7mm Scale GWR Signals

Stephen Freeman

Western Thunderer
Good Afternoon,

I thought it might be of interest if I posted a couple of photos of some of the signals that I have built, some may have been on RMweb, not sure now but I never put everything on there and some have not made it in front of the camera, just the more unusual ones
.
The lamps are Modelu with SMD lights for illumination. Finials are also Modelu, operation is by servo motors controlled by Megapoints Control board.

The square posts are from brass etches of my own design, supplied by PPD. I have also done some Youtube videos and I will try and post some links tomorrow, there should be one of a Ground Signal too.
GWRbrad1.jpg
yelvertonstarter1.jpg
 

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jonte

Western Thunderer
Hello Stephen.

I’d be interested to learn more about their construction, especially in relation to the fitting, powering and sourcing of the SMD lights in 4mm scale. Do you have any step-by-step photos of construction you’d be willing to share?

Jonte
 

Stephen Freeman

Western Thunderer
Hello Stephen.

I’d be interested to learn more about their construction, especially in relation to the fitting, powering and sourcing of the SMD lights in 4mm scale. Do you have any step-by-step photos of construction you’d be willing to share?

Jonte
All in good time. SMD lights in 4mm scale is more difficult of course but not impossible, I have even done it in 2mm scale now that's difficult.
 

Stephen Freeman

Western Thunderer
Photos, don't really have any, it is all so small I have difficulty getting any worthwhile shots. I will try to do some over the weekend.

Basically:

Lamp - Modelu are nice and hollow and don't have insulation issues, the only problem is keeping the light from shining through where it shouldn't. Whitemetal lamps have to be carefully drilled out, no lighting issues but there is the question of insulation.

Where insulation is needed an application of Superglue usually does the job.
To stop light coming through where it shouldn't, first paint with a reflective paint (aluminum etc) which is non-conducting, just black won't don't it.

SMD LEDS, In 4mm scale we are interested in the sizes 0603 and if they are too big 0402 ( obviously 0402 is smaller and more difficult).

I know that you can get these pre-wired but I prefer to do my own because:

  • I have control over the wire length and thickness
  • It's cheaper
  • I can use wire which is easier to hide in the post
  • I use 0.19mm solderable enamelled copper wire
To actually solder them to the LEDs is another matter.

  • First secure the wire in whatever means you prefer, I use a pair of tweezers of the normally closed variety
  • Using the smallest tip in your iron set it to 350 degrees C (going higher risks destroying the LED).
  • Tin the end of the wire, you may have to scrape the varnish off a bit
  • trim to size
  • don your Optivisor or similar
  • Flux the LED
  • holding it in a pair of fine tweezers, solder the LED to the wire, don't linger.
  • Repeat for the other pad
Now you need to test it. Add a 1k resistor temporarily (It will have to come off to go through the post). then connect to 12vdc
After checking it works, make a note of the polarities of the wires.

If you need to add insulation, you can do it now.

If you are using a brass tube for the post, it needs to be drilled to thread the wires through. If it's a tapered square post then you need one of mine or one like it. They are 2 part brass etches, which leaves a hollow centre.. Again drill to thread the wire through.

Fitting the lamp to the wired LED is simply a matter of superglueing it on.

Once you have threaded the wire though you can re-attach the resistor (I use SMD ones they are a lot cheaper than the wire ones) to the positive wire. To attach to a servo motor, positive goes to red and negative goes to black (or brown depending on the servo).

Bracket signals are a bit more difficult but the same principles apply.

Can't think of anything else at the moment.
 

Stephen Freeman

Western Thunderer
I forgot to mention that I usually buy mine from Bright Components. I sometimes use RS but not usualy for leds as their post/minmum order is a bit much when I only want say 50 leds.
 

jonte

Western Thunderer
Photos, don't really have any, it is all so small I have difficulty getting any worthwhile shots. I will try to do some over the weekend.

Basically:

Lamp - Modelu are nice and hollow and don't have insulation issues, the only problem is keeping the light from shining through where it shouldn't. Whitemetal lamps have to be carefully drilled out, no lighting issues but there is the question of insulation.

Where insulation is needed an application of Superglue usually does the job.
To stop light coming through where it shouldn't, first paint with a reflective paint (aluminum etc) which is non-conducting, just black won't don't it.

SMD LEDS, In 4mm scale we are interested in the sizes 0603 and if they are too big 0402 ( obviously 0402 is smaller and more difficult).

I know that you can get these pre-wired but I prefer to do my own because:

  • I have control over the wire length and thickness
  • It's cheaper
  • I can use wire which is easier to hide in the post
  • I use 0.19mm solderable enamelled copper wire
To actually solder them to the LEDs is another matter.

  • First secure the wire in whatever means you prefer, I use a pair of tweezers of the normally closed variety
  • Using the smallest tip in your iron set it to 350 degrees C (going higher risks destroying the LED).
  • Tin the end of the wire, you may have to scrape the varnish off a bit
  • trim to size
  • don your Optivisor or similar
  • Flux the LED
  • holding it in a pair of fine tweezers, solder the LED to the wire, don't linger.
  • Repeat for the other pad
Now you need to test it. Add a 1k resistor temporarily (It will have to come off to go through the post). then connect to 12vdc
After checking it works, make a note of the polarities of the wires.

If you need to add insulation, you can do it now.

If you are using a brass tube for the post, it needs to be drilled to thread the wires through. If it's a tapered square post then you need one of mine or one like it. They are 2 part brass etches, which leaves a hollow centre.. Again drill to thread the wire through.

Fitting the lamp to the wired LED is simply a matter of superglueing it on.

Once you have threaded the wire though you can re-attach the resistor (I use SMD ones they are a lot cheaper than the wire ones) to the positive wire. To attach to a servo motor, positive goes to red and negative goes to black (or brown depending on the servo).

Bracket signals are a bit more difficult but the same principles apply.

Can't think of anything else at the moment.

I forgot to mention that I usually buy mine from Bright Components. I sometimes use RS but not usualy for leds as their post/minmum order is a bit much when I only want say 50 leds.

Most kind, Stephen.

Thank you for a prompt and comprehensive response.

There’s no need to post photos if not readily available; your step-by-step instructions are easy enough to follow :)

Jonte
 
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