Semaphore Signals - 4mm Scale (Mainly)

[Steve Hewitt]

Looks a nice structure, Is it an all tubular one?

JF

Hi Jon,

 

Yes its all "proper LMS" late series, round post.

 

 

 

Hi Steve.

I saw you at Warley, but you looked far too busy/popular to speak to!

It may be an illusion, but in the bracket signal photo, it looks as if the LH bracket joins the main post slightly higher up than the RH bracket. Perhaps because the taller doll results in a greater weight on the right?

Regards,

Dave.

 

Hi Dave,

 

Sorry I missed you at Warley - yes it was very busy for Rob and me on the demo stand.

I think the image is confused by another structure immediately behind the signal.

 

From my "guesstimates" of the loading, I think the bending moment on each side of the main post is about equal.

I used a figure of 1 unit for a miniature arm to 3 units for the Full size ones. If you multiply these by the distance of their dolls from the centre line, you get:

Right hand  1 x 7 + 6 x 3 = 25.

Left hand  1 x 3 + 3 x 7 = 24.

 

My calculations are purely based on guess work

 

Steve.

[Dave Holt]

Sound reasoning (and quite scientific). It must just be the angle of the photo or as you say.

Dave.

Edited December 17, 2016 by Dave Holt

[Steve Hewitt]

First steps......

 

The main structural feature of this signal is the bracket work which will hold everything in place.

It has to hold the dolls vertically and correctly spaced, and locate that lot on top of the Main Post.

 

I decided to make a simple "Jig" to assist me in making this part of the model.

It consists of a piece of Tufnol (I think) into which I've machined five holes.

I used the indexing table of my miniature milling machine to accurately space the holes for the Dolls and Main Post.

 

To facilitate making up the Trimmers and supports for the Post and Dolls, I made dummy items from Silver Steel:

 

 

The Tufnol and Silver Steel are quite heat and solder resistant, making them ideal jig material for the assembly process, of which more soon.........

 

Steve.

[RBAGE]

Can't wait.

 

Will it be ready for Santa to deliver to this address?

 

Bob

[Steve Hewitt]

Which year?

 

Steve. 

[Steve Hewitt]

The Trimmers.....

 

The Trimmers themselves are channel section brass, two pieces soldered back to back and cut to length and squared off.

Separated again to give:

 

 

To space these accurately and keep everything square I drilled and parted off these small sections of 4mm square brass bar:

 

 

The holes are 2mm for the dolls and 1/8in for the main post, and are reamed to be a sliding fit on the silver steel rods shown earlier.

 

The rear surface of the trimmers are already tinned where the two items had previously been solder together. Liquid flux, a hot iron with a largish tip and a little extra solder soon had the first trimmer assembled:

 

 

Repeating the process, ensuring the trimmers are in line, gives us:

 

 

This assembly is a smooth fit on the jig, and hopefully so will the dolls and post when they are assembled.

 

Limitted time in the workshop at this time of year, so the next instalment might be short while coming......

 

Steve.

Edited December 21, 2016 by Steve Hewitt

[Steve Hewitt]

Some more bits and pieces before assembly can start....

 

The bracket work on this type of signal is shown very clearly in Warburton's LMS Signal book.

The LMS No 5 Bracket is mainly fabricated from angle iron, and bent in one or two places.

 

Producing these from separate pieces can be a quite a challenge.

However my good friend Les Green produced some excellent etches in Nickel Silver for me some time ago:

 

 

Folded up on my "Hold & Fold":

 

 

We get:

 

 

Where the brackets attach to the Main Post uses two short lengths of channel section, clamped to the post, to which the brackets are bolted.

 

In 4mm scale these are represented by little pieces of Brass Channel, machined to fit the post so they are square and have enough surface area to take the solder.

 

This is how I machined them.

The stock channel is held in the machine vice:

 

 

The End Mill cuts down vertically through the sides of the channel:

 

 

To give us:

 

 

Two of these were produced, and left overlength.

Once carefully aligned and soldered in place they will be cut back until only a little over size.

Final trimming being done after the lower ends of the two brackets are soldered in place.

 

Of which, more later.....

Steve.

 

 

 

[Steve Hewitt]

More bits...........

 

The Rule 55 Diamond and the Bearings for the Weight Bars need preparing.

