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Charlton Bridge - 4mm BR(S) - Building Bridges


ikcdab
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Hi 

 

A question on how the layout will operate. Once trains leave the terminus, where do they go? Some trains can do a few laps then travel up the branch line, but what of the others? Did you consider a return loop or perhaps a reversible line in the fiddle yard and some crossovers?

 

Regards 

 

Nick

 

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p.s. John,

 

If you prefer a fixed diamond, one way to improve the wheel tracking is to raise the K-crossing check rails above the level of the running rails -- this is being done on the prototype nowadays.

 

For example by packing them with spacers, or using code 100 rail for them on code 75 track. This has a couple of drawbacks -- you can't use locomotives having flangeless drivers (causing also a problem for some preserved steam locos on Network Rail), and they are a nuisance when track cleaning. Also in a slip the ends need to be filed back down to avoid catching wheels on the slip road.

 

Martin.

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With the length of the switchblades, there is no reason why i can't have 8 slide chairs similar to an ordinary turnout. However, the greater divergence means that the slide chairs come up short and "run out" after 5. Advice received suggests I can make extended slide chairs, but a diagram kindly posted by @MartinWynne shows only 3 slide chairs. It is going to be "suck it and see" once I have the switch rails filed up. 

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37 minutes ago, stivesnick said:

Hi 

 

A question on how the layout will operate. Once trains leave the terminus, where do they go? Some trains can do a few laps then travel up the branch line, but what of the others? Did you consider a return loop or perhaps a reversible line in the fiddle yard and some crossovers?

 

Regards 

 

Nick

 

Hi nick you make some good points.  I'll give it some thought. My aim is not to pack in stacks of track and to keep large radius curves, so a return loop is out. But crossovers in fiddle yard might be desirable.

Ian

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  • RMweb Gold

So it has been a little bit quiet recently, mostly because I ran out of rail and was waiting for a further delivery. This is now turned up so we can start track building again, more about that later.

So I have been working on the electrics. This is going to be a pure dc layout, for no other reason than I actually quite like wiring and I enjoy devising and setting up sections etc. one of the things I learnt from my test track was to avoid too much work under the baseboard. Enough has been said on many other threads on here about the joys (?) of working upside down trying to connect wires under a baseboard. So the concept is to create wiring modules that I can work on the desk all of which can then just be plugged together and hey presto all should work. This has involved a fair amount of pre-planning and I have spent a lot of time working out wiring diagrams to show me what to do. Of course these will then be useful later if I ever need to do any fault finding but again the concept is that if I can build the modules on the bench I can test them first so fault finding should be minimal.

The general conceptis shown below, NOTE, this is diagrammatic only!

 

 

There will be four control panels, connected via six switch panels to the track. The switch panels carry the relays for polarity switching and connect to the route setting switches and signal switches on the control panel this is one of my switch panels.

 

20200904_120558.jpg.fc0d24ddc094fa7134b1231eb14877ce.jpg

 

on the left at the top the connectors labelled A to K connect directly to the droppers from the track. The yellow wires are then connected to the relays. On the right hand side the vertical connector joins up to the route selector on the panel. There is a diode matrix in the middle. When a particular route is set via the diode matrix the relevant relays switch and thus change the track polarity. Along the top edge, the connectors join to the servo drivers for the point work and the remaining connectors join to the servo drivers for the signals. There is a very small degree of interlocking via relays such that a signal cannot be cleared if the route hasn’t already been selected, again achieved via the two relays in the middle. Powered by 12v.

 

here are all the switch panels completed:

 

 

I have also been working on the control panels. Eventually there will be four of these though I have only built two so far. Again they are both prewired as you can see in the pictures below and should just plug in to the switch panels via the chocolate block connectors. Again I have been able to test these on the bench to ensure all is okay, or at least to minimise later faults!

20200904_120540.jpg.9db99a5f939444c5df2a0ddd995887ee.jpg

 

The Charlton bridge control panel is set up for cab control with the toggle switches the red and green LEDs indicate whether you’re connected to the red or green controller. Bottom right is the root selector which again operates via a diode matrix the through the various servos for the correct route the turnouts in the loco siding at the top and the good yard at the bottom have local control via the toggle switch and the rotary knob.

 

Rear  of Charlton Bridge panel:

20200904_120515.jpg.c45bd44d12e90991c5555a1ec96cd386.jpg

 

 

I think I am pretty much done with the two control panels and the switch panels for now so as soon as I can I will be back to track building. I might also over the weekend begin to assemble baseboards, who knows!

