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Steve Hewitt

Semaphore Signals - 4mm Scale (Mainly)

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45 minutes ago, Harlequin said:

 

<Takes a deep breathe before questioning The Stationmaster because my knowledge is miniscule and mainly from books...>

 

The "Arm stop" in old pattern signals contained a sprung buffer to absorb the impact when the boss plate swung down onto it. That could explain a certain amount of bounce when arms return to danger, couldn't it?

 

(Ref: GWR Signalling Practice page 82.)

 

It was no doubt there to absorb the upward force, I doubt it could force back the down rod and balance weight.  And the centre pivot arms were well known for developing a 'notch' as a result of the stop arrangement used for some of them

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A quick YouTube search gave :

 

 

 

 

One example near the beginning and a second at about 3 minutes.

 

Steve.

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39 minutes ago, Steve Hewitt said:

A quick YouTube search gave :

 

 

 

 

One example near the beginning and a second at about 3 minutes.

 

Steve.

And in view of when it was filmed in relation to the end of availability of spare new parts and the availability of experienced S&T Techs etc I would put it down to poor maintenance & wear (note the down rod) and a Signalman(ler) throwing a lever back when he shouldn't.  Don't forget that spare parts for thse signals haven't been easily available, if you can actually get any, since Reading Works closed in the 1980s.

 

And if the Signalman had been one of mine  he would have been read his fortune for throwing signals back to danger like that although any decent local S&T Tech/Lineman (when they still existed) would have been a lot harder on him than I ever could be because worklng signals like that causes all sorts of unnecessary wear and damage (not just at the signal).

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There is however an error of the painting of the signal arm. Reference to the photo of the prototype will show what is needed to be altered.

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2 hours ago, The Stationmaster said:

It was no doubt there to absorb the upward force, I doubt it could force back the down rod and balance weight.  And the centre pivot arms were well known for developing a 'notch' as a result of the stop arrangement used for some of them

 

The spring ought to be fairly efficient at reflecting the energy that the returning arm/boss/rod/balance-lever system puts into it. That system has obviously been designed to move reasonably freely and balanced so that gravity isn't affecting one side or the other excessively. The chain/cable at the bottom would offer little resistance to the recoil, just slackening off.

 

So, to the naive imagination, a bit of bounce would seem quite natural if the signal man releases the tension in the cable faster than the system naturally returns to Danger - unless there's a damper in the Arm Stop itself. Hmmm... 

 

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10 hours ago, The Stationmaster said:

Far more common of course to see some hesitancy in the movement of a signal arm when it is being pulled off and a Signalman changes his grip on the lever or doesn't swing the lever steadily in the correct manner using his body weight to gain stroke on the lever.

Or it's a long run that needs a double pull to get it to activate the "Off" indicator properly?

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16 hours ago, Stephen Freeman said:

There is however an error of the painting of the signal arm. Reference to the photo of the prototype will show what is needed to be altered.

Thanks Stephen,

 

I've altered the arm.

 

Steve.

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Quote

That system has obviously been designed to move reasonably freely and balanced so that gravity isn't affecting one side or the other excessively.

Actually designed so that gravity returns it to danger if anything breaks, the balance weight has to be enough to pull the wire back from the signal box, the spectacle casting enough to put the arm back horizontal, and the down rod helps in that when its not broken. So definately not balanced!

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7 minutes ago, Grovenor said:

Actually designed so that gravity returns it to danger if anything breaks, the balance weight has to be enough to pull the wire back from the signal box, the spectacle casting enough to put the arm back horizontal, and the down rod helps in that when its not broken. So definately not balanced!

 

I realise it's biased to return to danger but it's set up so that not all the weight is on the danger side of the balance (if you see what I mean). That's what I meant by not affecting one side or the other "excessively".

 

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18 hours ago, Harlequin said:

 

I realise it's biased to return to danger but it's set up so that not all the weight is on the danger side of the balance (if you see what I mean). That's what I meant by not affecting one side or the other "excessively".

