Mid-Cornwall Lines - 1950s Western Region in 00

[St Enodoc]

The next job is to build the signal structure itself.

 

There are three parts - the base, the stand (which includes the lamp housing) and the weight bar.

 

The stand is narrower than the lamp housing, which is as it should be, but to make this a working model we need to beef things up a bit.

 

 

For this, I make two "cheeks" from 20 thou black styrene. The cheeks fit on the front and back of the stand next to the lamp housing, to give more support to the spindle when it's fitted.

 

 

Fixing the stand in the base is next.

 

The structure also now needs to be left to harden off before doing any more work on it.

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

I added the weight bars, which need the slot in the stands to be fettled slightly otherwise you're guaranteed to break the weight bars when you try to force them in (Voice of Experience). I got as far as fitting one disc but no photos as the light had gone and it's too dull this morning. I'll see what I can do later.

[St Enodoc]

Right, it brightened up enough at morning tea time to take a couple of photos.

 

This is the fiddliest part of the whole job. First, drill through the cheeks and the stand with a no 73 drill for the spindle. On the front of the stand moulding, next to the lamp, is a little dimple to start you off. I've no idea whether that is its intended purpose but as it's in the right place that's what I use it for.

 

Next take a short piece of 0.5mm wire. I use offcuts from building other signals. You need to make a very small loop in one end. I start with some very fine round-nose pliers, then complete the loop by squeezing it up against a piece of the same wire. Snip off the excess and press the loop flat.

 

The throw of this wire crank needs to be as small as possible, which means that the loop needs to be as close to the lamp housing as it can be without restricting the movement of the operating wire. Bend the wire crank at 90 degrees and poke it through the hole from the rear. Now go and have a cup of tea or read the paper before the next step.

 

Fixing the disc to the wire is probably the weakest link. There's no way that I've found to get a good bearing surface to glue to and of course you can't solder it or the whole plastic signal would melt. What I do is to drill a no 77 hole in the centre of the disc and press it on to the wire until it is flush. Because the hole is slightly smaller than the wire, and the end of the wire will have a burr from cutting it, it should hold itself in place while you use your third hand to put a drop of cyano on the joint. When the arm is On the loop in the crank should be in its lower position. I do all this before putting the stripe on the disc so that the transfer will conceal the end of the wire.

 

Having got this far, you've reached the Golden Mile, because once you're there you're laughing.

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

On 04/10/2020 at 11:59, St Enodoc said:

I've found a local supplier:

 

https://core-electronics.com.au/adjustable-switching-power-supply-module-in-4v-35v-out-1-5v-30v-lm2596s.html

 

and emailed them with a couple of questions, namely:

 

- the specification states that the voltage is regulated to within 2.5%. Is this 2.5% of the set value (i.e. 1.4V) or 2.5% of the maximum output voltage of 30V?

- there is mention of a heat sink for high current applications. I might need to operate up to 10 signals at a time, drawing about 2.5A. Is there a suitable ready-made heat sink or do people just make their own?

 

If their response is encouraging, I think I'll get one to try out. In the meantime, can anyone here with experience of using this type of device add to my knowledge?

Core Electronics have responded very quickly and positively. The tolerance is on the set value, which is what I wanted to hear, and they supply a suitable heat sink to sit on top of the IC chip. On that basis I'll order one of each.

[Barry O]

46 minutes ago, St Enodoc said:

Core Electronics have responded very quickly and positively. The tolerance is on the set value, which is what I wanted to hear, and they supply a suitable heat sink to sit on top of the IC chip. On that basis I'll order one of each.

That is why I is a Control Ingeneer mate! Them wobbly volte and amps are no problemo!

Baz

Edited October 6, 2020 by Barry O

[St Enodoc]

2 hours ago, St Enodoc said:

Core Electronics have responded very quickly and positively. The tolerance is on the set value, which is what I wanted to hear, and they supply a suitable heat sink to sit on top of the IC chip. On that basis I'll order one of each.

Order placed. Watch this space.

[St Enodoc]

The first batch of three ground signals is now complete, apart from attaching them to their actuators and installing them on the layout. The broad white band is a label with the signal number on it. There's another on the actuator so they can be matched up - the holes are not jig-drilled!

 

The red stripe is cut from another Modelmasters transfer, this time the red bands that denote catering accommodation on coaches (pack 4458R). You can see how the signal is off-centre on teh base, so that the operating wire can come up through one of the pre-moulded holes.

 

At the back I paint the operating crank white so the signalman can see whether the signal is on or off.

