Mid-Cornwall Lines - 1950s Western Region in 00

[St Enodoc]

I had a busy and productive day today.

 

First I made up the four power modules for the signals I installed last week.

 

 

These photos show both sides of the module. Looking at the connector block in the first photo, the left-hand pair of terminals is for the 9V dc feed and return from the signal box. This energises the relay coil at the back on the left. There is a freewheel diode across the coil. The relay is hot-glued to the base.

 

The middle pair of connectors is for the 12V dc signal power feed input to the LM317T circuit. This is fed through the relay NO contacts.

 

The right-hand pair of connectors is the regulated 220mA output to the signal memory wire actuator.

 

In the second photo you can see the LM317T circuit itself. It's built on a strip of veroboard and a screw through the hole in the LM317T attaches the whole thing via the heatsink to the base. At the top is the big 5.6 ohm resistor and just poking out between the resistor and the LM317T is the capacitor. The base is a piece of 6mm ply recycled from the old layout, where it added extra thickness to the baseboard end where some screws needed to go.

 

On the layout, I started by completing the wiring from the lifting flap back to the signal box. The wiring is now in place for all three signals at this location but I've only mounted the power module for signal 49 so far. The modules for signals 2 and 17 will go above this one and the common wires will be daisy-chained. The cream and violet output wires go to a socket fixed to the baseboard, which the signal's jack plug fits into so that the signal can be removed easily if necessary.

 

Finally, the result - 49 signal in the Off position. To achieve this:

 

- the Paddington "From Porthmellyn Road" Line Clear Release switch is switched to Clear

- this energises the Line Clear circuit that lights up the LED push-button for 49 signal at Porthmellyn Road signal box

- pressing the button energises the Eemeck that releases the lock on lever 49

- pulling lever 49 operates the signal.

 

Very satisfying!

 

I hope to get the three other signals working over the weekend, then I can build some more.

Edited July 17, 2023 by St Enodoc
images restored

[Bogie]

Where's the "S**t I think that's good but I wouldn't know" button when you need it?

[5BarVT]

1 hour ago, Stubby47 said:

 

Update.

 

As great-grandmother was born in 1873, the Sandwich Islands were not part of the US of A at that time, so I'm part Hawaiian, but not part American.

 

Phew!

:-)

Paul.

[St Enodoc]

Ooh! I see that we now have a "Groan" button!

 

I will make every effort to create reasons for you to use it.

[brushman47544]

5 hours ago, Stubby47 said:

 

Update.

 

As great-grandmother was born in 1873, the Sandwich Islands were not part of the US of A at that time, so I'm part Hawaiian, but not part American.

 

 

That at least will mean you are not liable for years of US back taxes.

[bgman]

5 hours ago, St Enodoc said:

First I made up the four power modules

 

I haven't a Scooby Doo what you've done matey but the photograph says it all, nice work !

 

( I took the easy way out and bought a servo controller board from Dave at Megapoints !!!  Nice bounces )

 

G

[Stubby47]

7 hours ago, Stubby47 said:

 

Update.

 

As great-grandmother was born in 1873, the Sandwich Islands were not part of the US of A at that time, so I'm part Hawaiian, but not part American.

 

 

Further update.

 

According to family history, apparently great-great grandfather & family moved out to Hawaii to help develop the new railways being built for the Sugar plantations.  As he was previously a brewer, we are not sure how/why that would be the case, but another theory is the eldest son was a pattern maker and it might have been his career path that was being followed.

[St Enodoc]

8 hours ago, bgman said:

 

I haven't a Scooby Doo what you've done matey but the photograph says it all, nice work !

 

( I took the easy way out and bought a servo controller board from Dave at Megapoints !!!  Nice bounces )

 

G

Thanks Grahame.

 

If I were starting again from scratch, I think I'd use servos too. If, by any chance, I run out of memory wire, then that's the way I'll go to finish off. Apart from actually moving the signal arms, everything else would probably stay the same.

 

I'm not too worried about the bounces. I think they can be overdone on models. The smooth action was what I wanted, both for the visual effect and also so that the Ratio signals weren't ripped to shreds by the operating mechanism (been there...).

[aardvark]

21 hours ago, Stubby47 said:

As great-grandmother was born in 1873, the Sandwich Islands were not part of the US of A at that time, so I'm part Hawaiian, but not part American.

