3D Semaphore Signals

[AlanL]

I have been thinking about making semaphore signals for quite a long time but did'nt know where to start.
There was a recent thread on this forum about a 3Dprinted signal that was featured in Garden Rail magazine.
I managed to borrow a copy of the magazine to find out more. The 3D files are available to download for free and I used them to print my own signal. After printing the parts, assembly and some painting, I was really pleased with the end result except - it is scaled for narrow gauge.

One interesting feature of the model is that it has a 3D printed hole within the post. It is'nt a straight hole but a hole that bends into the side of the post near the lamp and exits the side lower down near the base. This is impossible without 3D printing!

Inspired by this wrong size signal, I decided to design a more G scale version.

Photo below of the 2 signals. The ladder and platform on the home signal show it's scale. The narrow gauge signal is 22cm tall and the G scale distant version is 20cm tall.


The distant signal is not quite finished, it needs the spectacle lenses fitting and also the lamp. The hole for the lamp wiring is just above the hoop and exits from the bottom of the post. The operating rod is welding wire until I can get some piano wire.
I have used a flat base for this signal but as these signals will be operated (indoors) with servos they will have a base incorporating a servo mounting

Photo below of the twin enamelled wire for the lamp exiting the post.



I am making a small quantity of these signals for our club railway to replace the existing colour signals.



To be continued ----

AL

 

[Paul M]

That looks pretty good, don't forget though that signals weren't always a standard size

 

[dunnyrail]

As Paul says, it is not really possible to say ’this is a narrow gauge signal’ unless you take some of the Ffestiniog types into account. These were quite different to the norm and Roundhouse make kits of the FR disk signals which look very nice. Many NG signals were in fact provided by the same companies that produced main line ones, though in some cases smaller but not exclusively. I think the GWR had (where provided) standard sized signals in the VofR and WnL lines though I am not so sure about the Corris.

In Germany there were not that many signals on the Ng though I do know of a few in sundry locations. Again these appeared to be similar to full sized ones.

 

[AlanL]

don't forget though that signals weren't always a standard size

If you were to put a 'G' scale figure on the platform he wouldn't be tall enough to see the lamp.

I nearly described the signal as 16 mm but wasn't so bold to be certain of the scale.

The platform is halfway up the signal, the lamp would be well above a G scale figure's head.

Any character would have to be about 10 cm tall to be able to work on the lamp, a giant in G scale

AL

 

[Paul M]

If you were to put a 'G' scale figure on the platform he wouldn't be tall enough to see the lamp.

I nearly described the signal as 16 mm but wasn't so bold to be certain of the scale.

The platform is halfway up the signal, the lamp would be well above a G scale figure's head.

Any character would have to be about 10 cm tall to be able to work on the lamp, a giant in G scale

AL

Yes the plans were for 16mm

 

[dunnyrail]

If you were to put a 'G' scale figure on the platform he wouldn't be tall enough to see the lamp.

I nearly described the signal as 16 mm but wasn't so bold to be certain of the scale.

The platform is halfway up the signal, the lamp would be well above a G scale figure's head.

Any character would have to be about 10 cm tall to be able to work on the lamp, a giant in G scale

AL

Signals are meant to be seen by the driver of a train looking from the engine cab, that would be a bit above someone standing on the platform. The lamp is for distant view and to help visibility in fog, falling snow and when it is dark. Nothing to do at all with visibility from an odd punter or the platform except perhaps the guard but he during the day would be looking at the signal, if at the rear at night the lamp would be visible.

 

[dunnyrail]

Below a couple of what we may consider ‘normal’ signals on the FR, though not on a platform or even with a figure in place I think it is fairly obvious that they are both quite large structures.
For those wondering about the aspects, one on the left with ring is for access to the run-round loop at Portmadog. The tall centre one to the main platform and the reduced height one on the right to the Welsh Highland Railway and Wharfes. This is a pre preservation view.

 

[AlanL]

Up to now it has been a simple assembly of 3D printed parts but now is the more tricky assemly, the signal blades and lenses.

I first printed the blades at a thickness of 1 mm, (the narrow gauge version was 2 mmm thick). I used white filament because that was a promenant colour on the back of the blade.
Then how to fit coloured lenses? Lenses on the back side of the blade needed something to frame them. I decided to print a spectacle back plate that was a shortened copy of the blade. The lens area was painted black ready to be glued. The lenses were applied individually.

However, once the back part was glued, the alignment was not too good ------ .

