Equalizing process and "faking-it-out"

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thunderskunk
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Equalizing process and "faking-it-out"

Post by thunderskunk »

Hey guys,

I'm into the spring and equalizing system on my 7 1/4" Pacific design. I've found info here and there throughout the forum on why equalizing an engine is a good thing for derail prevention and tractive effort, but I still have a few questions.

What is the proper process for actually equalizing the engine? What I think I've caught is that you put all the springs you can onto the vertical equalizing bars then either remove leaf plates or material from the bars themselves until the engine is level. In Nelson's book, it sounds like you use a weight to represent the boiler on the back of the frame to balance the cylinder block, but he doesn't go very in depth.

Somewhat in another direction; Are there any good examples of folks who fake the leaf springs and use coil springs on the drivers? For some reason I imagine using coil springs to be significantly easier to install, equalize, and replace over leaf springs.

I don't mind being referred to previous posts either. I simply can't find something clear-cut on the two topics.
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Mike Walsh
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Re: Equalizing process and "faking-it-out"

Post by Mike Walsh »

534 frame.jpg
Yes. The Wagner locomotives used a suspension system that used a lever in place of a leaf spring sitting atop the driver box, and utilized coil springs nestled in the frame. For reference, I am speaking of AJ Wagner and Sons -- they built 12" and 15" steam locomotives.

See attached photo. I hope it's clear enough.

-Mike
Berkman
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Re: Equalizing process and "faking-it-out"

Post by Berkman »

That setup doesn't look like it would truly equalize.
Mike Walsh
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Re: Equalizing process and "faking-it-out"

Post by Mike Walsh »

Berkman wrote: Sun Mar 25, 2018 9:40 pm That setup doesn't look like it would truly equalize.
...If you say so. Meanwhile we'll keep running it, pulling 75 passengers in a 9 car train... And on occasion, the 15 car train with 120+.

-Mike
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johnpenn74
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Re: Equalizing process and "faking-it-out"

Post by johnpenn74 »

Here are a few ideas that night help.

If you do leaf springs, the length of the leafs in the stack should have equal subdivided stepped length to the sets. This makes it so you can calculate the spring force based on the shape and material. If you have need to add leafs to add force, you do so by adding a full length leaf on the top of the stack. The formulas and such are on MITs website.

To get the right spring load you need to know the weight being applied at each journal. One way is to scale each axle. REmember though, this only works if the eqlization system is free floating. IF anything is bottomed out, binding or otherwise; then the system will not shift and not equalize.

If you really wanted to do it the long way, you could put the engine on a balance, determine you overall weight and center of mass. Then do you equalization calculations to determine the force on each spring. Then springs will be right, out of the gate.

One last thing, the journal hangers and such are not very traditional compared to US designs (leafs over the driver box) but the setup does look exactly like you would expect on any consolidation with grate over the drivers. The point being is should pivot and equalize.

JP
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RET
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Re: Equalizing process and "faking-it-out"

Post by RET »

Hi,

The equalizing system shown in Mike Walsh's picture is fairly typical of equalizing systems (it is used in Big Boy) with minor variations. Equalizing is mainly a North American development. In Britain, springs were mounted under the individual axleboxes and that was generally good enough because in Britain the track was better. North American railroads had longer distances to travel and so generally track was poorer, forcing the development of equalized springing. They even had "rails" made from flat bar spiked or screwed to wooden rails!

The equalized system of springing started with the American 4-4-0 with a 3 point suspension and developed from there. In the 4-4-0, the front truck was the lead suspension point and the pivot point of the equalizer bars between the rear axles were the two rear suspension points. Because of their suspension, the 4-4-0's could handle almost any kind of track no matter how bad it was. As locomotives got bigger, the 3 point system became much more elaborate, but the concept still stayed the same and in many locomotives, the equalizing bars even extended to the leading and/or trailing trucks.

