Semaphore Signals - 4mm Scale (Mainly)

[coachmann]

When you said the signal was for 'Holt', is this the layout based on Delph? If so, I wondered where the signal was situated. Mighty fine workmanship all round.

[Steve Hewitt]

When you said the signal was for 'Holt', is this the layout based on Delph? If so, I wondered where the signal was situated. Mighty fine workmanship all round.

Yes, it is the "Delph" based layout.

Dave Holt, the owner, has a Blog on RMweb where you should be able to find all the detail you need.

 

Steve.

[Steve Hewitt]

Continuing with the Woodford Halse Lattice Bracket:

 

Unfortunately I failed to take any pictures of the assembly process, so here is the completed signal.

 

The signal is mounted on its transport frame, which simulates its future baseboard mounting.

The two servos are fixed on their small sub-board and located by the foundation tube which keeps everything properly aligned.

The LED is fixed into a short length of 1/8in ID brass tube, which in turn is fixed to the servo sub-board.

The end of the optical fibres terminate in a turned brass plug, which fits into the LED tube and ensures the end of the fibres face the LED squarely, and almost touch it.

 

These shots show some of the operating bits:

 

 

 

 

 

I'll post a short video on YouTube, and a link to it on here asap.

 

Steve.

 

 

 

[Jon Fitness]

Steve,

A nice neat bracket and lovely engineering as usual. I sometimes just batter on with a signal then suddenly remember I haven't taken any pics!

Like you, I may start up a Youtube thingy to post videos as the 2mb upload limit goes nowhere on here!

Keep up the good work.

JF

[Steve Hewitt]

Steve,

A nice neat bracket and lovely engineering as usual. I sometimes just batter on with a signal then suddenly remember I haven't taken any pics!

Like you, I may start up a Youtube thingy to post videos as the 2mb upload limit goes nowhere on here!

Keep up the good work.

JF

Jon,

 

Thanks for your comment.

Here is the video:

 

That is likely to be the last signal for a while!

I'm off to Dortmund with the Lime Street team tomorrow for nine days, then I've promised myself I'll build an new EM gauge chassis for an LMS 8F I built in 00 many years ago.

I really need to have something of my own to run past all those signals I built!

I also have some major domestic committments in the coming months....

 

I hope to be back later in the year with the first of a series of GWR signals - including Route Indicators - which I expect will be a bit of a challenge!

 

Steve.

[Highlandman]

Your work, as ever, is immaculate and an inspiration. I hope your trip to Dortmund goes okay and that Lime Street is well received. I look forward to your future GWR builds, especially the route indicators. Keep up the great work.

[Steve Hewitt]

That is likely to be the last signal for a while!

I'm off to Dortmund with the Lime Street team tomorrow for nine days, then I've promised myself I'll build an new EM gauge chassis for an LMS 8F I built in 00 many years ago.

I really need to have something of my own to run past all those signals I built!

I also have some major domestic committments in the coming months....

 

I hope to be back later in the year with the first of a series of GWR signals - including Route Indicators - which I expect will be a bit of a challenge!

 

Steve.

It seems ages since my last posting.........

 

We did have a good trip to Dortmund with Lime Street, and work continues on the EM gauge chassis for my old 8F. I hope to have it finished and running at Lime Street's next outing which is to the Blackburn show on September 7th & 8th. (Actually held in Accrington see: http://www.belmrs.org/)

 

The major domestic committments have been successfilly undertaken (daughter married in Florida and our annual holiday in France), so now I'm looking forward to getting back into the workshop.

 

 

Just reading up on GWR signals.........how I wish the reference books contained proper dimensioned drawings like the "Warburton" ones those of us more used to the LMS are so reliant on.

 

More soon, I hope

[coachmann]

This thread has come at a good time for me seeing as an interest in signals has recently developed. Interesting to see how you assemble some of the finer things.

[Steve Hewitt]

It does seem a long time since I built a signal and reported it on RMweb.

