# where does one get side rods?



## cape cod Todd (Jan 3, 2008)

Hello All
I am moving forward with a project that I started over 2 years ago. I have a motor block, I don't know the manufacturer. I want to build a little gas/diesel narrow gauge shunter that I rode behind on a bog train in Ireland. Question is where do I get the side rods for my build. Right now my block is 4 very shiny chrome wheels with axles that poke out about 3/16 or so. How do I attach side rods? 
What do you guys suggest? 
Thanks in advance for answers. 
Todd


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## DKRickman (Mar 25, 2008)

You could make them yourself. Do you want an inside or outside frame? 

Inside frame is easy. Cut the stub axles off and drill a hole in each wheel EXACTLY the same distance from the axle. 

Outside frame is almost as easy, if not easier. Make 4 counterweights (solder 4 pieces of brass together and gang-drill, if you have a drill press), again with the crank pin the same distance from the axle, and use some brass tube which fits over the sub axles as the outside axle. 

The rods are simple to make, but you need to make sure that the holes are spaced exactly the same as the axles in your motor block. Remember that they're really nothing mor than a sheet of metal or plastic with two holes in it - everything else is cosmetic. 

If you're going to use the rods to transmit power, fit is pretty important. It's also important that you get the wheels quartered properly - it's not as critical that they're exactly at 90 degrees as that all axles are quartered the same. If you're not using the rods to transmit power, everything can be made to fit a bit more loosely.


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## Torby (Jan 2, 2008)

I think I'd look at the K&S rack at the local hardware store.


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## John J (Dec 29, 2007)

You could talk to Barry of Barry's big Trains. He is a member here.


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## SE18 (Feb 21, 2008)

actually, I had the same question as the poster. 

Kenneth explains the procedure, but my question is, should the placement be the same on both sides of the locomotive, or does it matter? 

Also, perhaps someone who has done the procedure could post their work


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## DKRickman (Mar 25, 2008)

Posted By SE18 on 11 Jan 2010 10:45 AM 
should the placement be the same on both sides of the locomotive, or does it matter?


By placement, I assume you are referring to the angular location of the crankpin? If so, one side should lead the other (it doesn't really matter which side) by 90 degrees. It's less important if both axles are powered internally, but quartering does matter if you're using the rods to drive one or more axles.

There are two reasons for quartering. On steam locos, it ensures that one piston is at the end of the stroke while the other is at top dead center. The other reason, and the only reason on a diesel or electric, is that it prevents the wheels from binding.

If you imagine a pair of axles running freely in a frame, with only one side rod connecting the wheels, you can see that the wheels will bind up pretty easily. The same is true if you have two side rods exactly 190 degrees apart, because they both reach the end of their travel at the same time. Having two or more rods at anything other than 180 or 360 degrees will ensure that the wheels must continue to run in the same direction. 90 degrees is best, because it is exactly midway between the extremes, but anything reasonably close will work.


From the above, you can see why quartering would not be as important with axles powered internally - they're already forced to run together. In my opinion, it's better to go ahead and quarter the drivers anyway, just in case, and to satisfy rivet counting purists like me.

Hope that helps.


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## BarrysBigTrains (Sep 4, 2008)

As a manufacturer, I have siderods made primarily in one of two ways; they are cast or are laser cut in stainless steel.

From those two forms I can make siderods using the ends of one or the other and bridging the gap with rectangular brass tube.

The standard spacing for the stock siderods is 2.1" axle to axle, or the standard Bachmann Big Hauler axle to axle spacing of 2.67"

My custom wheels, staniless tires and brass centers are drilled for quartering in drill jigs, for uniform location of the rod pins.

My custom wheels are 2" copies of the Bachmann Big Hauler driver with 1/16" added to the counterweight.

The 1 3/4" brass and stainless wheels are of the C-16 wheel in 20.3. The tires in both cases are stainless steel, needed especially for running on the 
currently popular stainless steel rail.

Barry - BBT


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## SE18 (Feb 21, 2008)

Thanks, Kenneth, I'm primarily interested in making siderods for early diesel critters. 

You said: "It's less important if both axles are powered internally, but quartering does matter if you're using the rods to drive one or more axles." 

I'm not powering both axles and I'm not using the rods to drive 1 or more axles. I have my motor connected (via gear) to one axle and have no need to drive the other axle as the critter chugs along just fine. So this is more for cosmetic effect. 

Out of curiosity, if I were to install the rods, would the other axle be driven anyway by the powered axle? 

