Trelothen - a Cornish fishing harbour

[Stubby47]

Have spent an hour this evening tracing a fault that wasn't there last night.

 

Turns out the one Frog wire I connected to the Cobalt is from a duff point, so it seems leaving the wire off won't adversely affect the layout.

Not convinced about this  so the point might be replaced. It's the re-used one with the grey sleepers.

[Stubby47]

All 6 point motors are now installed and working in pairs to change the 3 cross overs.

Next is to complete the frog switching wiring, then the 15-pin D socket on the layout, then tidy all the wiring with cable ties, etc 

Next after that is the cable, then I can start to test with locos.

There are 3 more sidings to add, with 1 electro and 2 magnet uncouplers, then the Yard is complete. 

 

After that I'll need to dismantle T-Cats as I'll need the space for board #2. This will allow me to test gradients and thus determine the height of the Station area.

[Stubby47]

So, layout wiring done ( apart from fitting one electro magnet.

 

Cable/s now done.

 

Plug in the power source and........

 

 

Nothing.

 

Still chasing as to why.

[St Enodoc]

13 minutes ago, Stubby47 said:

So, layout wiring done ( apart from fitting one electro magnet.

 

Cable/s now done.

 

Plug in the power source and........

 

 

Nothing.

 

Still chasing as to why.

Did you put a shilling in the meter?

[Stubby47]

2 minutes ago, St Enodoc said:

Did you put a shilling in the meter?

Yep, power is on.

 

I think I've c*cked up the 'cable'.

 

I've also managed to get the two cable parts different lengths, so I might just strip the two plugs off and re-wire.

[Stubby47]

Initial testing is that there is power to the inside of the D-connector (inside the panel), but I'm not sure the power is being supplied to the outside of the D-connector (i.e. the connector itself is u/s).

 

Currently stuck in an all-day (actually 3 days) training for planning software...

 

[Donw]

5 hours ago, Stubby47 said:

Initial testing is that there is power to the inside of the D-connector (inside the panel), but I'm not sure the power is being supplied to the outside of the D-connector (i.e. the connector itself is u/s).

 

Currently stuck in an all-day (actually 3 days) training for planning software...

 

 

Never did think much of those D connectors. Mind you it is quite common to find issues when wiring up a layout. It is not uncommon to find professionals finding issues. While a cable jointer one of my colleagues was much quicker and neater at jointing than myself  but not keen on testing.  When he got the telephone lines of some houses crossed and failed to check they were ok before packing up for the day, he was rather red faced in the morning to find out that one of the families daughter lived in America and giving birth to her first born and had spent half the night answering and making calls on their neighbours phone. Fortunately they all took it very well. A good object lesson in the value of testing.

 

Don

[Stubby47]

It turns out the cables are not really up to the job. They are 4-pair, single-core, so quite fragile and several of the soldered connections have failed.

 

I need to source something better....

[ian]

Never use single core on a cable that will be flexed - they break. Always use multi-core for that sort of a job.

 

Benn there, got the tee-shirt.

[Stubby47]

Yeah, I realise that now, they were just handy cables I had to hand.

 

Looking at buying a set of coloured cables in a box, but not sure what size (12AWG - 30AWG) is big enough, but not too big.

 

EG: https://www.amazon.co.uk/TUOFENG-Wire-Solid-Different-Colored-spools/dp/B07G744V5Z/ref=asc_df_B085TPC8GZ/?tag=&linkCode=df0&hvadid=430802235498&hvpos=&hvnetw=g&hvrand=5525144380879387682&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006597&hvtargid=pla-907507812410&ref=&adgrpid=103132776954&th=1

 

Edited August 24, 2021 by Stubby47

[ian]

1 hour ago, Stubby47 said:

Yeah, I realise that now, they were just handy cables I had to hand.

 

Looking at buying a set of coloured cables in a box, but not sure what size (12AWG - 30AWG) is big enough, but not too big.

 

EG: https://www.amazon.co.uk/TUOFENG-Wire-Solid-Different-Colored-spools/dp/B07G744V5Z/ref=asc_df_B085TPC8GZ/?tag=&linkCode=df0&hvadid=430802235498&hvpos=&hvnetw=g&hvrand=5525144380879387682&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006597&hvtargid=pla-907507812410&ref=&adgrpid=103132776954&th=1

 

Based on Farnell's data:

 

18 awg == 16 x 0.255mm

22 awg == 7 x 0.255mm

 

So 22 awg should be fine for your light current draw and short cable runs.

Edited August 24, 2021 by ian

[St Enodoc]

1 hour ago, Stubby47 said:

Yeah, I realise that now, they were just handy cables I had to hand.

 

Looking at buying a set of coloured cables in a box, but not sure what size (12AWG - 30AWG) is big enough, but not too big.

 

EG: https://www.amazon.co.uk/TUOFENG-Wire-Solid-Different-Colored-spools/dp/B07G744V5Z/ref=asc_df_B085TPC8GZ/?tag=&linkCode=df0&hvadid=430802235498&hvpos=&hvnetw=g&hvrand=5525144380879387682&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006597&hvtargid=pla-907507812410&ref=&adgrpid=103132776954&th=1

 

 

20 minutes ago, ian said:

Based on Farnell's data:

 

18 awg == 16 x 0.255mm

22 awg == 7 x 0.255mm

 

So 22 awg should be fine for your light current draw and short cable runs.