My next project is the first signal for a P4 layout of the GWR in the Londoin area, set in the 1945-47 timeframe.

Square posts, but with some later style arms are required, plus several Route Indicators, as this is a terminus, low speed area.

 

The first signal comprises a narrow three foot arm with ring and a Route indicator for two routes.

To be servo operated and with lights.

 

I'll post some photos shortly....

 

Steve.

[BR(W)]

Steve,

 

This thread exhibits some superb craftsmanship, and a wonderful insight into the real thing. I know that you've boned up about GWR signals, but may I just mention what I consider to be the 'signature' feature of GWR lower quadrants, that their maximum design drop was 60 degrees from horizontal, not the more common, paltry 45 degrees on lesser railways.

 

To me, at least, this always appeared to imbue GW signals a deep sense of deference and respect for passing trains and seemed to be a metaphor for the sense of duty, care and courtesy which permeated 'The Firm'. Fanciful? Me?

 

Cheers,

 

BR(W).

[Steve Hewitt]

This signal is to be constructed from a combination of MSE components, some Etches which my friend Les Green (of Lime Street Roof fame) has produced for me, and a fair bit of scratch-building.

 

Some may recall from a much earlier posting, that I made up a Route Indicator from an MSE etch a couple of years ago, whilst on holiday in Cornwall!

It was always intended to be used on this project, so here it is:

and here are the shutters:

 

The etches by Les Green are for the Lamp Brackets:

And a collection of various lampman's staging and handrails, drawn to scale from photos of the GWR Parts Catalogue in Vaughan's book:

 

The main post is a solid brass item from MSE, seen here with the Lamp Bracket and Arm bearing fitted:

 

This is one of the etched operating levers fro the Route Indicator, with an early attempt at the link for the shutter. Note the fine brass tube through the arm to give a more effective bearing, preventing wobble.

This link subsequebntly failed and a much better, if overscale, solution was developed. (Pics later)

 

Those familiar with GWR Wooden Post Route Indicators will know that the post is cut through to allow the operating levers to pass through it. The gap is bridged by steel plates which carry the lever pivots.

Mine are made from Nickel Silver:

 

Here the post has been cut and the joining plates added, together with a trial of the operating arms:

 

And here is the Route Indicator in place:

 

More soon........

 

Steve.

[The Stationmaster]

Steve,

 

This thread exhibits some superb craftsmanship, and a wonderful insight into the real thing. I know that you've boned up about GWR signals, but may I just mention what I consider to be the 'signature' feature of GWR lower quadrants, that their maximum design drop was 60 degrees from horizontal, not the more common, paltry 45 degrees on lesser railways.

 

To me, at least, this always appeared to imbue GW signals a deep sense of deference and respect for passing trains and seemed to be a metaphor for the sense of duty, care and courtesy which permeated 'The Firm'. Fanciful? Me?

 

Cheers,

 

BR(W).

Officially a GWR signal was 'off' when the arm was down below its horizontal centre line by 'between 45 and 60 degrees'  (and it was 'on' if it was within 5 degrees either side of its horizontal centre line)

[Peter Kazmierczak]

Love the "bounce" in the signals when they return to danger.

 

Excellent work.

Edited August 26, 2013 by Western Sunset

[Steve Hewitt]

Those who've followed my previous signal builds will know that I like to give them good foundations.

 

The first part is the Nickel Silver base plate:

This has been marked out and drilled for the following to be firmly located:

 

From the left:

• The bottom of the ladder
• The two guide tubes for the Route Indicator operating wires
• The main foundation tube for the signal post
• The guide tube for the operating wire for the signal arm (Not present on the prototype)
  On the prototype the push rod for the signal arm is driven directly by the Arms which move the Route Indicator Shutters, and is returned to danger by gravity.
  Gravity doesn't scale too well, so I will drive the signal arm by its own servo, with its controller wired in such a way as to ensure the arm moves at the same time as either R.I. Shutter.