 

Not quite.   It's as 'Grovenor' said - GWR running signal arms were all constructed and arranged in such a way that the arm would return to danger if the down rod broke (because the spectacle plate was heavier than the arm),  Even the centre pivot arms would return to danger if a down rod broke broke because of the position and weight (which wasn't much as it happens) of the attached spectacle plate.  And I have proved the latter because it is exactly what the one I own does if I put something to act as an 'axle' through the pivot hole.

 

So yes, the arm itself obviously weighs something but that something is always less than the weight of the spectacle plate and any other ironwork on the spectacle plate side of the pivot (even without a back blinder attached).

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On 01/04/2020 at 23:10, Steve Hewitt said:

 

With the servo in Safe position, the arm is set to its corresponding mid position,

then the connecting tube is soldered to the operating wire.

It now just requires the signal arm adjusting to Danger and Clear using the GF controller.

 

I'll try to make a video of this shortly...........

 

 Steve

 

 

 

 

And here it is.....

 

 

 

 

Steve.

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Moretonhampstead signals completed.......

 

This Lockdown has allowed me more "shed time" than usual, so progress has been made.

 

I haven't many "work in progress" pics for this, but all the methods were consistent with the the Home signal.

If there are any questions please don't hesitate to ask....

 

Here are the completed signals on their transport & test frame.

P1040533.jpg.3ee7529a7500e7690b1abd0ed48d3d4e.jpg

All are in their "Safe" position, with the servos in mid-throw.

 

P1040552.jpg.b0f9d1f96f4012c8c8fec1be2fd1b855.jpg

The ground signals viewed from the other side.

 

A few details.....P1040540.jpg.d087d817e434bfc46e20376888add111.jpg

The advanced starter

 

P1040549.jpg.b80d086e5e691fb980d6b6ba81d79e02.jpg

One of the ground signals

 

P1040550.jpg.e065ddad81b61b28984d599af0f3377b.jpg

In the clear position

 

Finally, in the box, ready for delivery.

P1040556.jpg.2ca1b2d3889ecc6ff475457327b8805d.jpg

P1040557.jpg.0d4c736092fb0c4b270137a4382b65d9.jpg

The transport & test frame is made to be a tight fit when the lid is clipped in position.

 

Now its a matter of Delivery/Collection - whenever the Lockdown will allow.

 

Steve.

 

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With the Moretonhampstead signals off the bench, the next project can move forward, just 2 metres, .......

 

Starting with a photo of a "mock-up":

 Signal4.jpg.b787e794c4a160099deee64c9a236416.jpg

 

This has been developed into an early LMS style bracket with a lattice mainpost and tubular dolls:

20200426_094624.jpg.123fa25a82e5f384e1eb5ebb75d7821b.jpg 

First job is to prepare the components and sub-assemblies:

RIMG0111.jpg.ffe225c95388c03070586fadaa81c718.jpg

The Main Post from an Alan Gibson etch, with added angle corners

 

RIMG0109.jpg.1d0a2baf67886439e5aaaec83669dec6.jpg

Brass channel section Trimmers, drilled for the Rocker Shaft Bearings

 

RIMG0110.jpg.c0a37b235cc6da694a0c5010e622bfc8.jpg

The rocker bearings are 7mm scale Medium Handrail Knobs from Alan Gibson

 

RIMG0113.jpg.8188a0ffc28a6a3360422716b23ad3a7.jpg

Soldering the bearings in place, alignment ensured by a length of 0.8mm N/S rod.

 

The size of the lattice post , where the trimmers will attach, was measured and brass spacers turned to suit.

These are also to act as locators for the dolls.

To ensure everything is assembled in the correct position and vertical etc. a simple Jig was made from an off-cut of plywood.

Using the vertical mill, 2mm dia holes were drilled at the correct centres for the doll spacing - 6ft; 11ft and 6ft.

Silver steel rods (won't solder) were fitted into these holes and the brass spacers slid over them.

