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Driving Rods on Brass Locomotives

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Driving Rods on Brass Locomotives
Posted by Oregon_Steamer on Wednesday, May 20, 2020 8:51 PM

Does anybody know what rods on brass locomotives are made of? It doesn't appear to be brass, it's not zinc, and it can't be steel since it's not magnetic.

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Posted by wvg_ca on Wednesday, May 20, 2020 10:03 PM

usually it's stainless steel ..

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Posted by wrench567 on Wednesday, May 20, 2020 10:04 PM

Hello.

 Never gave it a thought. Chrome or Nickle plated bronze would be my guess. My bowser rods are steel and most of the valve gear too. My Sunset brass steamers have a combination of plated bronze and steel. Some of the little links and the cross heads are steel or potmetal. My MB Auston valve gear links wore through the brass rivets and had to be re riveted. The links were steel. Side rods should be some sort of material to minimize wear to the crank pins. Bearing bronze would do the trick. Also easy to repair using solder and reaming.

   Plating on the drivers is an issue with some of my steamers. Bronze is not a good conductor and my worn wheels do some sparking sometimes.

       Pete

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Posted by TwinZephyr on Thursday, May 21, 2020 8:06 AM

Nickel silver.  Maybe nickel plated brass.

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Posted by SeeYou190 on Thursday, May 21, 2020 11:29 AM

I have no idea, and I was never concerned about it. I assume it would be nickel, but not sure.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by Oregon_Steamer on Thursday, May 21, 2020 1:55 PM

And another question why are they so detailed with grooves but they use unrealistic flathead screws on them while conventional models have a more realilistic hex nut? 

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Posted by Darth Santa Fe on Thursday, May 21, 2020 6:07 PM

Oregon_Steamer

And another question why are they so detailed with grooves but they use unrealistic flathead screws on them while conventional models have a more realilistic hex nut? 

 

That seems depend mostly on who made it. If the screw is flush or recessed into the rod, flat head screws don't need a special tool for getting them in and out, so that's why they get used so much. I think Ajin is one of the few that uses hex head screws.

_________________________________________________________________

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Posted by BRAKIE on Friday, May 22, 2020 6:25 AM

Oregon_Steamer

And another question why are they so detailed with grooves but they use unrealistic flathead screws on them while conventional models have a more realilistic hex nut? 

 

Because and according to my Dad any modeler worth his salt will have a collection of screwdrivers drill bits,taps and files of various sizes. 

I suspect that's why brass stream locomotives has screws and not hex screws.

Those tools my Dad mention was needed to build your average locomotive kit.

I still heed those words of wisdom but, added a hex screwdriver set to my collection of tools. The only thing I don't have is taps and calipers..Never found a real need for either. I use self tapping screws.

 

Larry

Conductor.

Summerset Ry.


"Your first mistake may be your last!" Safety First!

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Posted by Overmod on Friday, May 22, 2020 9:57 AM

Oregon_Steamer
And another question why are they so detailed with grooves but they use unrealistic flathead screws on them while conventional models have a more realilistic hex nut?

The cheap flathead-screw business is one of those 'conventions' in model railroading, like fixed-position valve gear pieces with rivets, or track without joint bar or tieplate detail, or nothing moving on the layout except the trains, that get established and people pretend not to see.  The tiny hex screws aren't much improvement, and I suspect can 'cam out' at the corners and become de facto security screws once a little corrosion between their threads and the dissimilar metal in driver centers gets going.

I have always thought the 'correct answer' here was to make up a small prototype-accurate 'cap' with the correct pin and nut detail, recess the screwhead a bit, and attach the cap to it with a small amount of adhesive.  You then pop this off if for some reason you need to get at the pins or take the driver out.  Mine were made with a little rib that engaged the slot in the screwhead for a little additional contact -- that was in the era before cyanoacrylates were more than an exotic industrial adhesive...  

Far more of a problem for me is how many of the rods themselves are stamped or apparently coined, and have the wrong shape, a crude cross-section, and ridiculously shallow and broad 'groove' detail compared to real rods.  I understand there is seldom money in the 'budget' for something like investment-cast (or high-pressure metal casting) rods, crosshead detail, etc. but for what a brass model costs something at least attempting to be realistic ought to be supplied.