Here is the main foundation tube. It was turned from brass bar, and drilled through to take the turned down bottom of the Main Post:

(Sorry I forgot to photograph the turned post)

 

Assembly of the foundation tube to the base plate:

Locate the tube in the plate, on supports which allow soldering.

 

Apply plenty of liquid flux, and two small pellets of solder:

 

A quick blast with the butane gas torch:

Leave to cool !!!!!

 

Clean off stains etc.

 

Try the post in its foundations:

 

Add the guide tubes for the operating wires, from 1/16in brass tube:

Secure a long length of tube, it helps to get everything square.

Then cut off at the top surface after fixing.

 

All three guide tubes fitted:

 

Finally, the main location tube for the whole signal.

This 5/8in dia brass tube will locate the signal in the baseboard.

 

It also protects all the operating connections where they pass through the baseboard.

 

Ultimately, the servo motors will be mounted on a small assembly which will use this tube to guarantee accurate location.

 

More in a little while....

 

Steve.

[Highlandman]

I will be really interested to see how you solved the signal arm operation as that is what I am struggling on in my build. My initial thought was to use the route indicator rockers to operate the arm and then use a small lightweight spring to return the arm to danger. As always the workmanship is fantastic and this thread is a great source of encouragement to keep having a go.

 

All the best

 

Highlandman

[Steve Hewitt]

Thanks for our comments.

Your proposed solution for driving the signal arm is very much like the prototype, with the spring to substitute for the lack of gravity.

On the prototype, I believe there is a short rocking bar between those for the R.I. Shutters which is connected to the arm push rod.

This will ensure the lower end of the push rod is under control, and moves vertically.

This short rocker has a plate attached which covers the R.I. Rockers, and is moved whenever either (or any) of them is raised.

(Like the slotting for a distant signal)

 

All this gets a bit fiddly in 4mm scale and very fragile.

It is also difficult to work out the various arcs of movement necessary to get the correct amount of movement at the signal arm.

A previous post mentioned the desired 60 degrees.

 

By controlling the arm with its own servo and controller, it should be straight forward to get the movement correct.

Hopefully I'll be able to demonstrate this as the project progresses.

 

Steve.

[Jon Fitness]

Hi Steve,

Excellent work as usual!

I built one of these early pattern GW route indicators in 7mm with 3 shutters. I used servos to drive the shutters (which in turn dropped the arm) and managed to get the arm to return to danger by weightbar/gravity. I suppose thats the advantage of the larger mass available in 7mm but a return spring would do the job instead! If it's any help it starts about here in my thread.

Cheers

JF

[Steve Hewitt]

Thanks Jon,

 

I'm pretty well committed to using the extra servo on this signal, but I will try a mechanical solution on a later one.

 

Steve.

[Steve Hewitt]

Moving the story on a bit....

 

The main post has been installed in its foundations, and the ladders, landings etc. added:

 

The finial, and support for R.I. lamp complete the static elements:

 

After a good scrub with "Cif", a ride in the ultrasonic thingy and a bath in celulose thinners, it was time to visit the paintshop:

 

After the full coat of Halfords best white primer, the red and black were brushed on:

 

By now, the lamps with their fibre optic cables have been fixed in place:

 

The Route Indicator bars have been blackened and fitted:

 

The shutters for the R.I. have been lettered:

That for Plat 2 has been replaced with a more horizontal one!

 

And the signal arm has been painted:

 

More to follow......

 

Steve.

[Welly]

I'm not into GWR myself but that model signal post is just exquistite!

[Steve Hewitt]

The next bit is the part I usually enjoy the most when building a signal - Making It Work!