 

When the actuator is fitted, there will be enough movement to see clearly that the signal is off, even if it isn't the full 45 degrees. I don't bother glazing and colouring the spectacles, as they're too small to show up (I do need to pierce the transfer with a pin for the On spectacle though).

 

The white on the crank is also now at an angle.

 

At the same time as making these I made up a static dummy for St Enodoc, so that's another off the list.

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

Here's the starting point for the banner repeater:

 

I'll try to use as much of the Bachmann model as possible but until I start I don't know how practicable that will be in terms of cutting and drilling the resin from which it's made. If necessary I'll use the MSE parts to fill the gaps (possibly literally...).

 

Comparing the two and the drawing in Adrian Vaughan's GWR Signalling book suggests that the Bachmann head is slightly over-sized. That's actually not a bad thing, as most of the operating team are at the stage of life when moving to 7mm is often contemplated (one or two have already gone that way!), as it will make it easier to see. That's important, as it is the substitute for the section signal on the Down Main and as such will need to be obeyed by trains leaving the scenic area towards Penzance.

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

I installed the three ground discs on the layout this afternoon but didn't connect them electrically, as the new voltage regulator hasn't arrived yet.

 

 

Only one blue capstan left in this area now. This will become a 4ft stop arm with a 2ft Calling On arm below it (52/48 signals, the Up Main Starter). I've never built one before so that will be fun.

Edited July 17, 2023 by St Enodoc
images restored

[5BarVT]

9 hours ago, St Enodoc said:

Here's the starting point for the banner repeater:

Watching with interest as I will have one to do (eventually).

 

1 hour ago, St Enodoc said:

but didn't connect them electrically,

Before you do, I suggest you check the voltage across an operated signal from the dry cell. It may well be somewhat less than 1.5V due to the internal resistance of the cell.  If so, you will probably want to imitate that in your relay drive.  (Don’t want any more loss of memory wire!)

Paul.

[St Enodoc]

13 minutes ago, 5BarVT said:

Watching with interest as I will have one to do (eventually).

 

Before you do, I suggest you check the voltage across an operated signal from the dry cell. It may well be somewhat less than 1.5V due to the internal resistance of the cell.  If so, you will probably want to imitate that in your relay drive.  (Don’t want any more loss of memory wire!)

Paul.

Thanks Paul.

 

I'll measure the voltage tomorrow with different sizes of cell (AAA, AA and D, which I happen to have in stock) but I don't think it should be dropping too much, or the signals wouldn't be working when I test them with a battery. The theoretical voltage across the signal for my set-up is 5.5 ohm (the resistance of 70mm of 0.125mm memory wire) x 250mA (the optimum current for that size of wire) = about 1.38V. The signals should still operate down to about 200mA or 1.1V but more slowly as the wire will take longer to heat up.

 

At the moment, though, Plan A is to use the new voltage regulator that is in the post somewhere. When it arrives, unless the instructions tell me differently, I'll test it on open circuit and set the output voltage as close to 1.38V as I can. I'll then put a dummy load (5.6 ohm 5W resistor) across the output and check the voltage again. I might parallel up a few more resistors to simulate more than one signal being off at the same time too. I don't think there'll be too much resistance in the connecting wires.

 

If that's successful, I'll use the VR to power all the Porthmellyn Road signals. I think, although I haven't tested it on the lever frame yet - perhaps another job for tomorrow - that there can be a maximum of 11 signals off at a time, although that would be unusual. They will draw 250ma x 11 = 2.75A, which is within the VR's rated capacity of 3A.

 

If not, I'll go back to Plan B with the Duracells.

[St Enodoc]

On 09/10/2020 at 20:10, St Enodoc said:

I'll measure the voltage tomorrow with different sizes of cell (AAA, AA and D, which I happen to have in stock) but I don't think it should be dropping too much, or the signals wouldn't be working when I test them with a battery.

First of all, and with apologies to my friends in Victoria, this was a nice surprise today:

 

Anyway, when we got home after supporting today's charity and buying more L-girder timber, I tested a signal actuator with three different sizes of battery. All were brand new, straight from the pack. I didn't bother to measure the open circuit voltage (actually, I forgot) but the results under load were:

 

AAA - 1.42V

AA - 1.50V

D - 1.57V

 

I think this is what I would expect, in that the smaller batteries have the lowest capacity and hence the highest internal resistance - does that sound right Paul @5BarVT?

 

All three batteries operated the actuator without any problems so, in the event that the new voltage regulator doesn't do what I'm expecting, the battery fall-back option should be OK.