One problem was the mounting hole for the pivot. By design I had an M2 tapped hole into the boss of the main blade. I doubt that my printer would produce a tapped hole that small but the screws become self tappers and hold very well.


I tried again but this time I trimmed off the excess around the edges of the lenses before gluing on the back of the spectacle plate and acheived a much better alignment.


I then painted the blades, red with a white stripe on the front and white with a black stripe on the back. I didn't take a photo because it looked 'messy' and decided to print the colours on sticky vinyl. Again no photo because I didn't like the thick white line at the top of the blade where the blade thickness was showing.

The solution was to print a thinner blade and use a black filament. I took the thickness down to 0.6 mm. The blade was now very flexible but as I was using PETG I hope it is tough enough for reasonable abuse. You have to bend them forcibly before they go past their flat condition.

I also improved the method of applying the coloured acetate lenses. I cut the acetate into long strips and taped them as pairs to the workbench. I then applied super glue by dipping a small wire into a pool of glue an applying it carefully to the blade. I used a pair of forceps to hold the wire which made the job easier because the forceps do the gripping and you are just controlling the wire, like writing with a pen.

In this photo,the lenses are taped to the bench with masking tape and the signal blade is blue-tacked to a small base while applying the glue. With the glue applied, I lifted the acetate and slid the blade under until it was aligned. then allowed the acetate to drop onto the blade. The photo doesn't show the additional masking tape that holds the whole length of the acetate parallel. When the glue has dried, I used scissors to remove the blade from the acetate and then the acetate can be trimmed flush.

The next stage is to glue on the rear part of the lense. I used a long screw to aid location and applied super glue carefully as before.

Finally I applied the graphics to both the front and back of the blades. The graphics were sized to make this as easy as possible. The front graphics were designed to fit up to the mounting boss and the rear graphics were made to fit up to the back lens cover. The bades are 8 mm high and the graphics were made 10 mm high.
the blade is placed on my cutting mat lacated centrally between the centimetre lines. The graphics are then applied keeping it lined up with the lines on the cutting mat and the edge of the graphics touching either the boss on the front or the backplate on the back.

Below the bases are the built-in servo mountings and the wires for the lamps.These wires exit below the lamps and enter the post, exiting at the bottom of the post.
The counterbalance arms are pivoted on M2 cap head screws.

AL

 

[dunnyrail]

Very nice job.

German signals are somewhat different to UK ones, but I can see the files having minor adjustments to make simple single arm Hp stop signals for German modelling use. NG lines in Germany had a few of these.

Link to Wiki page of the genre including much of interest re German Signalling, ooops sorry for the thread drift but Signalling is a very interesting and complex business.

Railway signals in Germany - Wikipedia

en.wikipedia.org

 

[viaEstrecha]

Up to now it has been a simple assembly of 3D printed parts but now is the more tricky assemly, the signal blades and lenses.

I first printed the blades at a thickness of 1 mm, (the narrow gauge version was 2 mmm thick). I used white filament because that was a promenant colour on the back of the blade.
Then how to fit coloured lenses? Lenses on the back side of the blade needed something to frame them. I decided to print a spectacle back plate that was a shortened copy of the blade. The lens area was painted black ready to be glued. The lenses were applied individually.

View attachment 323849 View attachment 323850 However, once the back part was glued, the alignment was not too good ------ .View attachment 323851

One problem was the mounting hole for the pivot. By design I had an M2 tapped hole into the boss of the main blade. I doubt that my printer would produce a tapped hole that small but the screws become self tappers and hold very well.
View attachment 323852

I tried again but this time I trimmed off the excess around the edges of the lenses before gluing on the back of the spectacle plate and acheived a much better alignment.
View attachment 323853

I then painted the blades, red with a white stripe on the front and white with a black stripe on the back. I didn't take a photo because it looked 'messy' and decided to print the colours on sticky vinyl. Again no photo because I didn't like the thick white line at the top of the blade where the blade thickness was showing.

The solution was to print a thinner blade and use a black filament. I took the thickness down to 0.6 mm. The blade was now very flexible but as I was using PETG I hope it is tough enough for reasonable abuse. You have to bend them forcibly before they go past their flat condition.

I also improved the method of applying the coloured acetate lenses. I cut the acetate into long strips and taped them as pairs to the workbench. I then applied super glue by dipping a small wire into a pool of glue an applying it carefully to the blade. I used a pair of forceps to hold the wire which made the job easier because the forceps do the gripping and you are just controlling the wire, like writing with a pen.

