, their truck springs looked better as well. Phosphor bronze I
think. Why can't Kadee
make a similar improvement to the appearance of their trucks?
Continuous
improvement -
that keeps companies in business.

Sorry but this a sore spot with me.

Pat Wider

Pat, I was at Michael's (a craft store) the other day and noticed
they have a wide selection of small gage wire on spools that may
be perfect for making non-functional replacement springs. I got
some for making baled-wire loads for gondolas. They stock it in
the bead jewelry section.

I agree I hate the truck springs and think the Kadees roll badly,
but they're also great looking trucks! I toss the Kadee wheels
and replace with Reboxx, which improves them considerably in
both rolling quality and appearance. Step 2 will be to replace
the springs.

Tim O'Connor
_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar � get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/


proto48er
 

The following discussion is "O" scale only, because I have never had
any HO.

Couplers:
I obsessed over the scale coupler problem for years in "O" scale -
did not like the appearance of Kadees at all, but did not like the
plastic or brass dummy couplers common to "O" because, although they
looked good, they did not operate - you had to pick the car up to
uncouple.

PSC made some "operating" couplers in brass kit form, but they did
not operate reliably and were hard to build up. PFM also made some
nice looking brass couplers which operated well and reliably, but
they were discontinued (I think - could not ever locate more of
them). They had spring-operated knuckles. I had experimented with
early Clouser couplers - a nice scale appearance (actually a
traction coupler or an early type D coupler), but they were hard to
assemble when first brought out by Bill Clouser in the late 1960's.
The castings were rough - it took me about one hour to assemble one
pair of them with tedious filing. This cleanup had to be done,
otherwise, they would not operate.

Then, in the mid-1980's, Chicagoland Hobbies in Chicago had some
Clouser couplers that were very nicely cast, not rough castings like
the 1969 Clousers. It only took 10 minutes to assemble a pair, and
the operation was superior. I was sold on them on the spot!
Contacted Clouser and bought 400 pair (in "O" scale, things have a
very bad habit of disappearing when the manufacturer decides to
discontinue them - you have to get them while you can). Best money
I ever spent!! They operate flawlessly, but do not uncouple
automatically - you have to use a wand or install (and MAINTAIN)
operating cut levers. Cut levers work great on passenger cars with
diaphragms.

Draft Gear:
The next problem was what draft gear to use. I created a design
similar to a Waugh draft gear on the prototype, and used it as a
draft gear/coupler centering device. It is built up from brass,
only uses a single spring, and consists of 7 parts. It is simple
and durable. In "O" scale, part of the function of the draft gear
is to protect your expensive brass car from damage occasioned by a
sudden stop - like running the loco into a dead block with a heavy
train. My draft gear consists of two channels, each 1/2" long, with
the outer one being 1/4" X 1/4" in size, and the other being smaller
so as to fit snugly inside the first. This smaller channel has two
slots cut straight across it, and two small pieces of flat 0.050"
brass fit in them, but are just short of touching the walls of the
outer channel. A spring is placed between the brass pieces to press
them against the sides of the two slots. A bent 0.030" brass strip
C forms a yoke which slides over and under the spring/brass piece
assembly. At the end of this yoke, a hole is drilled to mount the
coupler.

First, here's how it works: When you push the coupler into the
striker plate, the shank pushes up against the front brass piece,
which, in turn, pushes the spring. The first brass piece moves
inward until it hits the other side of the front slot. If you make
the slot so that this motion is a scale 2-3/4", you will duplicate
the prototype travel of a standard freight car draft gear of the
1940's. If you pull on the coupler, the brass yoke pulls the rear
brass piece forward until it hits the front of the rear slot. There
is a mild centering action with this setup - the spring resting
length is longer than the two brass pieces installed in the slots,
so there is pressure on the coupler shank if it is done correctly.
The coupler shank has to be cut off square and the pivot hole
drilled precisely the correct distance from the cut off end for good
centering action without any slack.

This is designed to be used with scale striker plates of various
designs. The striker plates are soldered on the end sills first.
Then the coupler/brass yoke/spring/two pieces of brass are assembled
next. The larger channel is soldered to the floor of the car.
Then, the smaller channel with the two slots is placed upside down
in the larger channel, with the one brass piece in each slot. The
inner channel is moveable at this point, so it can be adjusted to
provide the 3" of clearance between the horn of the coupler and the
front of the striker plate. Then the channels are spot soldered
together. It took longer to write this than it does to finish one
freight car.

