Searchlight signal build?

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rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Tue Sep 19, 2017 12:28 pm

Well I've got a complete signal head "box". I set out to make one with more or less of the shelf parts to begin with, so here is what I came up with and a little verbal DIY on how to do it.

1/2" type LB conduit body. I used plastic but they are available in metal too.
http://www.homedepot.com/p/1-2-in-Type- ... 043487-_-N

1" Pipe coupler, female slip fitting to female NPT. Cut most of the threaded portion off leaving about 1/4" of threads inside. Then grind out the "stop" collar diameter inside just a little so the end with the few threads fits over the outside of the collar protruding from the back the conduit body. Rough up the area's to be glued with scotch bright and glue with red hot(it's blue lol) pipe cement.

Purchase a western safety head lamp, the incandescent one, $2.99 at Harbor Freight. Remove the rubber thing, spin the lens off, and remove the reflector from the lens, it might take a tap or two. The headlamp can still be used too it's just not quite as bright.
Enlarge the hole in the reflector for the LED(s) of your choice. In my case I made a peanut shaped opening for 2ea 10mm LED's with a dremel. Make these fit your leds as tight as you can. Then use the pipe cement around the edge of the reflector and the end of the 1" pipe coupler and glue them together. It has a little play so center it up the best you can. The red hot pipe cement sets fast!

Insert your LED's and any wires/resistors in through the cover of the conduit body until the LED's pop into your opening in the reflector, then fill the back of the opening(inside the conduit body and behind the reflector), with clear silicone sealant. Wiggle the wires around a little so it fills up the hole nicely. I used GE's 30 minute stuff. Put the assembly reflector-face down on the table/window sill while it sets.

Finally, the lens. I found some 40mm diameter glass "cabochan's", these are a convex on one side, flat on the other side, lens used to sandwich photo's or whatever that are available in craft shops. Incidentally, in 2" scale they are almost perfect size to the real thing. Using a little piece of foam to protect it, I C-clamped it over the reflector, and applied a bead of DAP black silicone sealant around the edge and in the groove with my finger. Make sure the sealant doesn't stick out from the side much, as the target and sunshade will slide over this finished assembly.

I haven't built my target yet, but plan to tonight. 1-1/2" aluminum pipe slips nicely over the outside of the finished assembly, so I'm planning to cut a round aluminum disk from sheet, screw it into a little chunk of pipe shaped for the "eyebrow" and slide it onto the assembly I built. One could use a CD disk and some PVC or ABS pipe, drill the center hole bigger, and just glue it together.

Further thoughts, the 1/2" pipe fitting exiting the conduit body can be dealt with in a couple ways. It can be mounted directly to a PVC or aluminum mast, for the easy way, or to look more prototypical, it can be bushed down and mounted to the post with brackets, then a piece of tubing can carry to the wires to the mast like the real thing. Over time PVC will be affected by UV light. I have however noticed that the PVC conduit on the side of my house is 20 years old, and although it's faded from grey to almost white it's not crunchy or cracked. I think with the use of a good primer and spray galvanizing over the plastic parts, they will last a long time.

I'll update my post with the 2nd half, the base and ladder, platform, soon. I'm going to try setting up a new photo site so I can post some pics for you guys of my locomotive, track, and signal build.

rkcarguy
Posts: 260
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Re: Searchlight signal build?

Postby rkcarguy » Tue Sep 19, 2017 8:20 pm

https://imageshack.us/user/rkcarguy

This will get you to all my pictures on imageshack. Just uploaded pics of the signal head lit with each color.

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BigDumbDinosaur
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Re: Searchlight signal build?