 

After that I made up the Polperran L-girders. The overall length is 3900mm but the timber only comes in lengths of 2440mm, so I cut the lengths in such a way that will maximise the number of magazine shelves that can be stored under Polperran. That meant one pair of L-girders at 1650mm, which will accommodate two shelves, and one pair at 2250mm, which won't quite accommodate three. I'll arrange the leftover space to provide an emergency duck-under between Porthmellyn Road and Penzance/Polperran.

 

I glued and screwed the L-girders but once the glue is dry I'll take the screws out so that there's no risk of them getting in the way later.

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

Last night, suitably fortified by a piquant Bl00dy Mary, I started the banner repeater.

 

 

The first job was to remove the permanently-fixed Bachmann arm. Pleasingly, this just popped out and left only a small mark that I sanded away. Next, I drilled the hole in the head for the spindle (no 73, as for the ground discs) and two more holes, one in the base and one in the platform, to guide the operating wire. The size of these isn't critical, although you don't want the wire to wobble about too much.

 

As is often the case with resin models, the "flat" base isn't and, while I was holding the signal to drill it, the rear ladder came unstuck at the top. No matter, it can be reattached later.

 

I'll attach a Ratio operating tube under the base in the usual way to mount the actuator.

 

Due to the more restricted space at the back of the head, I'm taking a slightly different approach to the crank mechanism from that on the ground signals. The loop will be on the vertical rod and the cranked end of the spindle will just be plain wire. I can bend this after assembly, so for strength I soldered the arm to the spindle this time. I actually used the MSE etched arm, since it was already pierced for the spindle. Behind the arm, you should just be able to see a 16BA nut that I also soldered in place, as a spacer. There'll be another (or two) behind the head, but not soldered, for the same reason.

 

I'm really making this up as I go along, so it could still all go t!ts up. The key bit will be getting the operating rod/crank relationship right. If all else fails, I could either make up the MSE kit in full or buy another Bachmann signal and try something slightly different.

 

Wish me luck.

Edited July 17, 2023 by St Enodoc
images restored

[5BarVT]

23 hours ago, St Enodoc said:

I think this is what I would expect, in that the smaller batteries have the lowest capacity and hence the highest internal resistance - does that sound right Paul @5BarVT?

That sounds right to me.  I think that your PSU solution is going to work.

 

3 hours ago, St Enodoc said:

As is often the case with resin models, the "flat" base isn't and, while I was holding the signal to drill it, the rear ladder came unstuck at the top. No matter, it can be reattached later.

Shame it wasn’t the front ladder: a front ladder says LMR 60s to me, I don’t think (G)WR went in for them.  I’m also not sure about the platform: is it too late to adjust the form?  I can’t find any photos quickly at present to confirm or deny.

i can’t remember if I’ve pointed you to Hornsey Broadway for a working MSE banner.  I saw it in Glasgow in Feb and was most impressed.  Wobble has put photos on his thread (top of page 9).

Paul.

[St Enodoc]

30 minutes ago, 5BarVT said:

That sounds right to me.  I think that your PSU solution is going to work.

 

Shame it wasn’t the front ladder: a front ladder says LMR 60s to me, I don’t think (G)WR went in for them.  I’m also not sure about the platform: is it too late to adjust the form?  I can’t find any photos quickly at present to confirm or deny.

i can’t remember if I’ve pointed you to Hornsey Broadway for a working MSE banner.  I saw it in Glasgow in Feb and was most impressed.  Wobble has put photos on his thread (top of page 9).

Paul.

Thanks Paul. The PSU should arrive this week. Until it does, further electrical work on the signals is on hold.

 

Good point about the ladders. I might pull the front one off deliberately based on that. The whole model seems to be a fairly generic mish-mash but that doesn't worry me too much. If I wanted accuracy I'd build one with a separate lamp. The platform is certainly very basic. Once the thing's working I might be able to titivate it somehow.

 

Yes, I've seen Kier's banner repeater although only in photos. It does look the part. I think his operating wire goes down the tube (so to speak) whereas mine won't, as the tube is a rod. I think he's glazed his too. I'll try but I reckon my skills would make it look worse than unglazed.

[St Enodoc]

42 minutes ago, St Enodoc said:

Good point about the ladders. I might pull the front one off deliberately based on that. The whole model seems to be a fairly generic mish-mash but that doesn't worry me too much. If I wanted accuracy I'd build one with a separate lamp. The platform is certainly very basic. Once the thing's working I might be able to titivate it somehow.