 

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Posted by SeeYou190 on Friday, May 22, 2020 10:18 AM

For me, and I know this does not mesh with the current attitude of most modellers, locomotives are Machines first, and Models second.

I want my locmotives to be rugged, able to be handled, and easy to service/repair. I will accept less detail in return for a more reliable machine.

For me, Athearn Blue Boxes (with some added detail), proto-2000 models, and brass steamers from the 1960s - 1980s are great. The Stewart/Kato F units are perfect.

Those screws do not bother me.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by dknelson on Friday, May 22, 2020 10:30 AM

Mantua kits came with hex head screws and a tiny hex wrench to drive them with.  Build enough Mantua kits and you'd have quite a collection of those little flat wrenches with the hex shape.  Can I find mine now?  Nope.  

Even the old Lionel "scale" Hudson of the 1930s (really a nice model) avoided a slot screw to hold the valve gear together.

The classic advice back in the day was that if the slot annoyed you, fill it with a tiny bit of plaster or putty.  Easy enough to clean out if you did need to unscrew the valve gear. 

Dave Nelson.  

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Posted by Overmod on Friday, May 22, 2020 10:36 AM

SeeYou190
For me, and I know this does not mesh with the current attitude of most modellers, locomotives are Machines first, and Models second. I want my locmotives to be rugged, able to be handled, and easy to service/repair. I will accept less detail in return for a more reliable machine.

The critical point is that this doesn't have to be a 'tradeoff', and it certainly doesn't have to be a zero-sum game.

We're not talking the level of detail of accurate wire wheels on 1:43 model automobiles, assembled with surgical robots and if you even look at them funny they're ruined.  Nor can anyone pretend most of the current stamped-rod engines are particularly robust under rough treatment; it's astounding how quickly those cheap rods bend or deform (and have to be taken off via those convenient screws to be smithed to some reasonable approximation of straight).

I'm also not arguing that clearances in rod fit cannot be made much wider than the already-generous tolerances on the prototype locomotives to make the engines run better if quarter isn't perfectly consistent, or wheel displacement on contact springs needs to be larger than on 'real' locomotives.  We're talking the appearance of the components, or more accurately the dismal non-appearance of the usual conventional pieces that are provided.  Even making the current type of fake valve gear with straight milled edges and some proper etched rather than stamped detail would fix much of the 'casual viewing' visual problem with no real loss of reliability.

Of course, riveted flat pieces are reliable 'enough' even if it takes a great deal of tinkering with unrecoverable things like cheap rivets if the least little thing happens to them.  They are a good solution for the toy market, and heaven knows there's enough market for expensive toys with cheap detailing already.  But they're not a necessity to make accurate models necessarily reliable.

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Posted by wrench567 on Friday, May 22, 2020 10:19 PM

When the drivers are turning down the track it's hard to see if it's a slotted screw or a hex bolt. What I find interesting is the BLI locomotives I own have shallow hex screws. Most of my brass have slotted screws.

     Pete

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Posted by OT Dean on Saturday, May 23, 2020 1:04 AM

dknelson

Mantua kits came with hex head screws and a tiny hex wrench to drive them with.  Build enough Mantua kits and you'd have quite a collection of those little flat wrenches with the hex shape.  Can I find mine now?  Nope.  

Even the old Lionel "scale" Hudson of the 1930s (really a nice model) avoided a slot screw to hold the valve gear together.

The classic advice back in the day was that if the slot annoyed you, fill it with a tiny bit of plaster or putty.  Easy enough to clean out if you did need to unscrew the valve gear. 

Dave Nelson.  

