Model signal operating mechanisms

[woodbine]

I have reached the stage with my 4mm layout when I can no longer put off the question of how to operate my yet-to-be-built semaphore and ground signals. I have shown willing and bought Mick Nicholson's book "Constructing and Operating Semaphore Signals", but it never even mentioned what happens "below ground", and I am reluctant to cough up for other books that may be similar. I wish Iain Rice had written one.

The best place therefore seems to be this forum. But even here most discussion is about what happens above ground.

I would like a rundown of the pro's and con's of whatever alternatives there are - a) Wire-in-tube and what happens when the wire reaches the mechanism as per the Wizard Models paddle system and maybe others. - b) Servo (I think i've already ruled out solenoid), MERG vs Megapoint and others, and again, what happens  with the interface between servo and signal i.e. servo mounting.

The most informative thread, in the sense that it gives a clear idea of How To Do It has been Steve Hewit's. It would be good if I could be pointed at other similar threads using/discussing other systems.

[31A]

I was waiting to see what people would say in answer to this, but there doesn't seem to have been a rush!  Most people these days seem to use some kind of electrical servo mechanism, but I use gravity in much the same way that real semaphore signals are usually worked.  A crank below the baseboard, with a lump of lead on one end and the other end attached to the signal.  The crank is connected to a lever in a lever frame by fishing line.  Some pictures might help.

 

Firstly the mechanism for a signal with two arms.  The pivot for the cranks is a 6BA bolt, and the holes in the cranks are tapped 6BA which means the cranks are screwed onto the pivot and no retaining collars or washers of any kind are needed.  In this picture, no 'stops' have yet been fitted.  The mounting is a section of aluminium angle; the mounting holes are tapped 8BA and the fixing bolts pass through the base of the signal and the baseboard, and then screw into the aluminium angle.

 

 

 

Next, the parts for a mechanism for a gantry which has six arms, although there are only parts for five in the picture.

 

 

The next two show the same mechanism attached below the signal on a test rig.  In the first picture, you can see the holes in the 'long' arms (which are made from lengths of old rail) where the cord from the lever is attached.  The cord running from the lever also incorporates a tension spring somewhere along its length, so that the lever 'over travels' slightly; this also gives a nice smooth action to the arm.

 

You can also see the 'Off' stop which is another bolt, slightly below the pivot bolt.  I also provide an 'On' stop on the other side of the cranks, against which the cranks drop when the signal is retuned to danger - if you get this 'just so' the signals will bounce in a random way when they are replaced to danger.  The stops should prevent the fragile scale parts of the actual signal from any stress from the cord being pulled.

 

 

 

 

This shows how the linkage was connected to the signal in this case.  Before installation, the upper parts of the connecting wires can be blackened to make them less obtrusive.

 

 

I hope this is useful!

 

 

 

 

 

[woodbine]

Very useful indeed and very clever! Even with days of searching yours is the first example of manual operation I've seen. What about the fishing line, where is it attached and how do you arrange to hold the signal off? Is it attached to a lever frame?

 

[31A]

9 hours ago, woodbine said:

Very useful indeed and very clever! Even with days of searching yours is the first example of manual operation I've seen. What about the fishing line, where is it attached and how do you arrange to hold the signal off? Is it attached to a lever frame?

 

 

Thank you, glad you find it useful!

 

To attach the fishing line, I make little double ended hooks from paper clip wire with the fishing line tied to one end and the other end is hooked through a hole in the crank arm.   The holes in the crank arm aren't evident in the photos (they are drilled through the  upright part of the rail that makes the crank arm) but you can just make them out in the third picture.  The fishing line is the braided type.  The spring in the fishing line thread run can be anything really, old ball point pen springs work well.

 

I've got two types of lever frame, one that I made myself mostly from brass sections etc, and the others are a type made years ago by A1 Models, sadly no longer available.  But there are some lever frames available commercially, for example the Model Signal Engineering one from Wizard Models, the Scalefour Society one and the old GEM one:  http://lytchettmanor.co.uk.websitebuilder.prositehosting.co.uk/lytchett-manor/mercontrol---point-control

 

Just the action of the lever latching in the 'off' position holds the signal off.

