Semaphore Signals - 4mm Scale (Mainly)

[Jon Fitness]

Lovely stuff Steve. Now I've had my L&YR fix for one terminus on our layout, I'm now tempted to do a few Ex LNWs for the other one.

JF

[beast66606]

Lovely stuff Steve. Now I've had my L&YR fix for one terminus on our layout, I'm now tempted to do a few Ex LNWs for the other one.

JF

 

Yes please John.

 

Nice job Steve.

[Steve Hewitt]

Now for the Ground Signal.

 

This is to be a single arm version and is based on the etch for the two arm version from Scale Signal Supply.

This is a link to an image of the etch I used when building the signal for Liverpool Lime Street: http://www.rmweb.co....ttach_id=101648

 

The double lamp housing was made first - a simple fold up of the etching:

 

The prototype single arm signal has casting which raises the lamp housing above the balance bearing to the height required.

This I represented with a small length of square section brass to which two wing will be attached later to give the characteristic profile. I turned each end of the brass section to allow it to fit into both the lamp housing and the bearing housing:

 

The lamp housing was centred and drilled with the 1mm dia hole needed:

 

 

Cut off the surplus lamp housing, then when its all soldered together you get:

 

The rear part of the arm etch is attached to its bearing shaft:

 

After polishing, the half etched front of the arm is attached:

 

The balance arm had its holes re-inforced to ensure smooth operation and longevity:

 

So here are the main components:

 

The back-blinder / crank has been left on the etch for now, until final assembly.

If it escapes there's no way I'll find it!

 

 

Here the "wings" have been added to the "main casting":

 

The signal has now been attached on its base plate and foundation tube - 5/16th in. dia this time:

 

 

 

 

Clean polish and painting next......

 

Steve.

[Steve Hewitt]

Everything got a coat of Halford's White Primer, then the main signal body was finished in Halford's Satin Black.

 

 

The arm was held by its shaft in a pin vice for all the painting process.

The overspray just washes off with a soak in Cellulose Thinners when its all complete.

 

 

 

At this stage I'd forgotten that the signal may be "passed at danger on routes to which it doesn't apply".

i.e. it should be Yellow not Red!

 

Having the main items painted, I could tackle the final assembly.

 

The Blinder/Crank was beefed up where it will fix to the arm shaft:

 

 

Then the operating wire could be fixed.

This passes up through the base plate to the balance arm, a right angle bend each side allow it to continue up to the Blinder/Crank.

Another right angle bend allows it to passes through the Crank and be terminated with a pinch of the pliers.

Once the arm and crank are correctly positioned, a quick touch of solder on a hot iron fixes the crank to the shaft, trim off excess shaft etc. and everything is complete above ground.

Moving the operating wire upwards, raises the balance arm and turns the crank, and vice versa.

 

 

Unfortunately, I've failed to get a clear shot of this.

Must try harder next time.

 

At this stage my error was pointed out to me, and a repaint resulted in this:

 

 

The servo was mounted "below ground" in such a way as to avoid underground obstructions indicated on a template from the layout owner.

 

 

 

I'll get a video clip of this and the other two signals as soon as possible.

 

Steve.

[Jon Fitness]

Wonderful! I'd struggle to do that in 7mm never mind 4mm..

Jon F.

[Steve Hewitt]

First a shot which shows (just about) how the operating wire is routed:

 

 

I've taken some video, but its taking for ever to process it onto YouTube. !!*f--***

 

Steve.

[Steve Hewitt]

Here at last are the video clips.

 

First the Starter Signal:

 

This is the Bracket Signal:

 

Finally the Ground Signal:

 

You can see the operating wire more clearly in this clip than in my still shot!

This video is a bit cruel, as the whole thing is only just over 1/2 inch tall.

 

Steve.

[micklner]

Excellent , is the "bounce" done by software?

[Steve Hewitt]

Excellent , is the "bounce" done by software?

 

Yes, is the quick answer.

 

A servo arm (horn) moves through an arc.

The position of the arm is determined by the bandwidth of the control signal.

The extremes of the position are set with a bandwidth of 1msec at one end, and 2msec at the other IIRC.

The control signal for controlling semaphore signals comes from a dedicated servo controller, such as the MERG Servo4, the Embedded Controls units or in this case the GF Controls unit.

These all use software to generate the control signal.

 

The speed at which the servo moves is determined by the speed at which the bandwidth is changed.

Adjustment of the controller is typically limited to changing the two end positions i.e. setting the bandwidth for the Danger and Clear positions of the signal.

The more sophisticated the software, the more realistic the movement of the signal arm can become.

 

See my topic on servos and controllers for more detail: http://www.rmweb.co....vo-controllers/

 

Hope this is helpful,

Steve.

[micklner]

Any idea why I am getting this on that thread? please

 

I’ve started this topic in order to answer questions arising in mikemeg’s superb thread “More Signals at Hessle Haven & Scarboroughâ€.

[beast66606]

Any idea why I am getting this on that thread? please

 

Its the character set, something still not quite right

[Andy Y]

Any idea why I am getting this on that thread? please

 

I’ve started this topic in order to answer questions arising in mikemeg’s superb thread “More Signals at Hessle Haven & Scarborough”.

