5BarVT

2 minutes ago, BoD said:

That stamp is a swine to wash off though.  
Actually it might save me the entrance fee next year.

Ah.  Don’t you know it wears off after precisely 362 days.

:-)

Paul.

On 23/02/2024 at 09:57, Emma H said:

All tickets booked for tomorrow. Catching the 05:59 Crewe - Glasgow service so the alarm is set for 04:30 😴😴😴

Good to see you today. Now you know who it is when I’m spouting about signalling. 
And who to slag off when I get it wrong!!!

Paul. 

4 minutes ago, Andy Keane said:

Jenkin's photo shows just how complicated even the points at a minor place like Nancegollan could be - you are not going to be able to buy that combination of frogs RTR anytime soon!

You almost can!  It’s just a tandem turnout (asymmetric three way) with the following turnouts hard on the crossing nose.  Might manage something quite close with some point trimming.

Paul.

P.S. Meant to say that ITG’s idea of drawing up a wiring plan from your layout (hopefully knowing how your DCC bus and droppers are routed) would be a good feasibility study.  That would give you an idea of how much effort and cost will be involved.

If you discover that JMRI does not need continuous train detection, and you go with diode drop detection, Iain’s comment about back to back diodes for undetected areas means either a pair of diodes for each junction area, or, a second bus around the junction areas.
 

Paul.

Still using current sensing, there are some designs that use a transformer design rather than diode drop.  Although mine are all on the same polarity, they don’t have to be as there is no electrical connection between the rail and the sensing circuit.  Will still require fiddling around under the board to separate wires and route the right ones through the toroid.  Thats where it’s easier if the boards separate so they can be upended for working on and ‘too late now’ if they don’t.

I use Rr-Cirkits Watchman available from Coastal DCC, supplemented by MERG DTC2 where a multiple of 8 is not cost effective.

Train detection in turnout areas is an interesting topic (!).  For the commercial systems (iTrain and Traincontroller) you don’t need it to make the programme work, for JMRI you would need to check.  (I think I have seen a JMRI discussion that hinted that train detection sections need to be abutting for its logic to work properly.). When comparing, also beware terminology differences - in TC and iTrain a Block is the track between points where the train will stop and may have one or more train detection Sections. In JMRI, Sections are the track between the points which may contain one or more Blocks!

I’ll be back with more generic thoughts later.

Paul.

1 minute ago, RobinofLoxley said:

Visit the webpages of Brian Lambert, very well known on here, and read the DCC sections.

I was about to say exactly that!

web site is https://www.brian-lambert.co.uk/

Paul.

On 22/01/2024 at 19:57, GloryDays said:

the coupling was far too low.

I’ve had droopy Heljan couplings.  A sliver of (say) 10thou plasticard in the NEM mount can help it stay up.  Possibly the Hornby coupling is thicket and achieving the same result.

Paul.

9 minutes ago, BWsTrains said:

Meanwhile, assuming it is really meant to be a "spot the bus" comp, I claim my 5 quid, having spotted 8 buses on bridges in pic no 2.

No, because there are 9 on bridges.

Paul.

2 hours ago, big jim said:

Battle scarred 92020

Depots is dangerous places!

Paul.

5 minutes ago, Jeremy Cumberland said:

 

Well, well. I now suspect what you have is the bottom switch, whereas what I and I am sure everyone else had assumed was that you had the middle switch.

 

The bottom switch won't work. On the face of it, you need to connect the two NCs together and the two NOs together, but you'll then get a short in the centre "off" position.

 

You need the middle switch.

 

Almost!!

You can’t put the power on the C pins because of the short you describe.

But, if you put the power on the NO and NC pins (linked NO to NO, NC to NC) and the motor on the C pins then you don’t get the short.

Hopefully the switch will test out as per Jeremy’s table and then you can try the alternative wiring.

Paul.

27 minutes ago, sulzer71 said:

Thanks for all the input guys , I have been mailing the seller and trying to explain what I need the switch to do but as can be expected they don't really understand!

 

I have got one switch to do a normal function (turn on power to something) , for this I have wired a negative feed to the bottom left common post , then one from the same side of the NO to negative side of the device that needs switching on , my positive feed goes to the right pin on the NO and then to the device , I've found that you can do this on either side of the switch 

 

Turn the switch right and device switches on , turn it centre it's off , turn it left and nothing happens

 

When you do the same but on the NC pins it turns device on when switched to the left but also stays on when in the centre position , turn it right and the device goes off

 

Am I missing something?

 

Cheers

That’s a much better way of testing!

Using both sides of the switch is making it more difficult to work out what’s happening because you don’t know whether it is the positive that is being switched, or the negative, or both.

A better approach (using the kit you have) would be to wire the +ve direct to the device and use each side of the switch in turn as follows:-

-ve to common, device -ve to NO, record L, C, R.  Repeat with device to NC and record.  Repeat both for other side of switch.

Those results will show how each side is connected.  It assumes there are no connections between the two sides, but we can deal with that later if necessary.

Paul.

9 hours ago, Clive Mortimore said:

Do you want the long story or the short one.

 

Before the Bachy Type 4 was produced I embarked on a "let's do something with these Tri-ang Co-Cos" gig. I had knocked up 3 Type 4 looking bodies which were to go on some lengthened (donated) Mainline Peak Chassis. The Peak chassis turned out not to be good runners, so things got put on the back burner while I had a second think. I did try fitting a Lima H0 class 33 power unit in a Peak bogie and that sort of worked.

