Mid-Cornwall Lines - 1950s Western Region in 00

[St Enodoc]

8 hours ago, Tallpaul69 said:

Sounds like you are making good progress on the foundations for the branch!

 

Can we have some pics before you hide the infrastructure with the baseboards? I for one will understand better what you have been doing with some pics. And maybe a plan of the branch and how it relates to the rest of the layout (apologies if you have posted these before, just post the relevant page nos.)

 

Best regards, from a soggy UK,

Paul

Thanks Paul. I'll take a photo this weekend and post a little bit more about the branch too.

[St Enodoc]

On 03/10/2020 at 08:48, St Enodoc said:

Thanks Paul. I'll take a photo this weekend and post a little bit more about the branch too.

Here's the block plan of the layout:

 

At the moment only the Paddington and Penzance storage loops, Porthmellyn Road station and the double track main lines round the room are operational. The branch line will leave Porthmellyn Road and turn 180 degrees to the right, passing through St Enodoc station (based on Bugle). It then turns 180 degrees to the left and, after passing Wheal Veronica china-clay dries and Indian Queens Halt, approaches the triangle at Treloggan Junction (based on Tolcarn Junction). Finally it turns a further 180 degrees to the right to finish at Pentowan (based on Newquay).

 

The two other legs at Treloggan Junction converge and disappear into Polperran fiddle yard, which represents not only the Chacewater line but also, for operational purposes, St Dennis Junction where the long china-clay trains start and finish and the fictitious Southern line to Wadebridge. Polperran lies at right angles to Porthmellyn Road (parallel to Penzance in fact) and will be double-ended to save width. More on this another time.

 

Here is the frame itself. It's very simple. At the top is a horizontal member that is fixed to one of the Porthmellyn Road supporting legs (top right on the block plan). This will support the end of the two L-girders, one on each side, running towards the camera. The two vertical members are the legs for this end of the L-girders. They are fixed to a short piece of the original trial L-girder, which is turn is screwed to the concrete floor. Because the top horizontal member is only fixed in the centre, the two ends can be moved backwards and forwards a few millimetres due to the natural flexibility of the wood. I think that once the L-girders are up this won't be a problem but if it is I'll fit a separate strut - see below.

 

This shows the frame in context. When I took the photo I was standing in the aisle between Polperran and Penzance, facing Porthmellyn Road. The long china-clay train is standing on a temporary track that will become the Up Branch line. It's straight at the moment but the curve round to St Enodoc will start roughly where the loco is.

 

If I do need to add a temporary strut, it will go between the right-hand end of the frame and the leg at the back, forming a horizontal triangle.

 

I hope that all makes sense!

Edited July 17, 2023 by St Enodoc
images restored

[St Enodoc]

I did not have a good afternoon today.

 

I installed the two bracket signals - the Down Homes (2/17) and Down Inner Homes (3/7) - and the ground disc (10) that sits at the foot of the Inner Homes. Mechanically this was fine but electrically much less so.

 

After connecting 2/17, the subsidiary arm to the Loop worked fine but the main arm did not. I checked the power module to the best of my limited capability, electronics being a foreign language to me, and couldn't find anything obviously wrong like a dry joint or solder bridging the veroboard strips. I could only conclude that something had gone wrong with the LM317T regulator, so I left that for another day.

 

When I connected 3/7, both arms worked but very fast, which is usually a sign that too much current has been passed. This is a Bad Thing, as it overheats the memory wire and often causes it to melt break. This is indeed what has happened to 7 signal's actuator, so that will need rebuilding. I experienced this a couple of times on the old layout and had to replace the current regulator too.

 

Now, all this is rather hit-and-miss, frustrating and time-wasting. More importantly, memory wire is a finite resource, no longer available from my original supplier Jacques le Plat in Belgium, who retired a few years ago when his supplier stopped production. I (should) have enough to complete the layout but I can't afford to destroy it like this.

 

So, I think I will change course as far as signal power is concerned. While the current regulator should be an elegant and well-engineered solution, as I can't make it work reliably then I will abandon it. Instead, I will use what I had previously decided not to use, namely individual 1.5V dc alkaline batteries - as I have already done to the Trewoon Junction Up Main Distant. Here there is no danger of overcurrent, the only inconvenience begin having to fit a largish number of separate batteries and replace them when they go flat.

 

I don't actually need a separate battery for every arm. For example, of 3/7/10 signals only one can be Off at a time so a single battery will do. that cuts the number down to manageable proportions.

 

Regarding battery life, I found the Duracell (other brands are available) data sheets on the web and the life at a continuous discharge rate of 200 - 250mA ranges from about 4 hours for AAA cells to nearly 50 hours for D cells. I'll do a bit more comparison of the different sizes but my next order from the electronics shop is going to include a good number of battery holders.