 

It's a problem carried over from the database being transferred between servers. We're still looking for a fix which doesn't involve going back and editing everything!

[micklner]

Thanks for reply. Never noticed it on any other thread. Can it be amended by the poster ? I will then check my thread too.

[Steve Hewitt]

Time to start another signal.

This is for a very large model of Carlisle, to which I've contributed a few signals in the last few years.

 

The owner has provided this picture of the signal required:

 

Its a late style LMS bracket, with low mounted arms for sighting requirements.

The main stem is tubular steel, as are the signal dolls.

 

The model is to be servo operated with working lights.

 

Having drawn a schematic of the signal at 4mm to 1ft scale, and with frequent reference to Graham Warburton's excellent book on LMS Signals, I made a start:

 

First the trimmers with the sockets to take the dolls and the two brackets in which the "rocking shafts" will revolve:

 

The two sockets were turned from Brass bar and also ensure the two channel sections are correctly spaced and parallel.

The hole in each is drilled 1/8in to take the main stem and the sleeved-up bottom of the second doll.

The first doll will eventually be located in the top of the main stem.

 

This shot of the trimmers upside down shows the crude representation of the prototype socket, which in real life is a welded assembly of plates and tube with fins giving the taped profile.

 

The brackets to support the Rocking Shafts or Torsion Bars are7mm scale "Medium Handrail Knobs" opened out to 1/32in dia. to take the brass tube I'll eventually use for the shafts.

 

To facilitate the assembly of these components I used an off-cut of MDF, drilled 1/8 at the correct spacing with two drills in the holes.

The sockets were placed over the drills and the trimmers lined up and held for soldering.

 

More to follow.....

Steve.

[Steve Hewitt]

Next the dolls.

 

Both are almost identical, just the diameter of the lower sleeving is less for the left hand doll, which will fit inside the top of the main stem.

 

As shown this is straight off the assembly jig which I use to get the arm bearings and lamp brackets in the correct positions.

Bearing length will be reduced considerably at a later stage.

 

More later....

Steve.

Edited September 26, 2012 by SteveAtBax

[Michael Edge]

Nice to see this one under way Steve, don't forget that the arms on the LH doll can be fixed, that route doesn't exist on the layout.

[beast66606]

Hi Steve,

 

I don't know if you've noticed but both the distant arms are fixed (and the left hand one doesn't have a green spectacle) hence the inter-arm gap is smaller than normal

 

Bog Junction was always an excuse for some toilet humour, especially as the base has been repaired / strengthened to make it as strong as a brick shi house

[Michael Edge]

I didn't notice the fixed distants either, I think I'd better post all the other signal photos on RMweb before you get to build them.

Michael Edge

[Steve Hewitt]

Hi Steve,

 

I don't know if you've noticed but both the distant arms are fixed (and the left hand one doesn't have a green spectacle) hence the inter-arm gap is smaller than normal

 

Bog Junction was always an excuse for some toilet humour, especially as the base has been repaired / strengthened to make it as strong as a brick shi house

 

Thanks for pointing that out. I'd missed it.

Steve.

[Steve Hewitt]

Thanks for pointing that out. I'd missed it.

Steve.

 

Hi Mike,

 

I'll see you at the Manchester show all being well, and we can agree the spec for this and any other signals David will require.

The model is a bit further advanced than the stage I've documented on here.

 

I'm away from home at present, and won't be in the workshop for a few days.

Just spent the day in "Steam" at Swindon.

Not my favourite company, but the Museum is well presented, all the displays work and its not too expensive at £4.40 for oldies like me.

 

Steve.

[Highlandman]

This is a great thread and I look forward to more regarding the construction and operation of model signals.

[Tongue in cheek] Have you thought about offering your services to produce a Right Track video about building model signals and the methods of operating them. I'd buy it. :-)

[Jon Fitness]

This is a great thread and I look forward to more regarding the construction and operation of model signals.

[Tongue in cheek] Have you thought about offering your services to produce a Right Track video about building model signals and the methods of operating them. I'd buy it. :-)

So would I !!!!

JF

[trustytrev]

Hello,

How do you do the see through glazing on the arm spectacles in 4mm please?

trustytrev.

[Steve Hewitt]

This is a great thread and I look forward to more regarding the construction and operation of model signals.

[Tongue in cheek] Have you thought about offering your services to produce a Right Track video about building model signals and the methods of operating them. I'd buy it. :-)

So would I !!!!

JF

 

Thanks for your comments.

I haven't thought of a video, but Phil Atkinson of Hobby Holidays has asked me to run a weekend workshop on Signal Construction and Operation for him.

The dates will be April 6th & 7th, 2013 if you're interested.

 

Steve.

[Steve Hewitt]

Hello,

How do you do the see through glazing on the arm spectacles in 4mm please?

trustytrev.

 

I use the appropriate glazing material from Model Signal Engineering.

 

For round spectacles, I use a "leather punch" to cut circles of the correct size.

For other shapes, I scribe the inside of the spectacle onto the glazing sheet, using a very sharp scriber.

This is then trimmed to size, a little at a time, using a small pair of needlework shears.

 

The glazing is secured in the spectacle with "Canopy Glue" from a model aircraft shop.

 

Steve.