 

Thanks to all that RMWeb is, I have discovered that your good friend and mine, Capt. James Cook, was a serial sandwicher.  He named an uninhabited atoll in the Cook Islands "Sandwich Island" in 1773, then an island in Vanuatu in 1774, then a group of island near South Georgia in 1775, then Hawaii in 1778.

 

My wife says that it's unclear whether he had contracted a tropical disease, or whether he suffered from the results of an unbalanced shipboard diet, as the writing in his journals got more and more erratic as the years progressed.

 

It must have been of great relief to him that, should they have been shipwrecked at any of these, his crew would have been able to eat the sandwiches there (sand which is there).

Edited September 12, 2020 by aardvark
added the South Sandwich lslands (1775)

[sandwich station]

48 minutes ago, aardvark said:

 

Thanks to all that RMWeb is, I have discovered that your good friend and mine, Capt. James Cook, was a serial sandwicher.  He named an uninhabited atoll in the Cook Islands "Sandwich Island" in 1773, then an island in Vanuatu in 1774, then Hawaii in 1778.

 

 

Named after the 4th Earl of where I come from.  

[aardvark]

11 minutes ago, sandwich station said:

 

Named after the 4th Earl of where I come from.  

 

The 4th Earl of Melbourne?

[sandwich station]

5 minutes ago, aardvark said:

 

The 4th Earl of Melbourne?

 

Originally   

[St Enodoc]

An equally busy but slightly less productive afternoon today. 30 signal (the exit from the Down Goods Loop) was easy enough but at the other (Down) end of the station things went more slowly. It's a lot more congested under the baseboards here, with six signals (eventually) in a relatively small area where the baseboards are quite narrow. I therefore spent a bit of time working out where to put the power modules. I then installed the modules for 4 and 53 signals but only got 53 wired up and working before I ran out of time. I should get 4 signal working tomorrow.

 

As a result of all this, I might make up and install the rest of the power modules for this end of the station before I build the signals themselves. I think getting at everything might be easier that way round.

[St Enodoc]

I finished 4 signal this afternoon. All went well and the signal works smoothly, so I spent a little while looking at how I might modify the wiring to the Trewoon Junction Up Main Distant, following @5BarVT Paul's pestering last week.

 

Short answer: unfortunately, I won't.

 

Long answer: I had forgotten that the Cobalt point motors only have one true set of changeover contacts. These are available for auxiliary circuits if you use the motor's internal switching to power the frog direct from the DCC track bus but I can't do this because I use a separate accessory bus. Consequently, unless I fit another switch (either a microswitch - unlikely - or a separate accessory decoder - possible) to the three points concerned, I won't be able to interlock the signal with the Tregissey routes after all. I will think about whether to use a couple of the spare AD-S2fx decoders, which became redundant after the change from H&M motors to Cobalts, but for the time being at least the signal will come off every time the Line Clear Release is sent from Paddington to Porthmellyn Road.

 

Either way, I still think it will be fun to see the signal operate "untouched by human hand".

[aardvark]

You power turnout frogs from your accessory bus? Or just the associated control circuitry?

[St Enodoc]

2 minutes ago, aardvark said:

You power turnout frogs from your accessory bus? Or just the associated control circuitry?

The motors are activated from the accessory bus using the built-in decoders on the Cobalt iP Digitals. That means I have to use the other "real" changeover contacts (terminals 4/5/6) for the frogs.

 

If I powered the motors from the track bus, I could use the separate "Frog" output on the motor (terminal 3), leaving the "real" changeover contacts spare.

 

https://www.dccconcepts.com/manual/owners-manual-cobalt-ip-digital-point-motors/

 

 

[5BarVT]

4 hours ago, St Enodoc said:

following @5BarVT Paul's pestering last week.

Can’t win them all, thwarted by Cobalts: should’ve used Tortoises!

If we don’t tell anyone, they won’t know. 

:-)

How far away is Trewoon Junction?  Could it be an intermediate block distant?  (Although IB on approach is more Southern practice, all the WR IB’s I know were in the block section beyond.)

Paul.

[St Enodoc]

On 13/09/2020 at 21:46, 5BarVT said:

Can’t win them all, thwarted by Cobalts: should’ve used Tortoises!

If we don’t tell anyone, they won’t know. 

:-)

How far away is Trewoon Junction?  Could it be an intermediate block distant?  (Although IB on approach is more Southern practice, all the WR IB’s I know were in the block section beyond.)

Paul.

Don't worry Paul. If the motors were Cobalt iP Analogue, as I use with the lever frame, all would be well as they definitely have two proper changeover switches. They would, however, need a separate decoder (as do Tortoises, so no benefit there in fact).