[Portchullin Tatty]

Woodbine

 

I use servos and I have come up with a little solution such that the servo is fitted to the signal base but the whole signal can be taken out for building or maintenance.

 

I came up with a number of tips associated with building and operating signals which you can find here

 

Or more generally on my signals as a whole see here

 

I prefer the MERG servo controllers but some of this is because I am used to them rather than they are necessarily better.

[woodbine]

Thanks for those links, I've had a look and found them very enjoyable and informative. There's lots of other stuff on there too, and I'll be back.

 

[Yan]

Excellent thread this. I've started to briefly to think about signals for my forthcoming project and what I might require so will follow with interest,

[KeithHC]

Just came across this thread very interesting. I wonder wether my simple 3D design and printing skills might come to the fore on this. I can see a standard being designed and then a simple print in multiples.

 

Keith

[Butler Henderson]

Anyone tried the Heathcoate bouncing mech ?

[woodbine]

1. Long posts coming, sorry. Settle down for a minute or two. I've prepared a short series of posts to answer my own question, since I perceive that there is a gap. I've tried to be brief and not repeat things.

 

Firstly, can I avoid making the signals myself? I could equip my layout with the various ready-made commercial offerings from Dapol, Hornby, or Ratio, but their ranges are naturally limited. Or if I want a well-made signal to my own specification then there are people on this forum who will make one professionally, and it will be better than anything I can produce! Of course that doesn't come cheap, and anyway I prefer the challenge of acquiring some of that skill.

 

Making the visible bits of semaphore signals seems achievable, following the help and advice available on this forum and in book form, and I needn't say anything about that in this thread. Though slightly daunting, the process appears straightforward and uncontroversial, with not many choices to make. Apart, that is, from the important business of deciding how to operate them remotely. So…

 

Semaphore Signal Operating Mechanisms.

 

Digging around on the forum I expected to find a commonly accepted best practice one-size-fits-all way of doing things. Silly me. It is the most mysterious business, with the most complicated choices to make and many options available; and yet little discussion is devoted to it. However, with persistence and patience, information is to be had. Being the very opposite of an expert, in order to unbewilder myself I've gathered up a few options and laid them out over the next few posts. I hope that people will comment if I have made any gross errors or omissions, or if I have overlooked a system's advantages or drawbacks. This should make my decisions easier.

 

To come: 2. The First Principle, and what I ruled out.

[woodbine]

2. The First Principle.

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post.

 

To activate a signal arm a rod has to be moved up and down by a small distance. This outwardly simple task has produced quite an amazing variety of ingenious solutions. I will try to outline some of the main strategies that I've come across here and elsewhere, and recognise too that there are many differently detailed ways of fulfilling those strategies, depending on individual ingenuity. The links that follow in this series may not individually be the complete answer for you, but each of them I hope will contain a useful tip,  trick or technique.

 

I ruled out several routes early on, though some people use them. I repeat, I have no experience of these methods and am only going by the feeling given off by reading other opinions on the forum. I offer them anyway, they may be what you're after. Some may passionately defend them, please do, but I would prefer not to be flamed in the process so keep it reasonable.

 

Solenoid motors have a reputation for being noisy and violent, though they are used. They certainly work, even if they aren't perhaps as gentle as the real thing.

 

Here's another approach.  

 

I also ruled out Viessmann Motors on expense grounds

and

 

and Blue Point are also too expensive for me. Tortoise, and Fulgurex are variously unsuitable. Memory wire has gone out of fashion, it seems overly complicated and subject to temperature fluctuation, but for the curious here's a link to one way of using it.

https://www.scalefour.org/resources/signalsmemorywire.html

 

So what's left?

 

To come: 3. Manual Operation

Edited March 3, 2021 by woodbine
Added link to Joe MCMLXI

[woodbine]

 

3. Manual Operation.

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post.

 

The simplest, most direct solution is a more-or-less permanent physical connection, from somewhere convenient at the baseboard edge, to a bell crank, using a stiff rod, bicycle spoke, wire-in tube, or umbrella arm.