BTW, I always wondered what quartering meant and now I learned something. Quartering means a quarter turn placement of the driving rod on the wheel either fore or aft in relation to the one on the other side. 

Of course, if someone were to post a picture of each side of the locomotive, that would illustrate. 

Much thanks 

Dave


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## SE18 (Feb 21, 2008)

OK, here's something I'd like to build, an 0-6-0 (see link). Does the principal of quartering and placement still apply on these? I'd also like to do some 0-4-0s. 

Notice in the photo that the rods appear to be attached to cams. I notice that in the master builder section of this forum, people are mostly scratchbuilding steam locomotives. I'm more inclined to diesel or gas critters. 


http://1.bp.blogspot.com/_kPNB0fGN7...-Train.jpg


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## lownote (Jan 3, 2008)

Quartering is pretty simple. Each driving wheel of a loco has a hole for mounting the connecting rod. On the right side, set the wheels so that all the holes are at 6 o'clock. On the left side, set the wheels so that all the holes are at either three or nine o'clock. It was necessary with steam engines because they were piston driven. If the train stopped with both pistons all the way out, it would not be able to move. Quartering insured that the two pistons were never in the same fully-extended position at the same time.

On a diesel, the connecting rods don't need to be quartered. 


In that picture, the things that look like cams are counterweights--the weight of the connecting rod and attachment throws the wheel out of balance. Counterweights keep the whole thing balanced. They have them on steam engines as well, but they usually look different.


Why would a gas mechanical like that have connecting rods? Probably only one set of wheels is driven by the motor. But you would get better track adhesion and pulling power and less track wear if you spread the weight, and the driving force, over more wheels


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## SE18 (Feb 21, 2008)

Thanks, 

I'm using spoked wheels so I probably would have to drill a hole thru one of the spokes to attach the rod via a fastener. Is there any recommended measure how far down the spoke the rods need to be attached?


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## Pete Thornton (Jan 2, 2008)

rods appear to be attached to cams. 
Dave, 

Those 'cams' are counter weights. As the wheels rotate, the side rods are being thrown outwards by centripetal force so the wheel will try and wobble - just like an out-of-balance car wheel or ceiling fan. The balance weight counters that wobble - like adding weights on your car wheel to balance it. 

All locomotives that have side rods have counter-balance weights. You may not have noticed them on a steam engine, but they are opposite the crank pin for the side rod. See below - Bachmann Big Hauler 4-6-0 wheels and rods. 










Does the principal of quartering and placement still apply on these? 
Yes. It applies on all locomotives, steam, diesel or electric, that do not have all axles powered by separate internal gears/motors. 

Out of curiosity, if I were to install the rods, would the other axle be driven anyway by the powered axle? 
Dave, Yes again, and you *want* the other axle to be driven by the siderods from the powered axle. 

The obvious reason is for doubled adhesion. With only one axle powered and with slight ups-and-downs in the track, the powered wheels will be struggling for grip. (Suspension/equalisation will help in any case, but that's another whole thread!) 

You seem to have grasped the principle of quartering - one side rod is at the top or bottom while the other is halfway at the middle of the wheel. Any other arrangement (if you have any side rods) will lead to binding. 

Can't help you with a picture of both sides of a loco, but NWSL sells a "Quarterer". Their description says: "Quartering is the term for setting crankpins of locomotive drivers at 90 degrees ‘crank’ apart (similar to an automobile crankshaft). Accurate quarter of all drivers in a set to the same angle (whether exactly 90 degrees or not) is critical for smooth operation of model locomotives." 










Finally, as Kenneth said on the early part of this thread, it is critical that the crankpin holes be at 90 degrees and exactly the same distance from the center hole. Your wheels may be stainless steel, which will make drilling very difficult. In any case, a jig to hold the wheels in exactly the same place under a drill press is highly desirable. Or take them to a machine shop with a lathe and get them to do it for you.


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## Pete Thornton (Jan 2, 2008)

I'm using spoked wheels so I probably would have to drill a hole thru one of the spokes 
Doubtful that will work - spokes are generally too thin. I suggest you try to find some alternate wheel with crankpins in them. 

how far down the spoke the rods need to be attached 
Up to you, but I'd suggest about halfway between the axle and the rim/tread. 

The further out, the easier time the bearings have and the more thrust is imparted - but the more centripetal force operating on the wheel and rod so the speed is limited. And vice versa.


