Large Scale Central

A "New" Idea From A VERY Newbie?

Modeling
#1

Howdy, Folks!

First, a bit about me.

Age 59, a broadcast engineer by profession, and going thru my 10th or 12th childhood.

MANY current passions; Ham radio nut of long standing, Irish Setters and canine agility competition, and last year, with NO previous experience, I bought a motorcycle! I’d never even ridden as a passenger on one before… and now I’m a biker, but not just on ANY bike; I ride a Hack Rig (i.e. sidecar bike)… a Russian built Ural, no less!!!

Well, I just got my first G scale loco, out of curiosity, from EBAY. Gawd help us all… we’re off to the races AGAIN!!! This SURE ain’t the O gauge Lionel, Marx, and Kusan stuff I remember as a kid! The possibilities of Bachmann G scale stuff boggle the mind!

Well, the model railroad gods are ganging up on me; at a garage sale some time ago, just for old times sake, I paid 50 cents for an unassembled Plasticville signal bridge and switch tower kit (O gauge). As a kid, I was always fascinated by that signal bridge… just thought it was the neatest thing around.

Obviously, this thing is useless to a G scale layout… but then an idea popped into my vacant brain.

If I remember correctly, O scale is 1:48, and Bachmann’s version of G scale is 1:24 (I understand that’s subject to arguments… uhhh… I mean “interpretation”).

Why not scale up the Plasticville bridge, and to make it stronger (that bridge has to be the most fragile kit Plasticville ever made!) fabricate the G scale copy out of K&E brass shape stock, soldered together?

It sounds do-able… but the idea of all the measuring the original bridge and drafting plans sounded like a whole lotta work. Then, inspiration hit.

Just take apart the O scale bridge, and put the structural parts into the Xerox machine at work, programming the beast for a 200% size copy… and what comes out of the copier’s delivery chute is a full size working template suitable for building the flat structual panels on!!!

It seems TOO easy… there’s just GOTTA be something that I’m overlooking here, most likely something dumb like a scale error. Anybody see any obvious Gotchas in this scheme?

Also, a related question.

Light signals on this thing would be easy to do, but IMHO they’re from the wrong time frame for the ubiquitous Bachmann 4-6-0 Generic Baldwin; I think we’re talking roughly circa 1900 or so. To me, that says “semaphore signals”.

Fabrication is sort of complex, but do-able, and probably inexpensively; I’m thinking mini stepper motors to move the semaphore arms; the ones that they use to drive the instrument clusters of new cars can be had cheaply, and they MAY be small enough to fit into G gauge stuff… obviously, driver electronics & interfacing are on a board in a different location.

My biggest problem (so far) with semaphones… I can’t find a reference on the Internet that tells you too much useful about semaphore aspects, and NOTHING about the significance of the rather intricate painting schemes they used. Can anybody here steer me in the right direction on that?

Thanks,

Tom “Mr. T.” Adams
Sun Prairie, Wisconsin

#2

Nice to meet you, Tom! That 4-6-0 is more modern that you’d think. It’s modeled after “Tweetsie” number 12, but gets dolled up for other themes. Now, I read somwhere when that loco was built, William let me read his book, but it escapes me now.

I’d think steppers might be overkill, but overkill is cool if you can get it at a good price:D

#3

Semaphores usually use the same coding as color light signals Red/Yellow/Green over Red… etc… but this varies a bit from railroad to railroad, unless you’re talking the really oldest and earliest pioneer versions with a zillion arms …

The shape of the blade often indicates permissive/absolute/other type signals, where a square end is absolute, and pointed is permissive… a special signal (Slide detector, etc.) often has a “fishtail” blade. Some railroads colored the blades based on type. Because semaphores predate anything like NORAC, the actual “flavor” of the system varied from place to place, but often followed the AAR convention on signalling.

But, that’s not what you asked.

Take a look at: http://broadway.pennsyrr.com/Rail/Signal/ … that should get you started.

Some folks have had success using a “Tortoise” switch motor by Circuitron to move semaphores. … there’s even the necessary three position controller already available for it.

Matthew (OV)

#4
Tom Ruby said:
Nice to meet you, Tom! That 4-6-0 is more modern that you'd think. It's modeled after "Tweetsie" number 12, but gets dolled up for other themes. Now, I read somwhere when that loco was built, William let me read his book, but it escapes me now.

I’d think steppers might be overkill, but overkill is cool if you can get it at a good price:D


Howdy, Tom! Nice to make your acquaintance!