 

This can be routed round corners using further bell cranks. Alternatively the same can be operated using wire in tube, for example Mercontrol. http://lytchettmanor.co.uk.websitebuilder.prositehosting.co.uk/lytchett-manor/mercontrol---point-control

 

The motion can be taken across baseboard joints using various methods, such as (there are others if you search enough)

 

 

and

 

 

A fishing line system is also available from Ratio. https://peco-uk.com/products/remote-control-for-signals

 

31A in his previous post in this very thread has modified this by adding a pendulum under the crank to create the "signal bounce" effect. He operates this via fishing line, with gravity and the pendulum returning the arm.

 

 

So far I have avoided the topic of demountable, removable units, to which I will return after discussion of servo-driven mechanisms.

 

To come: 4. Operation by Servo - Mounts and Linkage

Edited February 10, 2021 by woodbine
Added NB.

[woodbine]

4. Operation by Servo – Mounts and Linkage

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post

 

Servo operated signals are the main alternative to manual operation among the professionals I believe. They are compact, economical, and reliable. In the unlikely event that a servo should fail they are easy and cheap to replace. The vertical signal operating rod is attached by some method to a crank as before, but this crank is part of the servo unit and can be minutely adjusted for distance, speed, and bounce. Mounts can be DIY or commercial. Some signals here can be made removable along with the servo, but there will also be a separate post specifically about removable mechanisms, both manual and servo controlled.

 

A DIY wooden servo mount with a ground signal.

 

See Portchullin Tatty's home-made mounts in his post above of Jan 8th.

 

John Fitness on his 10 years long thread custom builds his brass servo mounts to fit the circumstances. Two different ways on this page from 2011. He also seems to just as happy to stick them to the underside of the mounting plate where there is room to do so.

 

 

Here are some of Steve Hewitt's plywood mounts fixed in position on a customer's layout.

 

 

Here's EIGHT servos mounted together on a DIY mount, and various developments on the theme using aluminium.

 

 

Here's a Merg servo mount slightly adapted.

 

There is a useful range of printed servo mounts by Gwyn-c-emrail on Ebay.

Here.

 

Servo signal operation by moving a lever. http://www.lbscrmodels.co.uk/runsigs1.html

 

Servos need some electronics, which I will deal with next time.

 

To come: 5: Servo Controllers

Edited May 11, 2021 by woodbine
Added Gwyn-c-emrail

[woodbine]

5. Operation by Servo - Servo Controllers.

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post.

 

To operate the servo motor itself, you need a piece of electronics called a servo controller, a means of programming it, and a power supply.

They can be programmed to make the signals "bounce" realistically. Available from the following, along with advice and instructions

 

MERG controllers, self-assemble from a kit. https://www.merg.org.uk/merg_resources/servos.php

 

Megapoints ready-made controllers. https://megapointscontrollers.co.uk/?v=79cba1185463

 

GF Controls ready-made controllers. http://www.gfcontrols.co.uk/index.php/8-way-semaphore-unit/

 

Heathcote Bouncing Semaphore Controller. https://www.heathcote-electronics.co.uk/bouncing_semaphore_controller.html

 

There may be others, please add them if you have a link.

 

 

Embedded Conrols is a name that crops up in early posts, but doesn't appear to have made it into commercial production.

 

ESU Switch Pilot is available, but I don't know anything about their suitability. http://www.esu.eu/produkte/switchpilot/

 

 

To come: 6. Removable Signals

Edited February 17, 2021 by woodbine
Added Embedded Controls and ESU Switch Pilot

[KingEdwardII]

There is the Digikeijs DR4024 DCC servo controller:

 

https://www.digikeijs.com/en/dr4024-4-channel-servodecoder-with-4-additional-switching-outputs.html

 

...controls 4 servos using DCC commands

[KingEdwardII]

& I have come across another DCC servo controller which seems exceptional value:

 

https://chesterfield-models.co.uk/product/arduino-dcc-sniffer-relay-servo-decoder-all-in-one-copy/

 

...controls 16 servos using DCC commands.

[woodbine]

6. Removable signal posts.

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post.

 

Some signal posts can be removed from the layout without having to be disconnected from anything below the surface, some require a little bit of under-baseboard disconnection.

 

If I have missed a proprietary product please add it along with a link if you can find one, along with a brief description. Likewise if I have missed something that works on a different principle, a link would be good.