How do you make the striker plates?? Make them out of styrene for
your specific car, then have them sacrificially cast in brass! If
you are really anal, you can also cast the outer channel with dummy
details of the prototype draft gear, but you will have to mill it
smooth or the brass pieces inside will not slide correctly.

The result is a true prototype action draft gear! It is really neat
to see the cars bunch up slack on the downhill, and strech it out on
the uphill grade. The prototype draft gear acts the same way - it
resists the coupler shank being pushed in for a travel of 2-3/4",
then sets up solid. Same action when the coupler is pulled out.

The Clouser coupler is now available from Norm Buckhart (see the
Proto:48 website) and is as nice as the ones I am using. He has the
Clouser patterns and has them cast at Valley Brass & Bronze, so they
are excellent. The couplers do have a smaller shank (4" X 5") than
the prototype.

This coupler problem bothered me for a long time, but I am OK with
the above solution. The key design parameters are the spring
dimensions and spring constant, and the ability to slide one channel
inside the other so that you can accurately position the coupler
from the striker plate easily. A. T. Kott


Richard Hendrickson
 

On Oct 11, 2005, at 11:08 AM, Justin Kahn wrote:

Following this thread through several messages, I have to say I have always
preferred sprung trucks, even though most springing is too stiff to actually
work in smaller scales (it is more likely to work in O scale, but I am not
sure I want to weight freight cars enough to accomplish the effect). It may
not be entirely rational, but I began model railroading when sprung trucks
were a considerable improvement over the low-relief cast sideframes previous
available, and as my sartorial tastes were established in college, never to
change much since, so my preference has always been for sprung trucks
wherever possible.
Jace, I'm always mystified when people express a preference for sprung trucks because it seems obvious to me that the springs never actually work, even to provide a small degree of equalization, and (aside from the San Juan O scale trucks) they look AWFUL. Kadee's HO scale trucks are admirable in most respects, but seeing all that daylight through the space where there should be four or five heavy springs totally spoils their appearance. When I use Kadees, I CA pieces of black-painted styrene behind the springs, an expedient that I find greatly improves their realism. Sprung trucks may have appeared to be an admirable new development fifty years ago, but now that we have a wide variety of highly realistic non-sprung trucks, I avoid them whenever possible. (I wonder if someone could make San Juan's idea work in HO scale?)

Richard Hendrickson


Schuyler Larrabee
 

Richard Hendrickson:

Jace, I'm always mystified when people express a preference
for sprung trucks because it seems obvious to me that the
springs never actually work, even to provide a small degree
of equalization, and (aside from the San Juan O scale trucks)
they look AWFUL. Kadee's HO scale trucks are admirable in
most respects, but seeing all that daylight through the space
where there should be four or five heavy springs totally
spoils their appearance.
Richard, you and I have debated this before, somewhat. What seems to me to be your complaint is
mostly that you can see through the springs. I agree with that. But the solution isn't to have
solid trucks (because in part, equalization DOES work) but to have better looking springs, and more
of them. There is no way that molded relief on a sideframe can represent springs as well as truly
three-dimensional free-standing springs.

I wrote a few days ago that I believe there is a market for Really Fine High Quality Trucks, sprung
and equalized, with springs made of some material with a very low spring rate, that would be molded,
extruded, cast or whatever with suficient thickness so as to properly mimic prototypical springs. I
personally think that if such trucks were available, replacing the trucks that come with kit cars
would become just as much the "standard thing to do" as is/was replacing x2f's with Kadees [or
Sergents, or whatever].

SGL


jaley <jaley@...>
 

On Oct 12, 12:35am, Schuyler Larrabee wrote:
Subject: RE: [STMFC] RE: Sprung Trucks
I wrote a few days ago that I believe there is a market for Really Fine
High Quality Trucks, sprung
and equalized, with springs made of some material with a very low spring
rate, that would be molded,
extruded, cast or whatever with suficient thickness so as to properly
mimic prototypical springs.

Schuyler,

Why is equalization important? I cannot recall the last time I
have seen a derailment (on layouts owned by several other folks, including
a club) that was caused by a lack of equalization. By this, I ASSUME that
equalization prevents a truck from derailing with three wheels on the
rails, and the fourth up in the air (due to extremely bad trackwork).