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## SE18 (Feb 21, 2008)

thanks, this thread is a keeper for me! 

(I guess I'm too afraid to ask why NWSL sells a quarterer when all that one needs to do is locate it a quarter turn)


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## lownote (Jan 3, 2008)

If the siderods are light, and they aren't doing a lot of work--i.e. they are mostly cosmetic--you could try filling the space between two spokes and drilling that. I would try using the epoxy putty they sell in hardware stores--the stuff I'm thinking of is like clay. It comes in a plastic wrapped cylinder. You cut or tear off a chuck and knead it, which mixes the two elements of the epoxy. It starts getting warm and sets up fast.

Something like this:

Epoxy putty 

Pack the space between two spokes with the epoxy "clay," while it's still pliable, and let it set. Then you can sand it and drill it. I'm not really sure this would work, I've never tried it, but it might. You'd still want a counter weight, and you might be able to fake that up with the epoxy as well.


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## SE18 (Feb 21, 2008)

Thanks for the tip. I was kinda thinking in that direction. 

While you were posting, I did a minor edit: 

"(I guess I'm too afraid to ask why NWSL sells a quarterer when all that one needs to do is locate it a quarter turn) "


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## tacfoley (Jan 3, 2008)

Don't overlook the fact that in MOST locomotives I have ever seen, the right hand side cranks LEAD the left hand by 90 degrees.

To see what I mean, draw it out on piece of thin paper and then hold it up to the light, like this - 

1. draw a circle about three inches in diameter - this represents the drive-wheel.

2. draw a dot to represent the crankpin at 12 o'clock.

3. draw an arrow at 3 o'clock on the edge of circle pointing to the *right*. This direction represents the* front* of the loco.

4. draw another dot at 9 o'clock.

5. Turn the paper over and hold it up to the light with the arrow pointing to the *left. This direction now represents the front of the loco* - observe the position of the crankpin marker, now at 3 o'clock.

tac
www.ovgrs.org


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## lownote (Jan 3, 2008)

Depends on the degree of precision. Pete is mostly a live steamer, where precision really counts and where the rod is doing actual work as on a prototype. On more toy-like electric models, you often find very loose fits between the siderod and the mounting post, and that allows quartering to be a less precise operation.

I'm not sure why you need quartering in diesel. Do you really? Pete?


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## tacfoley (Jan 3, 2008)

Posted By lownote on 12 Jan 2010 08:59 AM 
Depends on the degree of precision. Pete is mostly a live steamer, where precision really counts and where the rod is doing actual work as on a prototype. On more toy-like electric models, you often find very loose fits between the siderod and the mounting post, and that allows quartering to be a less precise operation.

I'm not sure why you need quartering in diesel. Do you really? Pete? 


Well, yes, you do, as usually only one axle is driven on the full-size loco, or as you can see by looking at my own 1/3 scale 0-6-0 on our little railroad here in UK, a much larger model. The driven axle, in this case the rear jack-shaft, transmits torque via the side rods to the other axles - http://www.fenlandlightrailway.co.uk/e107_plugins/autogallery/autogallery.php?show=9.jpg 

The reason why most diesel models, like those made by LGB and others, have sloppy side-rods is that both axles on an 0-4-0 or the end axles on an 0-6-0 are usually driven by a double-ended electric motor, and the side-rods are therefore purely cosmetic. 

tac 
www.ovgrs.org


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## lownote (Jan 3, 2008)

I understand about the single driven axle--what I don't understand is why you need quartering. As I understand it, quartering is all about the pistons in a steam engine--that you could not have two pistons both fully extended, the train would then not be able to move after it came to rest. Quartering was intended to make sure you would always have some "push" in one of the pistons. At least that's my understanding.


But a diesel, driven by an engine with multiple pistons, would not have that issue. All you need to do is have the wheels turn together, and the rods could be placed anywhere. Or am I missing something? (Not trying to be argumentative here, just asking)


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## SE18 (Feb 21, 2008)

Most of you who do your own siderods, do you use the ubiquitous C or is it E clip to keep it on? 

I can't believe I'm asking all these questions, as a few years ago, I built a kit Ruby. Duh!


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## Semper Vaporo (Jan 2, 2008)

Posted By lownote on 12 Jan 2010 09:16 AM 
I understand about the single driven axle--what I don't understand is why you need quartering. As I understand it, quartering is all about the pistons in a steam engine--that you could not have two pistons both fully extended, the train would then not be able to move after it came to rest. Quartering was intended to make sure you would always have some "push" in one of the pistons. At least that's my understanding.