RIMG0112.jpg.56eb21bae6d721f4256d77f68d760923.jpg

The wooden jig with turned Spacers located at the doll centres.

 

RIMG0114.jpg.50b7e0e869bc336e618e1c8375dabc28.jpg

The Trimmers were clamped into position and soldered to the spacers.

 

 

More soon........

 

Steve.

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Posted (edited)

A few more steps.....

 

Continuing with components:

 

There are six arms, three to each side of the main post, so six weight bars. 

 

RIMG0116.jpg.52fb5bae84bcbdc8ee7a7c1429f93594.jpg

The bearings are fashioned from square brass tube.

The bars with weights at each end are for the "slotted" distant arms.

 

The Rocking shafts will transfer the wire pull across the trimmers.

Only two required to the left as the third arm will be connected directly to its weight bar.

 

RIMG0120.jpg.ef6cebd590aa54eb19a003aebab1e02d.jpg

The double rockers comprise concentric brass tubes with a 0.4mm "hinge pin".

The inner tube is 0.6mm dia, the outer is 0.8mm dia.

The longer single rocker is 0.8mm tube on a 0.6mm dia hinge pin.

The crank arms are cut from a Gibson  etch of tiny angle cranks.

 

The trimmers have been assembled to the post.

To ensure squareness, the wooden jig was drilled thru' to clear the post.

With the trimmers located by the silver steel rods, I secured my small engineers square to the underside of the jig and to the post.

With everything square the trimmers were soldered to the post.

 

RIMG0115.jpg.c262aa31ff8d52b8cc1b527cf1a5ffec.jpg

A bit of a lash-up, but effective.

Time to trial  fit the rockers.

 

RIMG0119.jpg.c51ae5931215786d24b2fd0dc1225c28.jpg

The 0.4mm hinge pin for the two double rockers.

The rocker bearings were sleeved down to the correct size - 0.4mm or 0.6mm by soldering in appropriate brass tube and trimming it with the piercing saw.

 

 

Hopefully, the following shots will show how the rockers are fitted:

 

RIMG0121.jpg.272954a3e10a38f6a4761eee0fb83a46.jpg

RIMG0122.jpg.391d9af349b07cb679c76f7ed18ea2c5.jpgRIMG0123.jpg.62520c4be8111522c07c69e689aaf4eb.jpgRIMG0124.jpg.dd7a08b2d772ca6140cd8ccfc8856a13.jpg

 

Finally for now, the brackets were made up from a M.S.E. etch.

 

RIMG0118.jpg.840f6f59b270a616df7204423cc5d9e7.jpg

With added strip to give depth to the "T" section part.

 

 

More soon.......

 

Steve.

 

Edited by Steve Hewitt
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Lovely stuff Steve. It's ages since I did any rocking shafts for signals as most of my commissions seem to be GW at the moment!

JF

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Wonderful work Steve!

I think you have just illustrated why us mere mortals will never be able to build signals like wot you can! :(

Tony

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Time to play with the Dolls............

 

The four dolls are made from 2mm o/d Brass tube, 1.5mm i/d.

The Finials are turned brass from Alan Gibson.

The Lamp/Bearings are 3D prints from Shapeways.  See Les Green's shop:  https://www.shapeways.com/shops/railway-odds-and-ends?li=pb

The shoes are resin mouldings, the 3D master is also available from Les's Shapeways shop.

From that you can make a Rubber mould, in which to cast your resin shoes.

 

RIMG0126.jpg.b4501922787629488ade3689b7da673e.jpg

The four dolls.

 

2040172746_RIMG0125-Copy.jpg.f14c59bf4822d1b8b2eccc9aeaa782cb.jpg

A trial fit.

 

It is necessary to provide a route for the Optical Fibres which will eventually pass from the Lamps, through the structure and down below the baseboard.

 

RIMG0128.jpg.dee656f86dcfce3235346f19fae0e80b.jpg

A hole below each Lamp and another where the fibres can exit.