 

First I make an assembly/test/transport frame:

This represents the location on the layout where the signal will be installed, being the same thickness as the baseboard surface, and an appropriate area clear of obstructions where the servos can be accomodated:

In this case the board thickness with cork topping is 15mm:

 

By careful measurement, and alignment by eye, the servo positions are determined and an assembly is cobbled together from plywood or MDF offcuts:

 

The correct positioning of this assembly under the baseboard is facilitated by aligning the holes (5/8in dia in this case), using a length of K&S tube from which the foundation tube had been cut earlier:

The servo assembly is secured to the baseboad by the two screws. Once positioned and secured, it can be removed and replaced accurately whenever required.

 

The ooperating wires, 0.4mm dia Nickel Silver, blackened with Gun Blue, are built up where they pass through their guide tubes by sleeving with 1/32in dia brass tube.

The lower ends of these tubes are then sleeved up to 1/16in dia with another length of tube which is cranked and formed to engage its servo motor "horn". (the operating crank):

 

These are assembled first so that the 1/16in tube will slide easily over its 1/32in mate.

Adjustment is then made by setting the servos  to their mid-position.

By using GF Controls units this is easily achieved using "Safe" function, which sets each servo to mid-position and holds it there securely..

With each servo in mid-position, the arms, or in this case, the Route Indicator shutters, are set to their mid position.

Will all in "mid-position", the 1/16in tubes are soldered in place on their 1/32in partners.

 

The observant will have noticed that the "Gas Light" LED has been installed on the servo assembly, and the fibre cables sheathed in protective tubing, terminated in a brass turning which allows easy connection.

 

I mentioned previously that I'd had to develop the links between the R.I. operating arms and the shutters.

Basically, the alignment wasn't perfect and the bottom of one shutter was bending instead of rising in its slot.

The solution involved extending the R.I. arm for the front shutter by about 1.5mm and making a link for each are/shutter which prevented any sideways wobbling:

Hopefully you can see what I mean in this photo.

 

At the end of this we get three main sub-assemblies:

 

The signal, the assembly frame and servo assembly.

 

More to follow..........

 

Steve.

 

 

 

 

 

[Jon Fitness]

Beautifully engineered sir!

Jon F.

[Steve Hewitt]

Now for the servo controllers.

 

There are three servos, so I'll be using two GF Controls "two servo" units.

(The un-used controller will be utilised on a different signal at a future date.)

 

For testing and demonstration purposes, I've put this little unit together:

 

The controller on the left controls each of the two Route Indicators.

The controller on the right controls the signal arm.

The two switches represent the signal levers in the controlling signal box.

Pushed away the signal is at danger, no route shown.

Pull one switch (lever) and the Route shutter rises, and simultaneously, the arm drops to clear.

The other shutter is raised by pulling the other switch.

If both switches are pulled, the arm returns to danger and the shutters are both hidden.

(This is a form of electrical interlocking).

 

To achieve this, the switches are double pole double pole changeover "DPDT" type.

 

On each switch in this view, the left hand pole controls one Route shutter.

As the switch opens to move one servo to "Clear", the other side of the switch closes to ensure the other servo is at "Danger".

 

The right hand pole on each switch controls the signal arm servo.

They are wired together so that if either switch is "pulled" the servo for the signal arm moves to "Clear".

If both switches are in the same position, then the arm will be at "Danger".

 

The following colours have been used;

Green is common return from all the servo controllers.

Blue is the Switch connection to the "Plat 2" route indicator.

Yellow is the Switch connection to the "Plat 3" route indicator.

Red is the switch connection to the "Arm" servo.

Brown is the link between the two "Arm" poles to ensure the circuit is open if either route is set.

Hopefully this will enable you to find your way through the spaghetti.

 

Putting it all together:

Includes the battery for the LED light source.

 

The result:

 

 

 

I'll post a short video on YouTube when I can edit it!

 

Steve.

[Steve Hewitt]

And here's the video:

The final part of the clip shows the effect of turning off the "bounce".

 

Steve.

Edited September 30, 2013 by SteveAtBax

[The Stationmaster]

Lovely job although I find it interesting that it reads from a Goods Line to a couple of platform lines