But a diesel, driven by an engine with multiple pistons, would not have that issue. All you need to do is have the wheels turn together, and the rods could be placed anywhere. Or am I missing something? (Not trying to be argumentative here, just asking)



Take a look at the following drawing. If the wheel on the left starts to rotate clockwise, the connecting rod will be pushing on the connecting pin on the wheel on the right. BUT that will not necessarily make it rotate clockwise also. The weight of the rod is also pushing down on the pin it is connected to and thus that wheel may rotate counter-clockwise (anti-clockwise).

If there is a second connecting rod on the opposite side of the locomotive at 90-degrees to that shown (and the axles are solid across the locomotive!), then that rod would be pushing (or pulling, if at -90-degrees) and will make the wheel on the right to turn also clockwise.


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## SE18 (Feb 21, 2008)

Great diagram, 

It seems like with this sort of arrangement, the going would be tough just starting out until momentum and centrifigal force kicks in


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## lownote (Jan 3, 2008)

Aha! that makes sense.

Starting out was always the hardest part with steam engines. They sometimes employed a "booster" on the trailing truck, a little steam driven motor that kicked in at start and then cut out at say 20 mph


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## Semper Vaporo (Jan 2, 2008)

With opposite sides at 90-degrees from each other, when one piston is near the end of its stroke, and thus about out of power, the other piston is just getting started and is at maximum power. Since the pistons are double acting (power on both the forward and reverse strokes) there are 4 power strokes per revolution of the wheels which smooth out quite nicely.

I have books that describe what to do if one side is broken (severed drive rods or pins, or otherwise incapacitated cylinder) and thus the loco has lost half of its power and, more importantly, lost the ability to start with the wheels at any angular position. The engineer had to watch the side and stop the loco with the rods either at the top or bottom and not half way between. If they did accidentally get stopped such that the piston had no power to make it go, they had what was called a "pinch bar" that could be inserted behind a wheel someplace and pulled down and that would just inch the engine forward slightly... multiple applications would eventually move the engine far enough to get the remaining good piston in a position to move the engine on its own and momentum would keep it going for the next stroke.

It was said that a Steam Locomotive could pull a train it cannot start and a Diesel can start a train it cannot pull.


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## tacfoley (Jan 3, 2008)

Posted By lownote on 12 Jan 2010 09:16 AM 
I understand about the single driven axle--what I don't understand is why you need quartering. As I understand it, quartering is all about the pistons in a steam engine--that you could not have two pistons both fully extended, the train would then not be able to move after it came to rest. Quartering was intended to make sure you would always have some "push" in one of the pistons. At least that's my understanding.


But a diesel, driven by an engine with multiple pistons, would not have that issue. All you need to do is have the wheels turn together, and the rods could be placed anywhere. Or am I missing something? (Not trying to be argumentative here, just asking)


Sir - the engine in a simple diesel locomotive does NOT drive the wheels directly in the same way as a steam engine does. The diesel engine drives a gearbox/transmission, usually with a single output shaft, like the gearbox of your car drives a prop shaft on a rear wheel drive car.
Because the output from the gearbox on this simple diesel loco only goes to ONE axle, there has to be a way that the power can be shared with the other one of two axles - hence the connecting rods - please look at the example of my loco that I posted to see what I mean. The power from the engine goes to the rear jackshaft, which then passes on the power to all the other axles by the connecting rods

Bigger diesel locomotives that do not have rods connecting the wheels either have multiple gearboxes or use the diesel engine to drive generators that provide power to traction motors s on each axle individually. All of the class 1 diesels you see hauling freight and passengers around work like this. Only switchers and short lines have rod-connected diesel locos.

tac
www.ovgrs.org


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## lownote (Jan 3, 2008)

I understand about the need for connecting rods--it's the need for _quartering_ in a diesel I was talking about. Semper laid it out.


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## Greg Elmassian (Jan 3, 2008)

I'm glad you asked the question Mike... was not finding a reason for quartering in a diesel either... Just like in Aristo steamers, don't really need quartering, just synchronized on each side, since the power comes from the axles, not the pistons. 

Regards, Greg


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## Semper Vaporo (Jan 2, 2008)

Posted By Greg Elmassian on 12 Jan 2010 06:40 PM 
I'm glad you asked the question Mike... was not finding a reason for quartering in a diesel either... Just like in Aristo steamers, don't really need quartering, just synchronized on each side, since the power comes from the axles, not the pistons. 