Regards,

-Jeff

--
Jeff Aley jaley@pcocd2.intel.com
DPG Chipsets Product Engineering
Intel Corporation, Folsom, CA
(916) 356-3533


Richard Hendrickson
 

On Oct 11, 2005, at 9:35 PM, Schuyler Larrabee wrote:

Richard, you and I have debated this before, somewhat. What seems to
me to be your complaint is
mostly that you can see through the springs. I agree with that. But
the solution isn't to have
solid trucks (because in part, equalization DOES work) but to have
better looking springs, and more
of them. There is no way that molded relief on a sideframe can
represent springs as well as truly
three-dimensional free-standing springs.
Schuyler, I don't disagree (except that I have yet to see a sprung
truck that actually does equalize under normal operating conditions),
but given the choice between sprung trucks with see-thru truck packages
and solid sideframes with the springs molded in – which are the only
choices currently available – I'll continue to opt for the latter.

I wrote a few days ago that I believe there is a market for Really
Fine High Quality Trucks, sprung
and equalized, with springs made of some material with a very low
spring rate, that would be molded,
extruded, cast or whatever with suficient thickness so as to properly
mimic prototypical springs.
No argument here, either. But the ideal trucks you describe don't
exist, and may never exist. Meanwhile, we all have a lot of freight
cars that need trucks under them.

Richard Hendrickson


Denny Anspach <danspach@...>
 

For decades I have favored the appearance, heft, and "feel" of sprung trucks; and I felt pretty smug about the "equalizing", and that the trucks had "Real Springs". Well, this tower of belief imploded when Richard Hendrickson first pointed out to me years ago the obvious: Just how many freight trucks have just two spindly springs through which you can read the morning newspaper, if need be? Hmmm.

And, just how much weight in real HO model time would the average sprung truck actually need to actually equalize? Hmmmm (again).

Pretty good arguments, reluctantly and slowly accepted as hard to refute. The Accurail trucks began to look better.

Having said all of this, I still choose Kadee or Central Valley metal trucks for a lot of things because I admire their high quality and finish, and---- their weight. I have saved many a closed featherweight car just by using metal trucks, and the weight is right down low where it is needed. I DO improve rollability with Reboxx wheel replacements. I have not yet resorted to gluing styrene or Strathmore blinds over the backs of the springs, but I probably will start doing so.

I do like the idea of an aftermarket development of detailed moulded spring sets that could replace the springs. A caveat would have to be that the sprung trucks have to well made enough that when the replacement "set" is inserted, the side frames would actually remain square to the bolster. The real springs being replaced could allow a host of ill-fits to be effectively covered up in this regard.

Has anyone actually measured the cross sectional dimensional accuracy of the Kadee, Accurail, and Central Valley AAR trucks against the prototype?

Denny

--
Denny S. Anspach, MD
Sacramento, California


Manfred Lorenz
 

--- In STMFC@yahoogroups.com, jaley <jaley@p...> wrote:

Why is equalization important? I cannot recall the last time I
have seen a derailment (on layouts owned by several other folks,
including
a club) that was caused by a lack of equalization. By this, I ASSUME
that
equalization prevents a truck from derailing with three wheels on the
rails, and the fourth up in the air (due to extremely bad trackwork).
That would be my question too. If a truck goes over a low spot where
one wheel would be in the air it should in reality not. Why? Because
the axles have axial play in the sideframe bearings. A wheelset that is
supported only on one side will drop as far as the axle play will let
it. The limiting factor is the weight of the car. This is pushing down
at the axle tip while the rail forces up at the wheel. A lever of about
0.18" using the typical 1.015" axle length. The lever of the wheel on
the opposite, low, side will be 0.65" (track gauge). A factor of 3.5 in
favor of the wheel's weight against the 1/8th of the car's in a
perfectly leveraged truck arrangement (total flexibility). Which is not
present on most model cars. The trucks movements are restricted by the
kingpin. This affects weight distribution in reality. I don't have the
weight numbers ready (too pounderous ;-) but imagine the wheel will
follow the depressing avoiding becoming derailed. This all is only true
if not other forces interfere and cause a derailment by too much
sideforce exerted on the truck.

So my guess is that a lot of flex is not really necessary. The built in
looseness of axle play and inherently truck elasticity should be enough
under normal conditions.

Manfred