 

The Alan Gibson/Graham Warburton weighted rod system. You have to figure out how you actuate it for yourself, probably pushed up by a cranked paddle, or a lever, either manual or servo –driven. As it stands it operates to pull the drive rod down by gravity, but putting the weight on the other end of a crank or lever from the paddle could reverse the effect. http://www.alangibsonworkshop.com/Signal Construction.pdf

 

On the same principle, Wizard Models have come up with a weighted paddle, (SM5) which moves the wire, returning it by gravity, and allowing the whole mechanism to be withdrawn instead of just the drive rod. This can be actuated by WIT, Servo, stiff rod or whatever you like https://www.wizardmodels.ltd/shop/signals/sm5/

 

Here a wobbly pendulum has been added to give it some "bounce".

 

 

Steve Hewitt produces signals that slot into the base board and can be removed by disconnecting the rod from the servo. The intention is to connect them in a removable way to servos which remain mounted in his DIY mounts.

 

 

This picture if the underside without the servo shows that the method could also be adapted to manual operation.

 

 

And here it is applied to a ground signal.

 

 

Mark Tatlow, who posted above, has this useful guide, including illustrations of his removable signals with home-made servo mounts. http://www.clag.org.uk/tatlow-signalling.html

 

The similar, slightly larger, Wizard Models MSE SG90-1 servo mount includes a base plate for the signal. Also available for more than one servos. https://www.wizardmodels.ltd/shop/signals/sg90_1/

 

Jurassic Lasercut Mounts allow you to remove up to two servos with the signal. I'm not clear what scale they're intended for as they look fairly chunky, nor whether they are still available as I couldn't find a website.

 

 

To come: 7. Moving Magnets

[woodbine]

7. Moving Magnet

 

NB. In the references click on the dateline in the blue box, not the white thread title, to go to the intended post

 

Moving a magnet allows removal of signal without having to disconnect anything. It seems a nifty idea; has anyone else tried it?

 

 

A more sophisticated version from Caley Jim using a crank, which of course can be actuated manually or by servo.

 

 

The same applied to ground signals.

 

 

Is this the ultimate? From David John, three blogs showing him developing the magnet theme.

 

 

 

 

 

 

To come: Well I think that's all for now.

Putting it all down like this has helped me see through the fog, and I hope others may find it useful too as a quick introduction to the different ways of operating semaphore signals. I have deliberately avoided detailed instructions in order to keep the thread within bounds; that stuff can be found elsewhere. If you know of some method or product that you think would be useful feel free to add it.

 

[woodbine]

Does anybody know anything at all about the "Masokits Signal Operating Gear", which I have come across as item 11.16/17 of their catalogue. https://traders.scalefour.org/masokits/ ?

 

The blurb says "Enables a signal to built on a mounting plate complete with a 'Bounce' mechanism, to be easily removed from the layout" etc.

 

But I can find no other reference to it any where on the interweb, neither text nor pics.

[Joe MCMLXI]

I have gone with the solenoid operation, pull to operate, spring return. Low voltage so quite gentle. The connecting wire to the arm is one piece, no linkages, then superglued to the end of the armature rod.. A bit crude, but it works for me... A little plate at the bottom of the armature, limits the return position, I use this to set the board horizontal.... joe

[Stephen Freeman]

Personally I have never found that using magnets for the servo horn connection very reliable. I much prefer to fit a bolt to the horn, 10 BA  I think and loop the rod round it, a securing nut is optional.

This photo may help show what I mean. The signal is located by means of telescopic  square brass tubes. The wires for the LEDs are connected to the servo power leads by means of a plug and socket. The motor mount is  a MERG product.

Edited November 22, 2023 by Stephen Freeman

[woodbine]

If anyone has been wondering whether I came to any conclusions and actually made some signals, well yes I did. I opted for manual operation via wire in tube and it all works surprisingly well, though it ties the operator to a fixed location for each signal (i.e. the particular hole in the front of the baseboard). Had I been younger and with more years to go I think I would have gone for one of the servo methods. I'm glad I made them removable as I can work on the layout without fear of knocking them over. Here's my thread about it. 

 

 

Edited November 29, 2023 by woodbine
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