Regards, Greg 

If any axle derives its rotational power from the siderods then quartering is necessary. If all the axles are powered from individual motors or gearing from other axles or motors then yes, quarting of the side rods would not be necessary, but if they are all powered then side rods would not be necessary at all!


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## Greg Elmassian (Jan 3, 2008)

Right, but I thought it was shown that if the power comes from any axle, then you do not need quartering, just each side in sync, isn't that the point of Mike's question? 

Regards, Greg


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## lownote (Jan 3, 2008)

It still seems to me that you don't have to quarter the connecting rods in a diesel, but that you do have to make sure they are not in the same place on both sides--Semper's drawing shows that. And quartering would be a good way to insure that you don't end up with the scenario he describes, where the undriven wheel would want to go in the opposite direction. It doesn't seem to me that it would be a huge problem, but it would probably have a negative impact on efficiency at the start. But then I'm no engineer.


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## Greg Elmassian (Jan 3, 2008)

Ahh, so SOME offset, but not exact quartering... that makes sense... also not both in the same position, nor exactly 180 degrees out? 

Regards, Greg


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## Semper Vaporo (Jan 2, 2008)

If all the axles are driven then side rods are useless... only for "decoration" on a "toy" train... maybe necessary for the model's "looks", but useless functionality. 

But, for efficiencies sake, they do need to be pretty close to quartered, otherwise they could cause binding if the drive to each axle is of different torque/speed, which would be true if using a different electric motor for each one... no two motors will run at EXACTLY the same speed given the same Voltage/current (close, maybe, but NOT EXACTLY). The closer the decoration is to quartered the better... less chance of binding, less clatter, less uneven operation. 

I have some very poorly made toy trains (child toys) that bind because the side rods are at random locations. Even pushing the train by hand on the floor will sometimes result in the wheels locking up because the drive rods are not quartered.


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## tacfoley (Jan 3, 2008)

Let's just say that from an engineering point of view - ignoring what is a 'toy' and used decorative rods, and what is real and actually driven by rods. 

Since the invention of the operational and working steam engine, and its eventual 'child'. the internal combustion engine, wherever there are TWO linear/reciprocating inputs of energy [cylinders and pistons], the cranks are set at 90 degrees to each other to enable the efficient conversion from reciprocating motion to rotational motion to take place. Where there are, as in some steam engines, there are THREE inputs [like a Shay], they are [usually]set at 120 degrees, and where there are four, they are set at the same 90 degrees, but usually applied to different driving axles. 

In a rod-driven diesel locomotive, the actual driven axle rotates by virtue of being gear driven by a motor/gearbox at right angles to the direction of motion of the drive rods, NOT by the impulse of a reciprocating piston moving in the same direction as the drive rods. However, to ensure that binding can never actually take place, the cranks are set at 90 degrees relative to each other. Thus a diesel locomotive that has lost one side drive rods can still move, because the wheels are fixed on a common axle. 

tac 
www.ovgrs.org


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## SE18 (Feb 21, 2008)

If I may take this thread on a 90 degree tangent, I have a completely new question, that may be sort of elementary. 

In my particular case, I run stuff that just makes it around tight curves. If I had, say a critter, that just makes those curves without binding, would the addition of siderods perhaps then make the critter bind while trying to negotiate those curves (by linking all the wheels so they turn less freely)? 

I hope I phrased my question in an understandable format. 

Much thanks, I'm really enjoying these discussions and am learning a lot of essential stuff that apparently most of you already know. 

Cheers 

Dave V


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## Torby (Jan 2, 2008)

You wouldn't notice. Especially since your block drives both axels.


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## cephius (Jan 10, 2008)

SE18, 
In answer to your question about how far from the hub to place the crank pin, Pete's answer is correct if no piston is involved. With a drive piston the crank pin must be placed so that a full stroke of the piston results in a 360º rotation of the wheel. Early steam engines had rather short strokes so the pin was close to the hub. As the pistons grew larger and longer, the crank pin moved away from the hub. 

The distance from hub to crank is 1/2 the stroke length. I visualize this by aligning the wheel hub with the stroke motion. With the piston at dead center, the piston connection rod should exactly line up with the hub. Push the piston all the way out and you have a crank pin position on the wheel. Do the same thing with the piston all the way in. A compass circle drawn with the hub as the center using this distance will show the full travel arc of the crank pin and bisect the two points. 