 

The upside is that I now won't have to build any more current regulators, although I will use a modified form of the power module comprising just the relay, terminal block and (depending on which size I choose) the battery holder.

 

In summary, then, probably one step back and two forward.

[Nick C]

Is it worth looking at the rechargable batteries? I think they're 1.2v nominal rather than 1.5, but then you could just pop them out at the end of each operating session, stick them on charge, and pop them back in just before the next...

[Stubby47]

Will there be an entrance to Polperran FY from Pentowan and/or Porthmellyn ?

[St Enodoc]

26 minutes ago, Nick C said:

Is it worth looking at the rechargable batteries? I think they're 1.2v nominal rather than 1.5, but then you could just pop them out at the end of each operating session, stick them on charge, and pop them back in just before the next...

Thanks Nick. The challenge is the quantity. I haven't worked it out completely yet but it's likely that I'll need at least 40 batteries for the complete layout. Most of the chargers I've seen are for four cells at a time, so quite a task to charge 40. I need to balance the inconveninence of that against the cost of changing them periodically as they go flat (which they won't all do at the same time).

 

More on this later.

[St Enodoc]

30 minutes ago, Stubby47 said:

Will there be an entrance to Polperran FY from Pentowan and/or Porthmellyn ?

Stu, the entrance to Polperran is from Treloggan Junction, so yes, there is direct access from Pentowan (in the same way that there used to be direct access from Newquay to Shepherds, Perranporth, Chacewater and Truro).

 

There's no direct access from Porthmellyn Road, though. Apart from anything else, there will be about 45-50mm difference in height and it would need rather a sharp curve...

 

It would be nice to have a direct connection via the Penzance loops to run the 0815 SO Perranporth - Paddington, which started as ECS from Newquay, but there just isn't room. In any case, the loco was changed at Truro so for this one train we'll do a crane shunt with the three coaches.

Edited October 3, 2020 by St Enodoc

[St Enodoc]

30 minutes ago, St Enodoc said:

Thanks Nick. The challenge is the quantity. I haven't worked it out completely yet but it's likely that I'll need at least 40 batteries for the complete layout. Most of the chargers I've seen are for four cells at a time, so quite a task to charge 40. I need to balance the inconveninence of that against the cost of changing them periodically as they go flat (which they won't all do at the same time).

 

More on this later.

OK, so a quick check shows that a decent four-cell charger will cost about $25. That will recharge the cells in about 12 hours (give or take, depending on cell size). The Ni-Mh cells themselves have a much lower capacity than the alkaline equivalents and they cost about an order of magnitude more. Hence, the payback period is clearly far too long even to consider that option in more detail.

 

I'm leaning towards D cells, which cost about 3c per hour to run if bought in packs of 10 and should have a life of about 50 hours at 250mA.

[DougN]

No good about a few failures. I am not positive but I think Brunel models may have some old supplies. Might be worth a phone call to Mary. 

 

I found today to be such such a lovely day it ended up in the garden rather than doing some modelling. So if the weather all goes sideways tomorrow I may get some modelling done I guess! ,

[St Enodoc]

4 minutes ago, DougN said:

No good about a few failures. I am not positive but I think Brunel models may have some old supplies. Might be worth a phone call to Mary. 

 

I found today to be such such a lovely day it ended up in the garden rather than doing some modelling. So if the weather all goes sideways tomorrow I may get some modelling done I guess! ,

Thanks but no thanks Doug. Crude but effective is the way forward now. My next order from J****r will include a lot of battery holders. I'll certainly get the quantity discount...

 

The batteries themselves will probably come from that well-known DIY store where we used to be able to get a sausage sandwich. They offer good prices for bulk packs.

[Barry O]

I may have some memory wire.. I will, when I remember) send it to you... may not be exactly teh same stuff.. but it is worth a try!

 

how about one of these?

 

low voltage psu

 

Baz

[DougN]

Sorry I was meaning the memory wire! 

[St Enodoc]

Just now, Barry O said:

I may have some memory wire.. I will, when I remember) send it to you... may not be exactly teh same stuff.. but it is worth a try!

 

how about one of these?

 

low voltage psu

 

Baz

Thanks Baz, appreciate that.

 

That PSU is interesting. If it can really supply 1.5Vdc regulated with a capacity of 3A it would indeed be worth a look. I'd probably need one for each of the three signal boxes but that wouldn't break the bank.

 

I think I'd want to protect each memory wire actuator though, possibly with a fast-blow fuse. I'll sleep on it I think.

[St Enodoc]

25 minutes ago, DougN said:

Sorry I was meaning the memory wire! 

Ah, sorry. If I don't destroy much more I should be OK. Thanks for the tip anyway - I'll give them a call to see exactly what they have. Thanks.