 

The spare decoder option is still a possibility but it's slipped further down the queue than the straight changeover switch idea.

 

The distance to Trewoon Junction isn't far enough I'm afraid, Paul. On the real railway the distance from Trenance Junction SB to Burngullow SB was 2m 10c. The fictitious Trewoon Junction is roughly halfway between them (replacing Trenance Sidings SB), where the link from the re-gauged and extended Pentewan Railway meets the main line. See the location map:

 

Edited July 17, 2023 by St Enodoc
images restored

[Chamby]

4 hours ago, St Enodoc said:

The motors are activated from the accessory bus using the built-in decoders on the Cobalt iP Digitals. That means I have to use the other "real" changeover contacts (terminals 4/5/6) for the frogs.

 

If I powered the motors from the track bus, I could use the separate "Frog" output on the motor (terminal 3), leaving the "real" changeover contacts spare.

 

https://www.dccconcepts.com/manual/owners-manual-cobalt-ip-digital-point-motors/

 

 

 

I also use digital cobalts activated from a separate accessory bus and from experience can suggest that you have two possible workarounds to get around the lack of a spare changeover switch on the point motors.

 

Firstly you can use a microswitch... fixed under the baseboard and activated by the steel wire of the motor.  The pressure required to trigger the switch is minimal and doesn’t affect the motors performance.

 

Secondly, and a far more elegant solution, use a separate digitally activated switch set to the same accessory number as the point, so it works in unison.  This is an infinitely scaleable option and can be installed anywhere you like on the layout, simply wire it into the bus.

[5BarVT]

3 hours ago, St Enodoc said:

See the location map:

Ah!  My fictional geography has let me down.

Since PM Rd is the Par layout I had it in my head that it was the Par location.  (But having been copying your timetable spreadsheet for my layout I had been puzzled by the direction that locos from St Blazey arrived.)

Now I’m sorted.

Paul.

[St Enodoc]

8 hours ago, Chamby said:

 

I also use digital cobalts activated from a separate accessory bus and from experience can suggest that you have two possible workarounds to get around the lack of a spare changeover switch on the point motors.

 

Firstly you can use a microswitch... fixed under the baseboard and activated by the steel wire of the motor.  The pressure required to trigger the switch is minimal and doesn’t affect the motors performance.

 

Secondly, and a far more elegant solution, use a separate digitally activated switch set to the same accessory number as the point, so it works in unison.  This is an infinitely scaleable option and can be installed anywhere you like on the layout, simply wire it into the bus.

We're on the same page, Phil.

 

I don't think this is important enough to try to find space for and squeeze in three microswitches. The underside of the baseboard is very congested here with all the fans converging and the associated point motors, leads, buses, feeders and droppers.

 

The extra decoders are a definite possibility. If I can work out how to do it with what I already have, namely the redundant DCC Concepts solenoids decoders, then I will. Suggestions welcome! It's not important enough to go out and buy new units, maybe Switch-Its or Snap-Its, though.

[St Enodoc]

5 hours ago, 5BarVT said:

Ah!  My fictional geography has let me down.

Since PM Rd is the Par layout I had it in my head that it was the Par location.  (But having been copying your timetable spreadsheet for my layout I had been puzzled by the direction that locos from St Blazey arrived.)

Now I’m sorted.

Paul.

Yes, although the track layout is based on Par I moved the location for various reasons that are outlined on page 2:

 

I probably should have "closed" the actual line between Bugle and St Dennis Junction. If I ever have reason to update the location map I might do that.

Edited September 13, 2020 by St Enodoc

[Barry O]

Wish I could move my location to somewhere warmer!!

Baz

[5BarVT]

19 minutes ago, Barry O said:

Wish I could move my location to somewhere warmer!!

Baz

I have!

And it’s not as wet too.

Paul.

[St Enodoc]

Tonight I made up twelve more power module bases with relays and terminal blocks, using the remaining plywood rectangles recovered from the old layout, then completed five of these with pre-built current regulators, also recovered from the old layout. I'll mount four of these five at Porthmellyn Road Down end and the remaining one between the viaduct and lifting flap, pending construction of their associated signals.

 

From now on I'll go back to building things in smaller batches. I like batches of three but for the next round of signals I think it will be pairs of two-armed signals, that is junction signals or two arms on a single post. For Porthmellyn Road I need another 27 motorised arms/discs/banners, although four of these won't come into use until the branch is built.