If you look at Mike Walsh's picture, you can see the paired horizontal bars that go over and rest on the center of the axleboxes and at each end of those bars is a connecting link with springs between the link and the frame. Both the spring links and the connecting links can pivot. Because of the links, movement of one axle vertically transfers some of the load to other adjacent axles, thus smoothing out the effect of track variations.

For our models and also for full size, the wheels and axles must be able to move freely. If for any reason they can't, the engine, tender or car will derail, even on straight smooth track. When we first got Big Boy, that is exactly what would happen with the centipede tender. After freeing up the axleboxes, changing the springing, etc. now I can "sling" the tender down a 60 foot long stretch of track in the back yard. It rocks and rolls a lot, but it always stays on.

I hope this helps a bit.

Richard Trounce.
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DianneB
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Re: Equalizing process and "faking-it-out"

Post by DianneB »

I run an older LE American and the equalizing is almost a necessity! The 4-4-0 is so shy on traction that I couldn't get up-grade out of the steaming bays until I cleaned up the suspension and got it all working freely. I even added a "weight-transfer" drawbar to transfer some of the rider's weight from the tender to the back of the locomotive and THAT made a huge difference!

I am sure that on a larger engine, equalizing wouldn't be as critical.
thunderskunk
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Re: Equalizing process and "faking-it-out"

Post by thunderskunk »

Hey,

This all helps tremendously. I don't think I'll be attempting to fake the leaf springs with coils; the way you guys have explained it seems a bit less daunting. I might even try finding the center point and doing some calculations out as system balancing is an interest of mine, but it's good to know I can still play things by ear.

It's kind of funny; I'd always thought smaller engines wouldn't need to be equalized over big engines, but I've heard a few times just the opposite here. Must have picked it up from Kozo's A3 book, since his larger scale version has a more robust equalizing system.
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Harold_V
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Re: Equalizing process and "faking-it-out"

Post by Harold_V »

thunderskunk wrote: Thu Mar 29, 2018 10:16 pm It's kind of funny; I'd always thought smaller engines wouldn't need to be equalized over big engines, but I've heard a few times just the opposite here.
Heh! Equalization can spell a huge difference.
How many folks here can remember the UP Northern (now owned by Chuck Hackett) when it showed up at Train Mountain some 18 or so years ago? It had a hard time dragging itself around the track, and had to be pulled back by a Pacific (then owned by Lee Carlson). The engine, as built, had pulled well, but it had been sold upon the death of Denis Richy (the builder and owner), to a new owner, who had messed with the suspension. I'll let Chuck tell you if it pulls well, or not, now. I have no clue.

H
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Re: Equalizing process and "faking-it-out"

Post by Asteamhead »

Hello modelers,
Reading this post, I searched for some elder photos taken during the building of my class A.
As within the prototype, you will find leaf springs in combination with equalizers inside the frame
and solid bars instead of leaf springs with leaf springs(fake) as equalizing levers inside the rear frame due to lack of space.
See the drawing of the prototype, too please! Most astounding fact is the total absence of any adjusting bolts throughout the construction done by the N&W.
The worth of a working equilizing system is to be seen with all those prototype engines still in use by volunteers on rails mostly being in less than ideal conditions!
With our models it's quite the same story due to unknown layouts to be used sometimes. If you ever have the chance to run an engine with good equalizing on curved track you will feel the difference at once, believe me. Using stiff springs instead of soft coil springs helps to avoid swinging from one side to the other, which is typical for engines without an equilazing system, too.
It's worth the additional work on the frames anyway

Just my two cents
Asteamhead
Attachments
Combination of (stiff) leaf springs and solid levers will give the wheels free movement about 1/4 " up and down
Combination of (stiff) leaf springs and solid levers will give the wheels free movement about 1/4 " up and down
Just one leaf spring in combination with solid levers will result in full equalizing, too
Just one leaf spring in combination with solid levers will result in full equalizing, too
Casted levers were used instead of spring leafs due to the fat boiler's size above
Casted levers were used instead of spring leafs due to the fat boiler's size above
RET
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Re: Equalizing process and "faking-it-out"

Post by RET »

Hi,

An equalized system by itself with dummy springs is OK, but if you combine it with working springs, especially on our model tracks, a fully sprung suspension system works much better. While you can make dummy leaf springs with coil springs inside, there are two ways I know of making real working leaf springs that flex and perform just the way they should. By the way, for coil springs, the spring stiffness varies as the fourth power of the wire diameter, so small changes in diameter really change the stiffness of the spring.