Edited October 3, 2020 by St Enodoc

[Dr Gerbil-Fritters]

Regarding batteries, back in the days when I was a semi serious train photter I found that any brand of lithium ion batteries would power my digital camera for over a week whereas Duracell woudn't even last a day.  Most important as I was often out shooting in the wilds, miles and miles from any shops never mind ones that sold batteries.

 

 

No batteries for over 100 miles...

 

 

I can also state categorically that the batteries with the shortest lifespan are those bought from gas stations in the desert.  Ask me how I know.

Edited October 3, 2020 by Dr Gerbil-Fritters
photos

[acg5324]

I do like a double stack.....had a cab ride over Sherman Hill on the leading SD70M, UP double stack....absolutely fantastic trip.

[Clive Mortimore]

3 hours ago, Dr Gerbil-Fritters said:

Regarding batteries, back in the days when I was a semi serious train photter I found that any brand of lithium ion batteries would power my digital camera for over a week whereas Duracell woudn't even last a day.  Most important as I was often out shooting in the wilds, miles and miles from any shops never mind ones that sold batteries.

 

 

No batteries for over 100 miles...

 

 

I can also state categorically that the batteries with the shortest lifespan are those bought from gas stations in the desert.  Ask me how I know.

Hi Doc

 

So you have been to the part of Lincolnshire I now inhabit.

[St Enodoc]

2 hours ago, acg5324 said:

I do like a double stack.....had a cab ride over Sherman Hill on the leading SD70M, UP double stack....absolutely fantastic trip.

Andy, have you seen this topic?

 

 

[St Enodoc]

Bob Rogers, the doyen of Sydney radio presenters, retired last night, after presenting his final "Reminiscing" programme, at the age of 93 after 78 years in the business. While listening to his final show, which was as good as any I've heard, I repaired the broken actuator for 7 signal then researched the voltage regulator that Baz mentioned earlier. 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?

[St Enodoc]

9 hours ago, Dr Gerbil-Fritters said:

Regarding batteries, back in the days when I was a semi serious train photter I found that any brand of lithium ion batteries would power my digital camera for over a week whereas Duracell woudn't even last a day.

Thanks Doc. Just checked some prices. AA size Duracells are about 50c each in bulk. "Ordinary" AA lithium cells are about $4 and so-called "Long Life" AA lithium cells are about $8 each. I'll probably go with Duracell D cells ($1.67 each in bulk) if I don't follow the voltage regulator path.

[Oldddudders]

We are told that Duracells are very widely faked. Tough to know whether the bulk offers are the real thing. 

[St Enodoc]

17 minutes ago, Oldddudders said:

We are told that Duracells are very widely faked. Tough to know whether the bulk offers are the real thing. 

Thanks Ian. When I say "bulk" I mean the packs sold by our local DIY superstore. In that context a bulk pack of AAs or AAAs is 48, while a bulk pack of Cs or Ds is 10. I've had no problems with these in the past. I don't mean the packs of 100 or so that you can buy through, for example, eBay or Amazon.

[St Enodoc]

Following yesterday's debacle with the signal power, I didn't do much in the railway room today other than fitting 3/7 signal and 10 disc back on the baseboard. I tried Black Tack instead of Blu Tac for the first time and it certainly seems to have a stronger grip.

 

Once I'd done that I came back in and finished the nine actuators I started the other day, so I can get on with the next batch of three ground discs - 11, 16 and 21 - next. I'll describe the build as I go along.

[acg5324]

10 hours ago, St Enodoc said:

Andy, have you seen this topic?

 

 

No, will do now.

[St Enodoc]

To build the ground discs you need parts from three sources plus left-over bits of 0.5mm nickel-silver or brass wire and some styrene sheet scraps.

 

The bases and mounting tubes come from the Ratio signal remote control kit, pack 250. They're the only parts you need - the springs, cord, eyelets and lever parts are surplus for this job.

 

The disc signals themselves are included in the Ratio single-post signal kits, packs 460/461/462. You get one disc per kit. If by any chance you need more discs than signal posts you can get them separately in pack 465.

 

Finally, although the Ratio kits include plastic moulded discs I use Scale Links discs, as for all my signal arms.

 

Usual disclaimer applies in respect of these suppliers of course.

 

I start with the bases and the tubes. The underside include three sets of ribs for locating the tube (left). These might need a bit of trimming to fit. The top of the base includes a small square moulding to locate a signal post (centre). We don't need this, so file it flat (right).

 

Clean up the tube and glue it to the underside of the base. Clamp it if you can, then leave it overnight to harden.

 

While you're waiting, it's a good time to prime the front and back of the disc etching.

Edited July 17, 2023 by St Enodoc
images restored