 

I still have one or two--and even the snazzier little brass socket wrenches that one of the manufacturers provided.  These had thicker walls than K&S tubing and the hex was somehow hobbed inside (you could see the tiny curls of brass still clinging inside).  However, anyone who works on locos with these little hex crankpin screws should have a regular 0-80 wrench on hand to make short work of inserting and removing the screws.  My late brother (and model RR mentor) gave me the 00-90 and 0-80 wrenches about 60 years ago, so the plating on the steel is rather spotty and mixed with old rust from the basement atmosphere.  They're about 2-1/2" long, 5/16" in diameter, and the business ends taper down to get into close quarters.  The opposite half is knurled for a good grip.  It's easy to insert the heads of the screws and the hexes are deep enough that they don't usually drop out.  I bought the aluminum 1-72 wrench, which is made by Morris, a major manufacturer and supplier of machine screws, taps, and dies, later.  (I've had hobby shop dealers tell me the 1-72 is obsolete, but as my brother pointed out, "If an 0-80 screw hole in Zamak wears out, you just put your 1-72 in the hole, tap it, and use a 1-72 screw instead.")  There may have been a Morris socket made for 2-56, which is about the largest screw I encountered in HO, but I never had one.  A lady friend gave me a modelmaker's tool set in a plastic carrying case that had socket wrenches similar to the usual screwdrivers, with swivel knobs on the end, and I've used the 2-56 size quite a bit in O scale, where 2-56 screws fit a lot of things, particularly Kadee O scale coupler boxes.  (In O, I use 4-40, 6-32, 8-32, and even 10-32 screws for O scale steam loco models.  I'm equipped to drill and tap holes and thread rods.)  So, if you're working with hex-head 0-80 crankpin screws, you should be able to find what you need to ease working with them.  Now, if I could only find a supply of fillister-head screws...

Deano

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Posted by FlyingScotaman on Saturday, May 23, 2020 8:23 AM

The other solution which Intermountain use on their AC-12 is a more prototypical looking pressfit, but then you only have the interference as security. MTH use a slotted screw at the multiple link joint on the primary drive wheels on the Allegheney and a small shallow hex on the others.

If I'm looking at them I prefer the Intermountain solution. If I'm running I'd take a mechanical solution.

DrW
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Posted by DrW on Saturday, May 23, 2020 4:17 PM

Darth Santa Fe

That seems depend mostly on who made it. If the screw is flush or recessed into the rod, flat head screws don't need a special tool for getting them in and out, so that's why they get used so much. I think Ajin is one of the few that uses hex head screws.

 

Interesting point. I checked my collection of Santa Fe brass steamers. Everything that was made after 2000 was made by Boo-Rim (imported by Division Point and Glacier Park) and has hex head screws. The screws even have rounded corners; you really have to look closely to see that they are not completely round. Of course, this is high-end stuff.

The only other examples with hex head screws were two 3160 class Mikados made by Samhongsa and imported by Key in 1988. For the time, they were top-notch, with a price of > $500 for the factory-painted version. Overall, it seems that what you pay is what you get...

JW

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Posted by Overmod on Sunday, May 24, 2020 11:30 PM

OT Dean
Now, if I could only find a supply of fillister-head screws...

Olander has them down to 000-120 and J.I.Morris (now Swissturn) says they can make 0000-160 if needed...

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Posted by OT Dean on Monday, May 25, 2020 12:35 AM

Wow, that's too tiny for my poor old eyesight!  I used 2-56 filister-head screws for smokebox cleanout plug covers on my first O scale loco, back when all my parts worked better (55 years ago).  I fabricated the bases of brass sheet with embossed rivet heads, curved the bases and soldered them in place after running in the screws with nuts inside the smokebox, then soldered a bit of wire into the slots to form the handles.  (Couldn't find the the Kemtron [any of you remember Levon Kemalyan?] castings locally and these looked authentic.)  I also used 0-80 fillister-head screws for 2-wheel pilot truck guide yoke covers, tapping centralized holes above the pilot truck axles, placing a #0 brass washer on each screw, snugged 'em in place, filled the screw slots with solder, and shaped 'em; fast, inexpensive loco parts.  Fillister heads came in handy for a lot of things, particularly if I wanted then recessed.  The fillister heads are stronger than round heads and the slots don't strip as easily.  Thanks for the info.  Stay safe.

Deano

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