 

20200904_120458.jpg.ccec21fca22e0dee8291b8161b4a6144.jpg20200904_121615.jpg.85b6c28a66766f0e17aebcfc79080f0b.jpg

 

20200904_120458.jpg

20200904_121615.jpg

20200904_120540.jpg

20200904_120515.jpg

20200904_120558.jpg

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So control panels. Thought long and hard about this and learnt a lot from the test track. The panels are 1.5 mm aluminium sheet bought from an online supplier who will provide them to the exact size at a very reasonable cost. The diagrams themselves are created in my favourite drawing package, CorelDraw, and then rendered to PDF. Again I found an online printer who could print them out laminated at a reasonable cost. I tried several methods fixing the laminated sheet to the aluminium in the end settling on heavy duty double sided tape which appears to be holding very well, time will tell. The printouts were marked where holes need to be drilled for the switches and I just drilled straight through the aluminium sheet with the laminate fixed on top. This did produce a slightly ragged hole where the drill attacked the laminate sheet, but this was easily trimmed off with a craft knife and any resulting raggedness was covered up by the switch bezels. The switches are a mix of the various types, rotary and toggle as required.

Control panels will be mounted into a control desk at some point, this may well be a redundant dining table chopped down to a much smaller size.

 

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Ok so I have made some progress despite being hospitalised for an appendix removal, very painful. And now a very wet weekend.

The first step was to complete the second junction. This has the moveable diamond crossing. It was all a bit of a fiddle, especially as the rail I bought came slightly kinked. I should have sent it back, but decided to soldier on. This is now pretty much complete but I have just remembered I havent yet bonded the rails.

20201004_122046.jpg.f49ccbb5596c0ce20a64057231a04a02.jpg

 

I have also assembled the first part of the open baseboard framework.

 

20201004_122112.jpg.5058c823be45b92ccd8b18bae756241c.jpg

 

This was easy as it's all straight and square. A friend lent me a laser level to mark a level line around the whole room.

You will also see the first control desk, made from our old dining room table, cut down. The first control panel is mounted in this desk.

 

Both junctions now need to be fixed down.

 

20201004_122403.jpg.e632334e438cf606792e13b6edea8bb6.jpg

 

And then the joining track inserted. This joining piece does exist but is being glued to the ply sub base. When that's set, I'll align the three components together and fix down.

You'll see that the track here is raised up on spacers to get the required height and allow for "terra forming"

Ian

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So what's next? I want to get these first three track components down and trains running on this very limited section. The dropped area is for a viaduct, so I need to cut some piers to support that.

Then we start progressing round the rest of the room. That needs a little bit more thought yet. The baseboards are curved and so the horizontal members will all be different but precise lengths to get a smooth curve. My plan tells me what sizes they should be, but as it's a 1:10 scale plan, I'm not sure how well I can trust it to give me the exact dimension. It might need fitting exactly on site. Not sure yet!

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Some more progress. I have now assembled the other "easy" set of baseboard frames on the other side of the room. These are straight and 4.8m long. 

 

20201005_175054.jpg.43f4103f4ca2a12fcf34603e5651acfe.jpg

 

Pretty easy to do, I had made the cross members a few weeks ago. Only tricky but was holding it all up while I wielded the screwdriver.

Meanwhile on the other side of the room, I have completed the track bed components and fixed the carcase of the viaduct::

 

 

 

20201005_175117.jpg.7835c7d4799d135b50665d0ba6a76c15.jpg

 

I'm really pleased with the long be sweeping curve over what will be the viaduct.

 

20201005_175040.jpg.1f907aab009855807944fd1636ba0c0a.jpg

 

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On 06/10/2020 at 15:18, ikcdab said:

Next is the tricky bit, building the curved baseboards each end to join it all together.

I'm doing a trial run on one of them now, will report progress!

Ian

Ian,

 

This is a very impressive layout, on many levels. I can see you've done your planning very well and the construction quality is extremely good:good:.

 

Just one question, where is your 'other' shed? I can't believe you can keep a train room so tidy; there must be another 'room' somewhere with all the usual model making paraphernalia:sarcastichand:.

 

Ian

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On 07/10/2020 at 20:07, ISW said:

Ian,

 

This is a very impressive layout, on many levels. I can see you've done your planning very well and the construction quality is extremely good:good:.