Postby BigDumbDinosaur » Tue Sep 19, 2017 11:10 pm

Erskine Tramway wrote:At Sandley's, we used to get our 1-1/2" diameter Fresnel lenses for class lamps, markers and signals from Kopp Glass Company. Can't say if they're still in business or not.....or how many you'd have to buy at once :shock:

http://www.koppglass.com
Science makes it known. Engineering makes it work.

rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Wed Sep 20, 2017 1:01 am

Most of my evening went to working on my loco's body, but I did manage to get the "eyebrow" cut, filed smooth, and painted. I like using BBQ paint for this type of thing, I preheat the part and spray it on, then use the propane torch to bake it on. Uploaded a couple new pics to imageshack.
I need to make the target a bit more round, and make a couple brackets to support it and it will get the same treatment. Then the head is done.

rkcarguy
Posts: 260
Joined: Tue Aug 22, 2017 10:33 am

Re: Searchlight signal build?

Postby rkcarguy » Wed Sep 20, 2017 10:33 am

http://www.trainweb.org/signals/usssls_types.htm

If I can come up with a prism lens for the inside I'll have a pretty close match of the H2 design.
I was giving train control some thought as well...at least a reactive design that responds to the trains position.
If I was to install a SPDT relay into each signal, the default setting could be set to red. The train being on a section of track would close the ground for the relay changing it to green. At the same time, a wire would return to the prior block signal changing it to red, with a diode installed so it can't feed back into the system. Then, another wire would proceed to the next block beyond that one, again with a diode, lighting up the yellow light. The only problem, in the case of multiple trains or a piece of rolling stock left on the main line in a "yellow" aspect, the green or red light would come on as well, because there is not any single pull triple throw relays lol. I think...I could pair a 2nd relay that would break the ground for the green and red colors when yellow is lit from 2 blocks away.

rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Wed Sep 20, 2017 2:32 pm

rkcarguy wrote:The signal on the left has that mini-light about 1/2 way up, what were the color options of that and what was it supposed to indicate?


It appears that when the RR's got cheap, this light would illuminate yellow and the searchlight above red, ordering the train to take the diverging route onto a siding. So this light is a yellow color only. These were used on Southern Pacific's cascade route in Oregon.

rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Thu Sep 21, 2017 10:47 am

https://imageshack.us/user/rkcarguy

The signal head is finished.

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neanderman
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Re: Searchlight signal build?

Postby neanderman » Fri Sep 22, 2017 12:04 am

Nice job!
Ed

Le Blond Dual Drive
US-Burke Millrite MVI
Atlas 618
Files, snips and cold chisels

Proud denizen of the former "Machine Tool Capitol of the World"

rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Fri Sep 22, 2017 6:01 pm

Thank you. It seems like it took along time to build, but in reality is was about 5 hours of work and a bunch of trial and error in seeing how things fit and so on. I want to make a couple fixtures and some sketches to help streamline things. I'm hoping to have 5 blocks and one passing siding, so this means I need a staggering 12 signals? !!!

rkcarguy
Posts: 260
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Re: Searchlight signal build?

Postby rkcarguy » Thu Sep 28, 2017 11:15 pm

Ok so I think I've got a relay system worked out.
The SPDT relays I bought have two outputs, one or the other on all the time. It takes two per signal to get it to work and somewhat mimics a "permissive" system with the red aspect default if I remember correctly.
Relay #1 lights the red, and once the train closes the relay by entering the block, it turns green. But, the output from relay #1 to green goes into the + power input for the 2nd relay first, then it's normally-on output goes to green. When this #2 relay is triggered by another train 2 blocks away, the green is dropped and yellow is illuminated. The relay outputs can also be switched, providing a constant green for clear track, red for occupied, and yellow for the next block being occupied.
Pitfalls...obviously in the red default mode, one train ignoring a red signal(set by the green going the opposite direction) would set a pair of greens and result in a cornfield meet...but there wouldn't be another signal once the same block was entered by both trains anyway. Also, this setup is train sensitive, so if there is no train in block #1 for instance, it's just going to show red, whereas I'm sure many of you have seen in real life, that a signal will turn yellow when a train is in block #3 even if another train isn't there to see the yellow aspect in block #1.

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Erskine Tramway
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Re: Searchlight signal build?