Years passed and I was mooching around a stand selling all sorts of spare bits and bobs and spotted some class 40 bogies and motors. I will buy them I said to myself and went to pay for them and gent selling the bits pointed out the drive shafts so they were put in my bag as well. 

A couple more years passed and I found myself being daft and volunteering to man the DEMU stand at Doncaster. Panic set in as making a K4 2-6-0 did not seem the correct thing for the acting chair of DEMU to be making on a DEMU stand. How about having a go at doing a class 40 chassis?

 

An old photo of D399 perched on a lenthened Mainline Peak chassis

With a little bit of filing the Tri-ang English Electric windscreens can start to look.

 

This was an earlier attempt to do a stretched Tri-ang Co-Co. Lima chassis.

 

Before using bits left over from Baby Deltic cut and shuts, I made this from some plastic card.

Mainline Peak chassis.

Are (were) you feeling alright?  There’s some paint on them and they look almost complete.

Concerned of the GWR.

29 minutes ago, sulzer71 said:

but for some reason when crocodile clips are attached it will spark/arc as if there's a short

I’m suspicious about the wording of the description.  They are called DPDT, but the 2 position is SPDT not DPDT.

Now there is a version of DPDT switch that can be made into a three position ON-ON-ON SPDT.  If you put the standard ‘cross’ on that type of DPDT you will get a short in the centre position.  Given that they call the 2P switch DPDT when it isn’t, I wouldn’t be surprised if the 3P isn’t a ON-OFF-ON DPDT either.

I’m not keen on testing contact positions by looking for a short - there’s a good chance of damaging the contact so that it won’t work anyway once you know how the contacts are arranged.

Paul.

5 minutes ago, sulzer71 said:

It does have connections for the LED but the switch itself is the DPDT latching version

So it has 8 connectors?

Paul.

3 hours ago, sulzer71 said:

Morning All

 

As you guys are clearly more clued up than I am then I would like to know if it's possible to wire the switch pictured here to do what the standard switch people use for tortoises (also pictured)

 

I've bought some from AliExpress and cannot get them to reverse the polarity no matter what I try

 

They are 3 position switches with a centre off I believe

 

Yes and no (I think)!

The diagram for your switches looks like a single pole switch with connectors for an LED - would need to see from the back to be sure.

Assuming they are only single pole then:-

Can you wire it like the “standard switch”? No.

Can you use it to drive a tortoise? Yes.  You just need (a) differently configured power supply/supplies.

In the tortoise wiring instructions (http://www.circuitron.com/index_files/ins/800-6000ins.pdf  ) the “standard” switch is Diagram 1.  Your switches need Diagram 2 with 2 supplies or Diagram 3 with an AC supply and diodes.

Hth

Paul.

10 hours ago, Andy Keane said:

Might it be worth considering 2mm A grade ply for strength?

Next step is a 6” wide full height module (1 of three required for the full frame). I’m expecting that to be sufficiently rigid, but ply is an option if it isn’t.  There’s also the option of putting extra cross pieces for strength, but I need to leave openings for getting bits in and out.

Paul.

14 minutes ago, St Enodoc said:

How big is that overall, Paul?

2 1/2” wide (63.5mm).

From memory, the height is 151mm and when full size the height will be 271mm.  Width for my 35 lever frame will be 18” 457.2mm plus 10mm each end for the prototype finish.

Paul.

6 hours ago, Barry O said:

 "different rail mounted vehicles

Turbo***.

:-)

It is Sunday after all!

Paul.

And only a phone call away for Tuesday and Thursday.

Paul.

3 minutes ago, Andy Keane said:

nice work with the CAD and laser!

Thanks.

It suits my skills and desired outcomes.

Paul.

RUNNING SESSION

Must have been an MLV shortage last running session.  (Aye right!)

Paul.

Meanwhile, I have been busy “modelling”.

I’ve had to learn a new CAD programme suggested by RMWeb users - the open source LibreCAD.  It’s been a learning curve but I’m getting there.  Now I’m getting to grips with how it works, it is much better for what I want to do than my previous arrangements, and it interfaces to the laser cutter software in a much more efficient manner so I’m pleased I had to put in the effort.

Thus, today I cut and assembled this test piece.

A couple of errors discovered that can be sorted before I go to full size. The top (indication panel and lever section) is proper size, the bottom is very much reduced so as not to waste mdf.  The bottom will be increased to scale size to take the interface electronics and the width increased from 5 to 12 lever sections for the real one.  Cladding for the front and ends also needs to be designed.

Still lots of fun to be had.

Paul.

Sorry to keep you waiting for so long.  The jigsaw was finished in about a day and a half.

The most difficult bit was the edges - hence the ruler to line them all up when testing which one fitted best.  A sign of a quality producer, each edge has a different amount of white border so it was possible to separate into,four piles of edges.

Very suitable for my tastes, and Keith was closest.

Paul.

1 minute ago, Fishplate said:

rotring pens.

I could bring those too.  All dried out, not used for 30+ years.  Hand too shaky even if they did work.

Paul.

1 hour ago, Bucoops said:

Showing your age now, calling them Radiospares!

Showing my age as I read Radiospares without noticing.

Was late 70s when the change happened.

Paul.