 

Just one question, where is your 'other' shed? I can't believe you can keep a train room so tidy; there must be another 'room' somewhere with all the usual model making paraphernalia:sarcastichand:.

 

Ian

Haha well yes there is. The workshop is a 6m x 1.5m  lean to at the back of my garage. Originally this was going to be "the" layout and I started a 6m x 450mm end to end layout. Gave me just enough space to fit in the layout down one side and the work bench down the other, though it is a bit of a squeeze. I rapidly became dissatisfied with the layout that has now been relegated to the status of test track, hence the new shed and layout. I also have the garage that I use for the larger woodworking tasks. It's great having the three separate areas, but I spend a lot of time moving between them and the tool I want is always in the other shed!

Thanks for looking in.

 

20201009_094243.jpg.aec09c79b820fca806a90468f972625b.jpg

The less tidy shed with test track on left and workbench on right.

 

Ian

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Hi Ian, Well impressed is an understatement, this will be another Peterborough North / Grantham / Little Bytham / Hills of the North, in other words, a master project, and one well worth keeping an eye on, well done so far, very neat, well planned and organised.:good:

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13 hours ago, ikcdab said:

It's great having the three separate areas, but I spend a lot of time moving between them and the tool I want is always in the other shed!

Ian,

 

What I find very useful, in these circumstances, is a cutlery tray (or similar compartmentalised plastic tray), with a handle if possible, to keep the tools in. I only have to take that tray with me to have the tools I need, well, most of the time. 

 

Myself I only have 2 areas, the model railway room on the top floor of the house (up 2 flights of stairs!) and the separate garage. Thankfully, I only do the woodworking in the garage and once a baseboard module is complete it stays in the model railway room. All my storage is under the baseboards in large plastic boxes. To keep the carpet clean of solder balls, wire cuttings, and sundry bits of plastic offcut, I keep a cheap vacuum cleaner in the room.

Ian

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5 hours ago, ISW said:

Ian,

 

What I find very useful, in these circumstances, is a cutlery tray (or similar compartmentalised plastic tray), with a handle if possible, to keep the tools in. I only have to take that tray with me to have the tools I need, well, most of the time. 

 

Myself I only have 2 areas, the model railway room on the top floor of the house (up 2 flights of stairs!) and the separate garage. Thankfully, I only do the woodworking in the garage and once a baseboard module is complete it stays in the model railway room. All my storage is under the baseboards in large plastic boxes. To keep the carpet clean of solder balls, wire cuttings, and sundry bits of plastic offcut, I keep a cheap vacuum cleaner in the room.

Ian

Hi Ian, yes that sounds a good idea. At the moment my tools are electric saws, spirit levels, clamps, screwdrivers etc. 

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Well I have been working on the curved ends. I had been putting this off cos it seemed difficult to get the curve right without any kinks.  I had worked out the dimensions on the plan but I didn't know whether to trust it, given it was only a drawing. Anyway I had no real other option so I went for it. Mostly the horizontals all matched up apart from one.

This is the first curved section.

 

20201008_152706.jpg.4a2be18f49ec06d5c0666270ae10f203.jpg

 

View from other way:

 

20201008_152640.jpg.c756fa9cdd4b07cee548947e26b7baf8.jpg

 

I need to finish this off now. Hoped to do it today but it's a two handed job and I'm here on my own this afternoon. Hope to do it tomorrow.

 

Then I need to cut the trackbed to go on the frames. I will print out the templot plan and use it as a template to cut ply for the trackbed. Trouble is there's lots of it and many sheets to go through the printer then to stick up. @MartinWynne has given me some good advice over on the templot forum to minimise paper wastage. 

But for now still bashing timber frames....

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Hi Ian, Looking great, am currently refurbishing my HD Bristol Castle (an expensive exercise) but can't wait to see her stretch her legs if the Southern authorities allow. She arrived with me on Christmas 1957. Was reliveried as 5069 (IKB) in 1960. Reliveried again in 1966 but not named and sat for years wrapped up in news paper. She is now repainted and awaiting lining and is running well. Try to get out to see you soon. This new layout will be epic.

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1 hour ago, Kend said:

Hi Ian, Looking great, am currently refurbishing my HD Bristol Castle (an expensive exercise) but can't wait to see her stretch her legs if the Southern authorities allow. She arrived with me on Christmas 1957. Was reliveried as 5069 (IKB) in 1960. Reliveried again in 1966 but not named and sat for years wrapped up in news paper. She is now repainted and awaiting lining and is running well. Try to get out to see you soon. This new layout will be epic.