This G scale loco is a fascinating hunk of technology, really. It’s big enough that you can do things with it like hide printed circuit boards inside, and as necessary work on it without watch maker’s tools. The obvious drawback is the size; these days it’s easy to understand why even HO is too big for a lot of folks. A buddy of mine at work has a short N scale train on his desk, but that stuff is, IMHO just TOO damned small to be any fun at all to work with… besides, he’s a scale nut; EVERYTHING has to be absolutely PERFECT, and just like the prototype. In N or Z scale, that’s just too anal retentive for me; if you need an illuminated magnifier on the workbench, it’s time to change scales! <>

In any case, the bug has a pretty good foothold on me now. My A.T. & S.F. 4-6-0 is so satisfactory that I just got high bid on another of the same, but this time a B & O liveried “Royal Blue”, complete with a combine and an observation from two other auctions. Watching a Royal Blue straight coach now to round it out.

In addition I’ve been able to get lowball bids on a few freight cars for the Santa Fe to pull, mostly beer logoed reefers! Considering changing the livery on the loco to the Alcohol, Tequila and Santgria ! Also looking for an unmarked tank car kits to be liveried for old Wisconsin bar label favorites, Korbel Brandy and Jack Daniels!

Gotta have SOMETHING to chase with all that beer! <>

Don’t know exactly what kind of a railroad I want to deal with here; since I have well over an acre of backyard, I’m toying with the idea of outdoor, done in hand laid stainless steel. But this is all in the very tentative stages at this point… but it IS a solution to the space problem with big scale stuff. For the area I’m considering, very rough estimates at this point say it would give me a main line of over 900 feet, with three straightaways of about 195 feet each. For power / control, I’m thinking straight DC at this point; got a big, fat ol’ control transformer here that would easily make a supply with 4 series pass transistor voltage regulators that at 18 VDC would current limit at 5 amperes each… and STILL have a 30% - 50% overload capacity of unregulated 24 VDC. That kind of a power supply should be adequate to power a pretty major amount of track.

Re. the stepper motors for semaphores… in terms of electronic control complication, it may well be overkill, but in other ways it’s not, in the opinion of a Newbie like me.

One thing that’s always irritated me about model railroads I’ve seen is that with mechanically actuated items like crossing gates, semaphore arms, etc. they ALWAYS seem to move much too fast. In the prototype world, a crossing gate doesn’t snap down instantly, and spring back up after the train passes.

The reason for the unreal movement is that understandably modelers want to adhere to the old acronym, KISS (“Keep It Simple, Stupid!”). A simple solenoid drive on a gate is pretty easy to envision and create, and cheap too.

Stepper motors are the key here. Without huge amounts of gearing them down. speed can be reduced, without losing torque, by simply reducing the clocking pulse frequency that you hit the motor driver chip with.

I’m not a heavy duty realism nut; if I was, I wouldn’t be considering playing with Bachman off the shelf stuff. It seems pretty toy like in a lot of ways. It’s bright and colorful, and only loosely prototypical. They’re FUN trains, with a touch of fantasy and whimsey about them. I think that’s where a lot of thier charm lies.

Once again, it’s nice making your acquaintance. I’m still exploring the site here, and no doubt there will be a LOT of questions as my newest addiction takes hold.

Keep On Keepin’ On,

Mr. T.

#5

<<This G scale loco is a fascinating hunk of technology, really. It’s big enough that you can do things with it like hide printed circuit boards inside>>

And gut them out, too!! :slight_smile: :slight_smile:
Welcome aboard, Tom!

TOG

#6
Matthew (OV) said:
Semaphores usually use the same coding as color light signals Red/Yellow/Green over Red... etc.... but this varies a bit from railroad to railroad, unless you're talking the really oldest and earliest pioneer versions with a zillion arms .....

The shape of the blade often indicates permissive/absolute/other type signals, where a square end is absolute, and pointed is permissive… a special signal (Slide detector, etc.) often has a “fishtail” blade. Some railroads colored the blades based on type. Because semaphores predate anything like NORAC, the actual “flavor” of the system varied from place to place, but often followed the AAR convention on signalling.

But, that’s not what you asked.

Take a look at: http://broadway.pennsyrr.com/Rail/Signal/ … that should get you started.

Some folks have had success using a “Tortoise” switch motor by Circuitron to move semaphores. … there’s even the necessary three position controller already available for it.

Matthew (OV)


Howdy, Matthew!

THANKS for that link! There’s a whole lot to absorb on it, but I think this is what I’ve been needing.