Vaughan has a drawing of a banner repeater with separate lamps and two ladders (Plate 75) but I think that might be because it repeats a home and a distant. Plate 76 underneath seems to show a single ladder but at the side.

 

A quick Google (other search engines are available) suggests that a single ladder at the rear is most common, so Ill follow your advice. Regarding the brackets, these seem to be two C-section beams with a gap between them. These will be hard to represent on the Bachmann model, so I think I'll just paint the sides of the platform white and the top, bottom and ends black. That will be good enough for me.

[Clive Mortimore]

Hi John

 

Don't forget he GWR banner repeaters were lower quadrant.

[St Enodoc]

50 minutes ago, Clive Mortimore said:

Hi John

 

Don't forget he GWR banner repeaters were lower quadrant.

Yes, that's right Clive. If you look at the photos you will see that pushing the operating rod upwards will move the arm anti-clockwise looking from the front, in just the same way as the rest of the signals.

[5BarVT]

1 hour ago, St Enodoc said:

Vaughan has a drawing of a banner repeater with separate lamps and two ladders (Plate 75) but I think that might be because it repeats a home and a distant. Plate 76 underneath seems to show a single ladder but at the side.

There was also discussion on this thread with photos of two WR banners, both have ladders front and back, but both were also  (at one time) repeating stop and distant.  There is a good closeup of the support for the HW one.

I also scanned through the recent GWS book but didn’t find any banners.  There were a couple of speed signs that had ladders front and back but they are considerably deeper and it was probably a stretch too far to reach the front for cleaning.

It has occurred to me that I’m not sure if I’ve seen a WR semaphore banner in the flesh so I may have been recalling 60s MAS practice when I first commented.)

Paul.

Paul.

[St Enodoc]

8 minutes ago, 5BarVT said:

There was also discussion on this thread with photos of two WR banners, both have ladders front and back, but both were also  (at one time) repeating stop and distant.  There is a good closeup of the support for the HW one.

I also scanned through the recent GWS book but didn’t find any banners.  There were a couple of speed signs that had ladders front and back but they are considerably deeper and it was probably a stretch too far to reach the front for cleaning.

It has occurred to me that I’m not sure if I’ve seen a WR semaphore banner in the flesh so I may have been recalling 60s MAS practice when I first commented.)

Paul.

Paul.

What an interesting thread. Having scrolled through it, I now think I'll leave both ladders in place and add a white finial (I've got a number of spare Ratio ones).

 

Thanks.

[St Enodoc]

On 09/10/2020 at 20:10, St Enodoc said:

I think, although I haven't tested it on the lever frame yet - perhaps another job for tomorrow - that there can be a maximum of 11 signals off at a time, although that would be unusual.

I had a go at this today and I think I was right. The maximum number of signals that can be off at the same time (excluding the distants 1 and 54, which are not modelled) is:

 

Through train on Down Main: 2, 3, 4, 6 = 4

Through train on Up main: 53, 52, 49 = 3

Departure from Platform 3 to Down Branch: 8, 9 = 2

Arrival from Up Branch to Loop, proceeding into No 1 Spur: 43, 25 = 2

Total = 11.

 

I reached this total in a couple of different ways but couldn't find any combination of routes that needed 12 signals to be off at the same time.

[St Enodoc]

19 hours ago, St Enodoc said:

add a white finial

Actually, I won't - because the configuration of the Bachmann model means that there's nowhere to put the extended post and finial. Authentic or not, it will stay as it is.

[The Fatadder]

Really like the look of this ground signals, though I dread to think how many of them you need to build.   One of my jobs for today is going to be gluing my non working signals into place on the layout, eventually they will get replaced with working ones but it’s way down the list given how unappealing doing the same fiddly job 10 times over sounds....

[St Enodoc]

17 hours ago, The Fatadder said:

Really like the look of this ground signals, though I dread to think how many of them you need to build.   One of my jobs for today is going to be gluing my non working signals into place on the layout, eventually they will get replaced with working ones but it’s way down the list given how unappealing doing the same fiddly job 10 times over sounds....

Fewer than 20 for the whole layout, Rich, of which about a third are already done. Doing something 10 times is off-putting but if I do three at a time with other things in between I find it OK.

[The Fatadder]

6 hours ago, St Enodoc said:

Fewer than 20 for the whole layout, Rich, of which about a third are already done. Doing something 10 times is off-putting but if I do three at a time with other things in between I find it OK.

I will have to give it a go and see how I get on in that case, the majority are hidden away on the main at the far side of the layout, but the 4 at the front of the layout probably ought to be working.  At any rate the step by step is bookmarked.