Dave


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## SE18 (Feb 21, 2008)

thanks again, I feel sort of weird as Cape Cod Todd asked the original question and now I've hijacked the thread


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## cephius (Jan 10, 2008)

SE18,
Here is how the prototypes handled crank pins on a wheel with spokes. This is a large driver I drew with eMachineShop for a Standard gauge F scale model of Empire State Express #999.


Not sure if you can add to your existing hub to get these results.


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## SE18 (Feb 21, 2008)

Thanks, Dave. The cam device on a diesel looks somewhat different than the drawing you have for steam, but I suppose the principle still applies.


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## Pete Thornton (Jan 2, 2008)

why NWSL sells a quarterer when all that one needs to do is locate it a quarter turn 
You guys did a great job of filling in the blanks while I was sleeping, but here's one that didn't get mentioned directly. 

You need to quarter ALL the wheels identically - so the "Quarterer" is a jig that ensures all the wheels are identically set on the axles. If the front axle's wheels were quarttered at 85 degrees and the next one at 93 deg, then you'd get serious binding. 

would the addition of siderods perhaps then make the critter bind while trying to negotiate those curves 
The rods have little effect, as the wheels are (I hope) rigidly mounted on the axles. It's the slipping that has to occur as the axle traverses the curve, where the outer wheel has to travel further than the inner one, that makes the corners more work for a railroad car/loco.


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## Pete Thornton (Jan 2, 2008)

The cam device on a diesel looks somewhat different than the drawing you have for steam 
The 'cam device' (counterweight) actually solves the problem of drilling into your wheel. If you add a counterweight, crank and pin on each axle the wheels can stay as they are. Here's some examples: 










I found this at *http://modelenginenews.org/ed.2004.03.html*


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## DKRickman (Mar 25, 2008)

On the subject of mounting a crankpin on a spoked wheel... 

Why not take a piece of brass tube, notch the end, and fit it OVER a spoke? If you are careful to keep the tube parallel to the axle, and if you put them in the same place on each wheel, that should do the trick. Of course, that's easier said than done, and a jig would probably be needed to do it properly. You could also mount pins between the spokes. 

Just slop some epoxy around the hub and crankpin, then file it to a nice smooth shape when it cures. Make it look like the drawings above. 

On the subjects of quartering.. 
-If only one axle is powered by your motor, then the other WILL be powered by the side rods. If the rods and pins are well made and tight, it will roll amazingly smoothly. And no, it should not bind appreciably in a curve, unless your mechanism depends on a LOT of axle sideplay to get around a curve. If the rods are loose, the second axle will still be powered, but it will rattle and clank and not run as smoothly. A little slop is needed to accommodate axle movement and so forth, but only a VERY little bit. 
-Any mechanism with rods connecting multiple axles needs some form of quartering. Steam locos with two double acting pistons work best with 90 degree quartering, engines with three cylinders work best with 120 degree quartering. As has been said above, diesels and electrics, not having any pistons connected to the rods, are less critical, but there does have to be some quartering (anything but 180 or 360 degrees) to prevent binding. 

General comments.. (some have been made by others as well, but I feel like rambling, so enjoy or ignore at your leisure) 

Side rods, if properly made, should never cause a mechanism to run less freely. I've seen steam loco chassis assemblies so well made that a light flick would set the wheels turning until the friction int he main bearings eventually slowed them to a stop. I've seen freight car trucks with wheels that didn't run anywhere close to that smoothly. 

Side rods were used on electrics and diesels for two reasons. One is that you could mount a large, heavy motor on the chassis, where the weight is supported by the springs, and still drive the axles. The other is that traction motors, especially early on, were expensive and heavy. If you could make one work for two axles, you saved a lot of money. A secondary advantage was that by linking multiple axles, there was less tendency for any one axle to lose traction and slip. You had to slip an entire truck. In the days before traction control electronics and wheel-slip detection, every little bit helped.


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## SE18 (Feb 21, 2008)

thanks for the ideas, again! 

Nice diagrams, Pete. I think B seems most common for diesel critters I'm modeling. Saves time to attach to the center


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## cape cod Todd (Jan 3, 2008)

Wow you ask a simple question and BAMMMM !! 

Actually it's GREAT ! I just learned more about side rods than I thought I needed to. Once again this forum and the fine people that frequent it bring an absolute wealth of information to any inquiry. After looking at my photos I found another engine of the same type with closed in sides that don't show the rods. That would be an easier one to model. Thanks Guys.


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