View attachment 323854 In this photo,the lenses are taped to the bench with masking tape and the signal blade is blue-tacked to a small base while applying the glue. With the glue applied, I lifted the acetate and slid the blade under until it was aligned. then allowed the acetate to drop onto the blade. The photo doesn't show the additional masking tape that holds the whole length of the acetate parallel. When the glue has dried, I used scissors to remove the blade from the acetate and then the acetate can be trimmed flush.

The next stage is to glue on the rear part of the lense. I used a long screw to aid location and applied super glue carefully as before.
View attachment 323855
Finally I applied the graphics to both the front and back of the blades. The graphics were sized to make this as easy as possible. The front graphics were designed to fit up to the mounting boss and the rear graphics were made to fit up to the back lens cover. The bades are 8 mm high and the graphics were made 10 mm high.
the blade is placed on my cutting mat lacated centrally between the centimetre lines. The graphics are then applied keeping it lined up with the lines on the cutting mat and the edge of the graphics touching either the boss on the front or the backplate on the back.View attachment 323856

Below the bases are the built-in servo mountings and the wires for the lamps.These wires exit below the lamps and enter the post, exiting at the bottom of the post.
The counterbalance arms are pivoted on M2 cap head screws.

AL

Super job, Alan. One day, I'll have to commission one from you - I use colour light signals, but I need to find an excuse to have a lilac Spanish semaphore shunting signal, though it would be interesting to source a matching spectacle plate material. Can't even use a Quality Street wrapper, now they are foil wrapped.

 

[ge_rik]

The Isle of Man Railway was quite comprehensively signalled


Rik

 

[ge_rik]

As were most of the Irish narrow gauge railways


Rik

 

[AlanL]

Every railway should have signals! They are an important feature.

I installed working colour signals on my railway some years ago and automated their operation with the passing of trains. As a 'train watcher' it added an extra dimension for me. Inevitably I would watch a train and make sure the signal was green as the train approaches and then ensure that the signal changed aspect to danger after the train had passed.
The colour signals are rather plain and can only be seen from the front.
Excuse for a photo -
The signal with the ladder did not survive, it didn't look right so it was modified to be a plain post and easier to make more copies as in the second photo.!

I have always wanted to have semaphore signals but until the article in Garden Rail did not know where to start.

These first 3D signals are for indoor layouts (not mine) and have been an interesting project for the winter.

Now that I have a presentable design, it can be modified to suit individual needs by changing dimensions as needed. Even continental signals could be designed. My own railway is US 1960's and the US signals are (and I stand to be corrected) often motor driven without the mechanical rods and levers and a circular post, so they will be different.

My ultimate aim is to make US style signals for my own ground level railway that are servo driven and weather proof!

For the British mechanical signals such as these, perhaps a nearby lineside cabinet or hut could be used to hide and protect the servo?

Next job is to fit and wire the servo's

AL

 

[AlanL]

The signals are now wired and servos fitted. The base for the signals are where 3D printing comes into it's own because although it looks simple, it would be dificult to make by hand.

The wires to the servo were cut and the connector end saved to be re-soldered to the cable -

The 2 servo power wires are fed through the 2 holes -

A pair of resistors fed through the same holes were also used as a connection between the LED and the 5 volt power leads -

The legs of the resistors were bent over and soldered to each of the servo power leads and also soldered to the wires to the LED -


(Red wire was a little tricky, took too long!) Red wire attatched to one resistor - and the black wire to the other resistor -

Finally a multicore cable was soldered to the three wires, red positive 5 volts, black negative and white signal to the orange wire from the servo -
A cable tie secured the cable to the base through the pair of holes.



I'm using a modified servo tester to control the servos but that is another story (or thread).


Just over a year ago, I was doubtful that I needed a 3D printer and had to persuade myself to buy one even though I had little use for a 3D printer.
At the time I was making buildings and after making a number of windows by hand, decided to go the lazy way by 3D printing the window frames using a local company to print them.
I was (and still am) making a quantity of buildings and therefore needed plenty more windows so I decided that I should have my own printer because after paying over £40 for about 30 windows, I realised that I would save money in the long run by having my own printer.

Once you have a 3D printer, your imagination and your needs totally justify having a 3D printer. I have made all sorts of items, many of them not related to model trains.

I've learned the software design and I thoroughly enjoy designing things and then modifing and improving the design, it's part of the enjoyment of the hobby. In fact I must admit that the base for these signals has been modified several times!

Don't hesitate, buy one!

AL