How about some computer-style ribbon cable? I think that's multi-strand.

[Stubby47]

Just now, St Enodoc said:

 

How about some computer-style ribbon cable? I think that's multi-strand.

 

I do have some of that, but not long enough (I'm looking at a couple of meters of length, more if possible).

[Stubby47]

Have gone for this:

 

https://www.amazon.co.uk/gp/product/B07G712DY4/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

[St Enodoc]

2 minutes ago, Stubby47 said:

Have gone for this:

 

https://www.amazon.co.uk/gp/product/B07G712DY4/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

30 awg might be a bit thin...

[Stubby47]

4 minutes ago, St Enodoc said:

30 awg might be a bit thin...

 

I need to get 15 wires into a D connector cover, so was a bit concerned anything larger would be too much.  It's rated at 60v, which should be enough.  It's a learning curve

[ian]

It says it is super low impedance so with a bit of luck you'll be OK.

 

It does sound more like DCC decoder wire than layout wire though.

Edited August 24, 2021 by ian

[Andrew P]

5 hours ago, ian said:

Never use single core on a cable that will be flexed - they break. Always use multi-core for that sort of a job.

 

Benn there, got the tee-shirt.

 

5 hours ago, Stubby47 said:

Yeah, I realise that now, they were just handy cables I had to hand.

 

Looking at buying a set of coloured cables in a box, but not sure what size (12AWG - 30AWG) is big enough, but not too big.

 

EG: https://www.amazon.co.uk/TUOFENG-Wire-Solid-Different-Colored-spools/dp/B07G744V5Z/ref=asc_df_B085TPC8GZ/?tag=&linkCode=df0&hvadid=430802235498&hvpos=&hvnetw=g&hvrand=5525144380879387682&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006597&hvtargid=pla-907507812410&ref=&adgrpid=103132776954&th=1

 

I did on Glen Roy to start with, got to a show, set up and 3 Points not working, the solid common wire had broken en route in the Car.

After the Show, all the wiring using GPO Phone cabling was replaced.

Edited August 24, 2021 by Andrew P

[steve45]

9 hours ago, Stubby47 said:

 

I need to get 15 wires into a D connector cover, so was a bit concerned anything larger would be too much.  It's rated at 60v, which should be enough.  It's a learning curve

Surely its Amps not Volts that is important measure?

[Stubby47]

Well, the wire has arrived and as suggested, it's quite small.

 

However, after having a tinker last evening, I have stripped the main socket on the baseboard and will add wires one pair at a time to that and the link cable.

 

  

[Donw]

As a Telephone engineer I worked a lot with single core wire. I would regularly joint 100 pair cables without breaking any. However that is due too how they were jointed.

The danger point with single core is stripping the wire using excessive pressure the cable strippers or cutters can score or nick the wire creating a stress point. When soldered to a Tag the end of the insulation is typically close to the join and any flexing can break the wire at that point. When jointing external cables we twisted the wires together but the first few twists were insulated so any strain was taken by wire and insulation. The termination on tags at say the exchange would be with the tag block firmly fixed to a frame and the cable also anchored to the frame where is was sheathed so apart from making the joint there was never any movement .

Note Internal cable had tougher insulation than external cables. The small sizes of external cables were usually filled with petroleum jelly to keep water out not much use for model railway layouts. 

Generally I would recomment multi stranded wire apart from a DCC bus wire were if you have some of the old RED/Black mains cable with the sheath removed  1.5mm2 or 2.5mm2  wire is pretty tough but I would still only use it for wire fixed to the baseboard. Any flexible cable multi strand wire is essential.

Before anyone says never use mains wire. I say never allow mains voltage onto the basboard use modern reliable makes of PSU and only the low voltage output gets onto the baseboard that includes lighting. If you are daft enough to connect mains voltage without checking what you are connecting to chances are you will fry yourself fiddling with the house mains.

 

Don

 

 

[Stubby47]

I've re-wiring and re-re-wiring the layout 15-pin socket and the cables over the just week, trying to get the point motors to work.

 

They all work correctly as a matched pair and a 9vdc feed.

The switches are correctly wired in the panel to the correct pins.

 

But, when I power up the layout, 2 pairs of motors move at the same time, but only when one of two switches is used.

 

Thi, and other peculiarities, has had me stumped.

 

But, a lightbulb moment has occurred. 

 

It's all to do with the panel switches.

 

I've used simple DPDT ones, the middle pins feeding the motor and the outer pins connected to the 12v dc input on one side and cross-wires to the other side to reverse the polarity. 

 

And so the fault is due to the power feed shorting as it feeds through the motors and back to the switches.

 

I need to swap the input & output on the switches.

[Stubby47]

But that hasn't worked either.

 

So, the next plan is to turn two of the motors around so the motors work in the same direction, although the physical action is opposite.

[Stubby47]

And that's not worked either.

 

The more I think about this, the more I realise that ON-OFF-ON DPDT switches, as recommended in the Cobalt instructions, just won't work.

 

As soon as one switch is used, as the motors are stalled, they will still pass power through. So a 2nd switch immedately causes a short.

 

What a waste of time.

 

I can use (ON)-OFF-(ON) switches, but I lose the physical indication of the point settings.

 

Somewhat p'd off.

[Andrew P]

I've followed what you've done, and I can't see what is wrong with what you've done, basically it should work!