 

RIMG0129.jpg.0887a6da64bc67500a79cea777fc6f6c.jpg

The fibre will need encouraging to exit the Doll, so a plug was turned for the bottom of the doll, with its top surface filed at an angle and positioned to deflect the fibre.

 

RIMG0131.jpg.4731ae7ae5fa70dc80df34820c397d35.jpg

Scrap fibres fitted to prove it works.

 

RIMG0132.jpg.70588e6c9db9bfcb9f30dcc7ecc1b022.jpg

The fibre passes through the lamp where the sharp bend will allow a little light to leak and represent the Backlight.

 

More soon....

 

Steve.

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6 hours ago, Steve Hewitt said:

Time to play with the Dolls............

 

The four dolls are made from 2mm o/d Brass tube, 1.5mm i/d.

The Finials are turned brass from Alan Gibson.

The Lamp/Bearings are 3D prints from Shapeways.  See Les Green's shop:  https://www.shapeways.com/shops/railway-odds-and-ends?li=pb

The shoes are resin mouldings, the 3D master is also available from Les's Shapeways shop.

From that you can make a Rubber mould, in which to cast your resin shoes.

 

RIMG0126.jpg.b4501922787629488ade3689b7da673e.jpg

The four dolls.

 

2040172746_RIMG0125-Copy.jpg.f14c59bf4822d1b8b2eccc9aeaa782cb.jpg

A trial fit.

 

It is necessary to provide a route for the Optical Fibres which will eventually pass from the Lamps, through the structure and down below the baseboard.

 

RIMG0128.jpg.dee656f86dcfce3235346f19fae0e80b.jpg

A hole below each Lamp and another where the fibres can exit.

 

RIMG0129.jpg.0887a6da64bc67500a79cea777fc6f6c.jpg

The fibre will need encouraging to exit the Doll, so a plug was turned for the bottom of the doll, with its top surface filed at an angle and positioned to deflect the fibre.

 

RIMG0131.jpg.4731ae7ae5fa70dc80df34820c397d35.jpg

Scrap fibres fitted to prove it works.

 

RIMG0132.jpg.70588e6c9db9bfcb9f30dcc7ecc1b022.jpg

The fibre passes through the lamp where the sharp bend will allow a little light to leak and represent the Backlight.

 

More soon....

 

Steve.

Realy impressive work here Steve..

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Posted (edited)

A few more steps......

 

Ladders:

I use etched ladders, reinforced with 0.4mm N/S wire on the stiles.

These are remarkably strong and avoid the "snakes" often seen on layouts where etches have been used without strengthening.

 

RIMG0136.jpg.a061dee43f85ba1b2a3f37c8b5e759b0.jpg

The carefully trimmed etch is folded at the end to create the fastening where a ladder will be fixed to a Doll.

The N/S wire is attached to the front of each stile, carefully aligning by hand and soldering a few cms at a time.

Asbestos fingers are a great help.

 

RIMG0137.jpg.a79bec1ab987349497002c35dbbe1669.jpg

I use a brass rod of 2mm square section to hold the ladder in the vide without crushing it.

(The flat etch is against the rear jaw, the half etch and wire to the front.)

 

RIMG0138.jpg.f4cc0b283bc2020b401a43caa9bdac2c.jpg

A very smooth file is then used to give a flat edge to the stile.

Don't file outside the portion supported by the vice.

 

RIMG0139.jpg.9734be4e644b31cafd0822731591ef6e.jpg

The result.

(I can never get a good result with wire thru' hole type ladders)

 

 

Next the staging.....

 

The horizontal beams represented by 1mm x 0.5mm brass strip.

Drilled at each end 0.45mm to take the lace pins I use for the stanchions.

 

RIMG0127.jpg.6cddd21b1e06372ac30579a7da55131b.jpg

The eight beams, the hole centres marked set out with dividers for consistency.