Postby Erskine Tramway » Sat Sep 30, 2017 2:58 pm

Hi rk....

Just for reference, and not remarking on your circuitry, because all my reference material uses circuits with 'real live' relays and such, here's how it works on the 'big railroad'. I've never worked in ABS (Automatic Block Signals) territory, but I've ridden the Domes on passenger trains on the Milwaukee and Burlington where it was in service and saw it operating. All of my 'mainline' career was in either 'Dark Territory' using Train Orders, or later, CTC (Centralized Traffic Control). I also have several International Correspondence Schools signal books.

Right off the top, in CTC territory, the only signals that the Control Operator, aka Dispatcher, actually has any control over are the 'Absolute' signals at the ends of sidings or multiple main lines. That also includes Crossovers between tracks. We always called it 'Double Track' on the BN, although, strictly speaking, double track and multiple mains are different things. Double Track is usually signaled in one direction on each track, known as the 'Current of Traffic', and multiple mains are signaled for both directions on each track. There are specific Rules for running against the current of traffic, or 'Wrong Main' on Double Trcak. In any event, the signals between the control points in CTC are just ABS, depending on track occupancy for their indications.

So, let's say that you being passed by another train that the Dispatcher is running around you on the main beside you, for whatever reason. As he gets away from you, you can see the signals 'clearing up' behind him, from Red to Yellow, to Green. On the BN, we had another, Flashing Yellow, which gave you a little more warning that you might be stopping two Blocks ahead. It's handy if you are running 'track speed' downhill with a Coal train to have a little extra notice :D Though, you can run 'track speed' all day on Flashing Yellows (Approach Medium) as long as you never actually pass a Yellow. As soon as the train that's passed you passes the next controlled signal, the Dispatcher can send a train towards you on that track. You know that's happening, because, as soon as the train is signaled into that section, you can see all the signals on the other main 'drop' to Red.

In ABS, if two opposing trains passed signals at the ends of single track at the same time, all the signals between them would drop to Red. The trains are operating on either Schedules or Train Orders that govern their movements, not the signals. It's entirely possible for a train to 'miss a meet', and end up out on single track in the face of an oncoming train. Even in CTC, that Red light doesn't even slow you down if you don't see it. I was only involved in one situation like that. Early one morning, when I was on the Engineer's Extra Board, the Crew Caller called me and asked "How soon can you get here?" "About 45 minutes." It was twenty miles on the 'old' highway, and I wasn't even dressed yet. "OK, get here as soon as you can, the Road Foreman is going to take you and a Brakeman out to Owens to relieve a crew." We got out to East Owens, and there sat 'One Eyed Tony" with all five motors and five coal cars out through the power switch. "I misjudged the stop" he said. Personally, I think his Conductor was really running, account he was on the Waycar, but his grip was on the motors. Out on single track sat a westbound empty, fortunately, he was more than a block away when Tony's train 'knocked down' the east Absolute and changed all the westbound signals Red.

If you've got questions, feel free to ask.

Mike
Former Locomotive Engineer and Designer, Sandley Light Railway Equipment Works, Inc. and Riverside & Great Northern Railway 1962-77
BN RR Locomotive Engineer 1977-2014, Retired

rkcarguy
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Re: Searchlight signal build?

Postby rkcarguy » Mon Oct 02, 2017 12:20 pm

Thanks for the insight, I know it's very complicated in real life and we'll obviously not have train control via another person or system in most cases. I think the best we can do is to signal our RR's to indicate occupancy of each block and apply "track rules" and signals to support those.
I've watched several train mountain video's and notice they have the flashing yellow, I've also seen it in real life as well. I am modeling an older era though, so the flashing yellow would be beyond my time. That said its totally doable, another relay from the block beyond to the yellow with a flasher on it and there you go.
I'm going to post a sketch of my track plan on image-shack with signals so everyone can get an idea of what I'm looking to do. My trackage is going to be personal with a rare visitor, so for me it's just getting the signals to perform as they should for the novelty and safety factor around the blind curve.


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