Hi Ken that's great, looking forward to it. Whether the castle will run or not depends on the wheel profiles. Will HD profiles pass through finescale flangeways?

Ian

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A bit more progress today. First bit of track laid, wired up and tested. 

 

Having pre-wired the relay panels made this all very simple.

 

20201013_183836.jpg.7c1361efe4adb9b58dd61254b1853f31.jpg

 

Signalbox is a temporary structure only.

 

20201013_183817.jpg.f91d922d91ebe19222776470dab06c11.jpg

 

The viaduct is the skeleton only. Cladding to come.

 

Ian

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  • RMweb Gold

OK, so its been a couple of weeks since the last update, but i have not been idle. Track laying has continued. I have built open frame baseboards and my track is on a continuous curve (i dont think there are any significant straight pieces) with transition curves. So  cutting the track bases accurately has been a key thing. 

I have used templot (well done and thanks again to @Martin Wynne ) and got it to draw both cess and baseboard edges. My procedure has been:

1. in templot, group together the templates i require for a particular section. Set it to plot on A3 and move the page origin to get the most economic use of the paper.

2. print it all out and stick the templates together. this needs to be accurately done and you end up with big bits of paper!

3. i then cut the templates down to the baseboard cut lines. lay the template over the ply and mark it out.

4. cut out the ply with jigsaw.

5, now stick the template down to 3mm cork. I have tried many different glues, but have finalised on spray mount.

6. now trim the cork/paper assembly to the marked cess line and stick it to the plywood base.

i have then been cutting the risers and fixing it al together with pva.

here is a picture of a completed storage sidings section ready for track laying:

20201024_111537.jpg.fc3a6c2d8a9e79fff6ac326a99cd9927.jpg

 

where the tracks curve round, i have been applying a degree of super elevation. This just looks so much more realistic that flat track. 

To do this, i have used a technique i found on line. 

1. i cut a double track section as per the steps above.

Then i cut down the middle of this, but left it joined together at either end.

Then i fixed it to the risers, but under the outer edes of each trackbase i inserted 2mm spacers. this means that the track itself is fully supported.

see:

20201024_111557.jpg.eaf30e9ff2681cee448e2fb854a5ccf6.jpg

 

In this picture, you can see the general curves. It really isnt tilted like this, i just held my camera at an odd angle!

 

20201024_111513.jpg.eef0b6ce9541199a58415b772e3e7248.jpg

20201024_111548.jpg

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I am gradually working, laying track around the room. The head of steel is approaching the storage sidings. these are just a fan of six loops approx 4m long. There are eight turnouts (4 each end) anmd as this is the storage sidings, these will be constructed from copper clad. Yesterday I cut the sleepers and glued them down. Cut the insulation gaps in the copper and began soldering.20201024_111548.jpg.e9243b3049e0d335965b1c9ce743917d.jpg

 

I am doing more work on these today, so will post again this evening.

in the meantime, all comments and questions are gratefully received!

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21 minutes ago, ikcdab said:

I am gradually working, laying track around the room. The head of steel is approaching the storage sidings. these are just a fan of six loops approx 4m long. There are eight turnouts (4 each end) anmd as this is the storage sidings, these will be constructed from copper clad. Yesterday I cut the sleepers and glued them down. Cut the insulation gaps in the copper and began soldering.20201024_111548.jpg.e9243b3049e0d335965b1c9ce743917d.jpg

 

I am doing more work on these today, so will post again this evening.

in the meantime, all comments and questions are gratefully received!

Ian C,

 

Looking really impressive! I admire your ability to cut the plywood trackbed to the alignment of the tracks.

 

How are you getting those printouts to be so perfectly aligned? When I inkjet printed mine, as a grid of A4-sheets (I don't have a larger printer), no matter how much care I took there was always 'some' small mis-alignments. Some sheets of paper were ~0.5mm different in size and, of course, there is no guarantee that the printer will print perfectly accurately in the right place on the paper every time.

 

How strong is your 'open' type of construction? On my layout (flat-ish plywood framed baseboards) I have found it necessary to actually climb onto the baseboards to be able to install tracks at the 'back' of the baseboards. Scenery access will be fine, but not the actual tracklaying.

 

Ian W

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