 

The diamond is an etch from MSE.

I used to solder these directly to the post, but recently I started making them with a slide-on mount which is a bit like the prototype strap:

 

First a little piece of 4mm square brass is drilled for the post the parted off in the lathe. About 0.9mm thick.

 

This is soldered to the rear of the etch, and the shape finished with files.

 

Ready to slide onto the Main Post at 12ft above rail height.

 

Next the Bearings for the Weight Bars. A similar technique, using a drilled section of 4mm square brass to which the Bearings are attached. These made from 4mm square Brass Tube, filed to shape.

 

 

The front and rear solid faces of the mounting have been opened up with a piercing saw.

 

A bit more work with the needle files will tidy this up so it will represent two bearings clamped to the sides of the main post. (Honest....)

 

The foundations for the signal are prepared in my usual way.

A turning locates the base of the main post, and guide tubes are provided for each of the operating wires. (That for the right hand miniature arm will be cosmetic - see note on drawing in previous post.)

 

 

From above:

 

 

To locate this in the baseboard, and ensure the servo assembly aligns correctly, this 5/8in dia Brass Tube is used:

 

 

Soldered underneath the base plate:

 

 

Assembly will follow.......

 

Possibly next year     - All the Best

 

Steve. 

 

 

 

 

 

 

 

[Steve Hewitt]

Assembling the bits...........

 

First, "A Happy New Year" to all who follow my ramblings.

 

Second, an apology for not having individual photos of all the assembly steps.

However, I will describe each of the steps and hopefully the photos I do have will suffice to make my ramblings clear.

 

First off, I attached the channel sections to the main post where the lower end of the No 5 Bracket will be fixed:

 

These are still a little overlength, and will be trimmed after the Bracket is fixed.

 

You will recall that the first item I made was the jig for holding all the main components in the correct relationship.

Having built the Trimmers and added the supports for the Rocking Shafts from 7mm scale Handrail knobs, the jig was next used to fix the Main Post and the Dolls.

 

In use, the jig sits on top of the trimmers, with the Main Post extending through the jig.

 

I remembered to add the cast "Shoe" to the main post, this being superglued in place later in the build.

 

 

The Dolls are cut to the correct length and located by the jig as they are soldered in place:

 

 

The assembly was then withdrawn from the jig and the extra length of the main post was cut back:

 

 

The No 5 Brackets were carefully located and soldered in place:

 

 

 

The Channel section mounts were then trimmed to the edges of the brackets.

 

Finally for now, the whole assembly was checked for vertical using the jig once again:

 

 

And that's all for now folks.............

 

Steve.

 

 

[Jon Fitness]

Exquisite design and build Steve. Engineering excellence in miniature.

Jon.

[Steve Hewitt]

Final static bits...............

 

First were the supports for the staging.

These are from 1mm x 0.5mm brass, cut to length and drilled for the stanchions (lace pins).

 

 

You can see the 0.4mm N/S wire added to anchor the bottom and top of appropriate ladders.

 

The cast resin "shoes" were glued in place on the dolls, then next I added the 3d printed Arm Bearings and Lamps:

 

 

The ladders were next:

 

 

Together with the Finials for the dolls which are a turning from Alan Gibson - excellent.

 

Not forgetting the stanchions:

 

 

I've decided on this signal to take a leaf out of Jon Fitness's book and leave the handrail until after painting - first time I've done this.

 

Now its time to say "Thank you" to Father Christmas....

 

Many years ago I bought a Badger grit blaster for cleaning up some of my less than tidy soldering, prior to painting. Being short of cash at the time, the compressor I bought was a cheapy, with no air tank. Consequently I had very limited success, and the grit blaster ended up at the back of a drawer for the last umpteen years.

 

A shiny new compressor, with Tank and 4-bar of pressure was in my Christmas Stocking.

What a revelation.....

 

Feeding the hose out of the workshop window, and using a wheely bin as the spray booth, it made very short work of cleaning up this signal:

 

 

 

The finish is smooth but dull and looks like it will take paint very well indeed:

 

 

A good hot bath in my ultra-sonic thingy with a strong solution of "Viakal" followed by a soak in Cellulose Thinners and then off to the Paintshop with the two "Home & Distants" I prepared earlier.

 

More soon.....

 

Steve.