Mr. T.

#7

You’ll love that 4-6-0 loco. It handles tight curves nicely, hauls well, has great low-speed performance and is very reliable.

#8

Well… So Far, So Good on the signal bridge project.

This week, due to the regular guy getting called for jury duty, I wound up getting stuck with the Night Watch; Yours Truly is sitting here at the console of Wisconsin Public Television, keeping watch over a little bit of equipment until 6 AM… a bunch of video servers, 3 programming services (standard definition and HD TV feeding the entire state, plus the local cable TV service), and in my spare time monitoring Wisconsin Public Radio’s two programming services, and controlling a few statewide broadcast transmitters… 6 HDTV, 6 analog TV, 2 AM radio, 29 FM radio, plus a sprinkling of other stuff that we watch for several other agencies via a computer remote control system that would drive ya crazy.

Whew…

Despite all of this happy horse hockey, I’ve managed to find time to actually work on making the construction templates for the signal bridge. Nobody around to bug me a 3 AM, so let’s have at it.

Reprogramming one of the newer copy machines is a bit of a pain in the butt, quite frankly. After much fooling around, we finally got the silly thing to produce a 200% size copy of whatever was fed in. When I started xeroxing the parts of the Plasticville bridge, that produced a couple of problems.

First off… while this thing may optically blow up the object, what are ya gonna print on? A 200% size copy of O scale bridge parts is pretty huge, really.

I managed to locate some 11" x 17" copier paper… and that wasn’t really big enough. I had to copy the parts in sections.

Part of the problem is that I’m already beginning to kitbash this thing.

The original Plasticville signal bridge was intended to span a 2 track main line. I decided that I want to use it for that, plus a yard siding… a total of three tracks. So… I wound up expanding all horizontal components by 50%. Take the first copies and graft in 1/3 more structure.

NOW… even with 11" x 17" paper, there’s NO WAY that I can get it all on one sheet. The templates are patched together with a lot of Scotch invisible tape.

This thing is gonna be HUGE; after checking, it looks like I’ll have to graft the K & E brass stock together in some places to fabricate the longer parts. I haven’t measured it yer, but I’m estimating the span of this signal bridge to be over 18 inches.

I discovered that xeroxing Plasticville parts doesn’t produce a very sharp image… but it’s good enough to use for templates. They’ll be pinned to a sheet of plywood, and the individual brass members will be cut with a razor saw, per dimensions taken from measuring the part on the template sheet. The part will then be held in position on the template board with straight pins and / or surgical forceps (used to do that building R/C airplanes), and then it will be sweat soldered into place on the structural panels.

Once each of the three brass part panels are finished, they’ll be tied together with joiner members, and finally attached to the end support panels.

For the top catwalk on the bridge, I’m thinking about individual basswood planks, suitably stained.

I note that Plasticville molded on gusset plates at the joints of the structural steel members, complete with rivet heads. I’m debating if I want to go to that level of detail… soldering on a bunch of tiny brass plates, suitably dimpled with a center punch to simulate rivet heads, could get old REAL quick, IMHO.

Beyond this, I’ve been brushing up on stepper motor electronics theory for semaphore positioning. It looks do-able. The biggest problem is finding steppers that are small enough… but I think I have a solution.

I have a couple of Sony S-VHS video tape machines that are destined for the scrap heap. I believe there are some very small steppers in the tape threading mechanism that should do nicely for G gauge scale signal applications. Besides that, the mechanism is full of small nylon gears that should be useful in fabricating a semaphore drive mechanism.

Best of all… I’m betting that there are numerous stepper motor driver chips in the machine to use in the control electronics board.

At the end of the month I’m taking a couple of weeks off from work (before I go stark raving insane!) while the Old Lady heads to Arizona for a BIG dog show, along with the agility dogs. Me and old Arby (a retired canine agility competitor) will be left alone for 2 whole weeks!

At the very least, I should be able to construct this monster signal bridge without being bothered in that time. Maybe I’ll get lucky and also be able to figure out my semaphores for it too.

For the base anchors for the vertical supports, I’m toying with the idea of using molded Plaster of Paris, mixed with sand, and possibly coated with clear, pale yellowish varnish to simulate concrete anchors.

The scary part of all of this… in the same package with the signal bridge, I also got a Plasticville switch tower. Switches and signals, especially when they control entry to a small yard, don’t sit out there in a vaccum… my head is already toying with the idea of blowing up and duplicating the tower.

Oy Vey…

Mr. T.