If you put together a model leaf spring that is the same as full size, it will be so stiff that it wont flex at all. This is partly due to friction between the leaves, but mainly its because of the square cube law. The leaves have to be thinner, thus weaker than a scaled leaf would be.

For working leaf springs, the first method is to bend all the leaves to the same radius but put thin spacers between each leaf so when the spring is unloaded, the individual leaves don't touch each other. This way as the spring is loaded, the leaves come into play progressively. This is a necessary condition no matter how you build your spring. The second method, which I think is even better, is to make each leaf a different radius with the largest radius on the bottom and the smallest radius on the top with the longest leaf. Again as the spring is loaded, the leaves come into play progressively. The 3 1/2" gauge Boston & Albany Tanker I have uses this system with working leaf springs over the axleboxes. I can rock the engine side to side 5 degrees on either side of center and all the wheels stay on the track.

If your locomotive suspension is properly set up, for 3 1/2" gauge, you should be able to clamp a 1/8" thick piece of steel to the track and roll the locomotive over it. As each wheel rolls over the steel piece, you can see that wheel raise up and watch the suspension move and flex, but all the other wheels must stay on the track. For 7 1/4" / 7 1/2" the steel piece used should be 1/4" thick.

Hope this helps.

Richard trounce.
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johnpenn74
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Re: Equalizing process and "faking-it-out"

Post by johnpenn74 »

Equalization and Springing are two different parts of the suspension system. Bear in mind that two serve two different functions.

Equalization - like the name suggests is all about making wheel's ultimate loading of the drivers to the rail the same. This gets into some physiscs and frictional loss calculations. The long and short of it is - If the weight to the rail is not the same then you are burning up a lot of tractive effort to friction. IE the loco pulls less.

It should be noted that wheel loading (where wheel hits the rail) is not the same loading as axle loading (where the journal hits the axle) The difference is additional amount of weight that a heavy driver, main road, main journal, and heavier side rods impart on the main driver. The wheel to rail load should be the same For this reason the equalizers will not be symetrical and the leaf sets will be different on each axle. THe equalizers lack of symetry is so you can shift the weight to the lighter drivers. The different in the springs is because the shifted load on each axle will have less force pushing it down, so the spring will be less. The attached picture shows the equalizer moving the load **off** of the heavy main driver.

Springs - Remember there is only size spring (be it coil or leaf) that corresponds the physical travel of the journal in the frame and the force imparted through it by the equalization system. Its not adjustable. Granted, the reality is the available leaf thickness /material or coil size is never exact and you have to pic one size that is close based on what is in the catalog.

All bets are off ---
If your equalization system binds or bottoms out at any point then its not equalizing. This causes slipping.
If your springs are too soft then they simply crush down and become solid blocks of steel. They can't soak up the bumps. This is also what causes you to slip.


JP
Attachments
equalizer gwr.png
John Pennington

Logging meets that actually move logs

Project
2 Mich-Cal Shays
Allen 4-4-0 Narrow Gauge Conversion
Two Reading A5a Camelback 0-4-0
USRA 0-6-0
Clishay
4 Western Wheeled Scraper NG Dump Cars
N&W 4-8-2
ICM 2-10-2
4 Modern Stake Cars
L&N Caboose
4 Big Four Conversion Gondolas

Like I'm actually gonna build all this stuff :-P
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