 

 

 

 

 

 

 

 

[St Enodoc]

Final static bits...............

 

First were the supports for the staging.

These are from 1mm x 0.5mm brass, cut to length and drilled for the stanchions (lace pins).

 

RIMG1014.jpg

 

You can see the 0.4mm N/S wire added to anchor the bottom and top of appropriate ladders.

 

The cast resin "shoes" were glued in place on the dolls, then next I added the 3d printed Arm Bearings and Lamps:

 

RIMG1016.jpg

 

The ladders were next:

 

RIMG1017.jpg

 

Together with the Finials for the dolls which are a turning from Alan Gibson - excellent.

 

Not forgetting the stanchions:

 

RIMG1022.jpg

 

I've decided on this signal to take a leaf out of Jon Fitness's book and leave the handrail until after painting - first time I've done this.

 

Now its time to say "Thank you" to Father Christmas....

 

Many years ago I bought a Badger grit blaster for cleaning up some of my less than tidy soldering, prior to painting. Being short of cash at the time, the compressor I bought was a cheapy, with no air tank. Consequently I had very limited success, and the grit blaster ended up at the back of a drawer for the last umpteen years.

 

A shiny new compressor, with Tank and 4-bar of pressure was in my Christmas Stocking.

What a revelation.....

 

Feeding the hose out of the workshop window, and using a wheely bin as the spray booth, it made very short work of cleaning up this signal:

 

RIMG1020.jpg

 

RIMG1019.jpg

 

The finish is smooth but dull and looks like it will take paint very well indeed:

 

RIMG1021.jpg

 

A good hot bath in my ultra-sonic thingy with a strong solution of "Viakal" followed by a soak in Cellulose Thinners and then off to the Paintshop with the two "Home & Distants" I prepared earlier.

 

More soon.....

 

Steve.

Top work as always Steve. By the look of it the grit/Viakal/thinners process didn't harm the plastic parts. Did you need to take any special precautions?

[mark axlecounter]

Hi Steve,

I have been watching this topic for some time and what you have done is amazing I wish I had the skill you and John have keep up the good work.

 

Mark towers

 

[Steve Hewitt]

Top work as always Steve. By the look of it the grit/Viakal/thinners process didn't harm the plastic parts. Did you need to take any special precautions?

Hi,

 

No special precautions necessary.

The grit blaster is the most risky, so I try not to dwell on the resin and printed items.

 

Steve.

[Jon Fitness]

Looks a really nice finish and as you say, should take paint really well. What sort of pressure does to the grit blaster run at Steve? 

Might be worth fitting the handrail around the back of the signal and just leaving the front section to do after fitting the signal links!

Jon F.

Edited January 7, 2017 by Jon Fitness

[Steve Hewitt]

Hi Jon,

 

Not certain what the output pressure is, as the gauge measures the tank pressure, and there is a pressure valve in the line to the "gun".

However, I think it is fairly well open.

I do have an in-line gauge, pressure valve  somewhere which I'll try to fit and get an actual reading.

The tank pressure seems to stay between 3 and 4 bar, at which point the pump shuts down.

 

I planned to have the handrail in one piece, with just a single joint along the front, but I'll consider your advice.

 

Thanks,

Steve.

[Jon Fitness]

Thanks Steve, If it's running at a high pressure it'll probably only be limited to whether the pump can keep up! Does it just key the surface or will it take off excess solder without taking bits off with it?!

Ta

JF

[Steve Hewitt]

Thanks Steve, If it's running at a high pressure it'll probably only be limited to whether the pump can keep up! Does it just key the surface or will it take off excess solder without taking bits off with it?!

Ta

JF

Hi Jon,

Give me a day or two and I'll make a test piece up, try it out and photograph it for you.

Steve.

Edited January 8, 2017 by Steve Hewitt

[Highlandman]

Hi Jon,

 

Not certain what the output pressure is, as the gauge measures the tank pressure, and there is a pressure valve in the line to the "gun".

However, I think it is fairly well open.

I do have an in-line gauge, pressure valve  somewhere which I'll try to fit and get an actual reading.

The tank pressure seems to stay between 3 and 4 bar, at which point the pump shuts down.

 

I planned to have the handrail in one piece, with just a single joint along the front, but I'll consider your advice.

 

Thanks,

Steve.