 

RIMG0140.jpg.cc6ba9599edc0226cffccdc58b7b3862.jpg

Soldered in place.

The front top edge of the trimmer was drilled to take the pins, which gives an excellent joint.

 

Time to put a foot down.....

 

Creating the foundations. The signal will stand on a N/S baseplate which will also anchor the lower ladder.

To help support the signal, it will be located by a turned brass spigot.

This will fit closely within the bottom of the lattice lost, and be hollow to for the optical fibres to pass through.

This turning also supports the baseplate which sits on a larger flange.

Below this flange a tube extends some distance. (Reason to become apparent).

 

RIMG0142.jpg.fb1c7d713246fc8746c31f12d59645e7.jpg

The turning.

 

The baseplate was marked out and drilled for the turning, ladder footings and the operating wires.

To locate all this on the layout, the whole is fixed to a 5/8in dia brass tube. (Larger than my usual 1/2in tube because of all the operating wires etc.)

 

RIMG0143.jpg.c0e27f32820031f429f44e6114ab925e.jpg

The various parts.

 

RIMG0144.jpg.ce256b076617867f5e3c8cb77c69b575.jpg

Soldering the turning to the baseplate, lots of flux and the blowtorch.

 

RIMG0145.jpg.ed0dc8a590af8fe9f8a355eb68031503.jpg

Similarly for the foundation tube.

 

Those who follow my methods will know I like to give the operating wires a good supportive route to their servo motors.

This starts with what I call guide tubes. These are lengths of 1/6th dia brass tube which fit through the baseplate and are supported inside the foundation tube. The operating wires will eventually be secured inside 1.32in tubes which will slide nicely within the guide tubes.

This minimises buckling etc.

 

RIMG0146.jpg.315f72c4c05a6b452128c031d1840a11.jpg

First three guide tubes being fitted.

 

RIMG0147.jpg.a6d1e519908f2185691f49a6c9843146.jpg

From below.RIMG0148.jpg.23474e3e4453d889eba4d24fd965cbb2.jpg

Almost complete.

 

RIMG0149.jpg.874fc94d579ea2b5df9f3aea5b4b12aa.jpg

The turning extends slightly beyond the foundation tube - so that it can be used to align the signal.

 

RIMG0150.jpg.3375b132f012f14623fe260fe8c26114.jpg

Supported in the lathe, the post is soldered to the baseplate/spigot.

 

Enough for now.........................

 

Steve.

 

Edited by Steve Hewitt
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If I may offer some advice to the master?

Re the laddering. Although I use etched stiles and rod for mine, this should work for you.

If you file down two long coffee stirrers, or similar bits of wood, to the width of the internal rungs between the stiles, place the ladder between them and clamp the whole assembly in either a pair of bending bars or, as in my case, a large hold and fold and solder on the n/s strip, you'll be able to work on a longer length of ladder. Also, it negates the need to remove the ladder from the jig to file and neaten the stiles.

Hope that makes a degree of sense.

 

Mike.

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Thanks very much Mike, much appreciated. 

Steve 

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Great craftsmanship, enjoying watching your skills on these pages.

 Cheers 

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Wow. The amount of engineering that goes into your signals still astounds me Steve! Lovely work as always and all power to your methods.

Wonderful:imsohappy:.

JF

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A little more.....

 

Having fitted the handrails - from 0.33mm dia N/S, and the tie bars to assist with the overhang, I couldn't resist a trial fit of the dolls again, to see how its going to look.

 

RIMG0151.jpg.eaa5f5e14ec26028cc85048ab7f88883.jpgRIMG0152.jpg.ddc6bfd7a88756d0289f23964c3d0089.jpg

 

More or less the last items to fit were the bearings for the weight bars.

RIMG0153.jpg.077307cf9686f8d7be45a48b23b53110.jpg

Obvious how they've been made from square brass tube.

This was just after a bath and scrub with Cif.

 

Degrease for everything and then off to the paintshop............

 

Steve.

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