Hi Steve

 

In regards to your compressor the working pressure is always slightly lower than the standing pressure. This is why you should set your pressure gauge with the air brush running. I would open up the inline valve to the max, hold down the trigger to your airgun and then set the pressure you want on the compressor. You will notice that when you release the trigger the pressure gauge will show a slightly higher reading. I hope I'm not "teach granny to suck eggs" and as usual the work you produce is amazing. I look forward to seeing the finished results.

 

All the best

 

AndyM

[Steve Hewitt]

Returned from the Paint Shop........

 

 

First job is the Rocking Shafts which transfer the pull of the operating wires along the trimmers to the dolls.

 

 

On the right hand side there are two linkages, for the Starter and the Shunt arms.

(The Distant is fixed).

The shunt arm won't be driven by a servo, but it is being modelled "cosmetically":

 

 

On the left side, I've only provided one rocking shaft, for the outer doll,

The inner doll will have the operating wire going straight to the arm.

There isn't room for even a short rocker because the components are necessarily over scale:

 

 

This is the outer end:

 

 

Next will be the fibre optics, then all the operating wires etc.

 

Steve.

[Jon Fitness]

Captured the look spot on Steve! Those doll shoes are superb, I'm going to have to re-master my cast white metal ones I think!

JF

[Steve Hewitt]

Too busy for many "process" photos, sorry..........

 

The fibres were threaded through all the structures (the bracket signal plus the two Home and Distants.

 

I continued to install the operating wires and the timbers of the staging on the first H&D, so it looks fairly complete:

 

 

The LED is a "Gas Light" from Helmsman as usual.

 

Here are a few more shots around this model:

 

 

 

 

 

 

 

I'll get the other two completed "from the ground up" then sort out the servo mounts.....

 

Steve.

 

 

[Steve Hewitt]

Upper work completed....

 

I had previously prepared a batch of Arms, Weight Bars, Blinders etc., so I quickly moved on to assembly:

 

 

 

Once all the moving bits were installed, I added the Handrails and touched up the painting:

 

 

Moving "below ground" I connected up the LEDs to the Fibres:

 

 

Installing the Servos completed the process:

 

 

Here they all are on their "Transport & Test Frame", ready for packing.

 

 

 

The space behind these signal on the frame is for the next two.......

 

Steve.

[Jon Fitness]

Cracking job as usual Steve! Leaving the handrails off until all the linkages are on does make it so much easier to connect things up too.

I keep forgetting how small these 4mm scale signals are (well, to me anyway!).

All the best

JF

[Steve Hewitt]

A brief sojourn to the Great Western............

 

Before starting on the next couple of signals for Carlisle, I need to build a GWR Round Post bracket signal, for which the eventual owner has been waiting far too long.

 

I've started by getting together most of the necessary components:

 

 

You will see that I've already made a sub-assembly of the bracket:

 

 

Based on an MSE etch, I replaced the Doll location top plate as the holes were not in the correct place, and were too large anyway.

The replacement top, and its identical twin lower item were made from off-cuts from an etch.

The size is such as to overlap the etched "angle work" so that there is an angle at top and bottom.

 

This view from the rear just shows the pivot for the operating cranks, made from 0.7mm dia brass tube.

 

This sub-assembly was put together on one of my "Tufnol & Silver Steel" jigs, itself made on my mini-milling machine. The indexing table makes accurate spacing of the holes a fairly simple matter of counting the turns of the handle.

 

The other components I made:

 

This the pair of Wire Cranks which will be located near the bottom of the main post.

 

This little item will anchor the lower end of the "T-section" truss to the Main Post.

 

One of the three 12inch Angle Cranks I prepared.

 

This is the Weight Bar for the R/H. Doll with its bearing and post fitting.

 

And that for the L/H Doll, put together with a lace pin for a pivot.

The Weight Bars are David Geen etches - very fine indeed. I hope I can attach the operating wires without destroying them. Time will tell.

 

This is a 3D printed Lamp & Bearing being tried out on one of the Dolls.

 

The two arms, assembled from MSE etches.

 

And their Back Blinders.

 

Here is the foundation Tube which locates the main post -

 

 in this Base Plate.

 

Finally for now, the Cap on the top of the Mian Post.

 

Next, to put it all together............

 

Steve.