Gentle Progress

[richbrummitt]

I try to place the timbers under the crossing nose and the blade points and then fit the others inbetween as close to the proper spacing as I can manage. It seems to me that is how it would be done full size.

 

Pretty much. 

 

I recall that the spacing was not more than the usual (2'6") spacing from the nose to the switch and then not more than 2'1" for the length of the switch according to GWR switch and crossing practice. After I had done this I found that the difference was noticeable when you look for it, just like bring the spacing in at the rail joints. A few other details such as the length of wing and check rails are quite obvious too to someone who knows what they are looking at because they cover a particular number of timbers. 

 

 

 I guess we should get the discussion back on track

 

I have now printed out the plan full size. I am very impressed with the way the tracks curve through the station. Even more encouraging is the fact that a couple of baseboards I had built for a previous, failed project will be near ideal for the main station area. These were built open-plan. I would just need to widen the trackbed slightly in a few places and build a third board to cover the exit heading towards the Quay and an extra fiddle yard.

 

Originally , I was thinking of making the layout L shaped by building the extension to Lymington Quay, but I think that would definitely be a step too far.

 

Yes, sorry for my further diversion but I thought it would be of interest (maybe?)

 

I like the flow. Adding the extension could be something for the future. Make it achievable for now  

[Tequila Sunrise]

6 months of silence probably gives you a clue that nothing much has been done since my last entry in June.

 

The more I looked at my full-scale Templot plan of Lymington, the more unhappy I was with the idea. I decided it was too big for me to cope with. I also felt it lacked atmosphere - as did the alternatives I had looked at.  Something much more compact, but interesting was needed to stimulate my modelling appetite.

 

Nothing stirred my emotions until I came across a mention of a small turntable kit here.  To cut a long story short, I am now building one of these, adapted to 9.42mm gauge. The kit has so far been very quick and easy to put together. I modified the gauge from 9mm by gently filing the inside of the rails.

 

This is a photo of my progress so far. Some of the parts have not yet been stuck down and the motor has yet to be added. I will also make the planks look thinner by cutting extra slots between the current ones.

 

 

My plan is to build a freelance diorama around the turntable. The best arrangement I have found so far is from Waterford on the former Waterford & Tramore line in Ireland - though my fictitious diorama will be standard gauge. Here is a plan of the area around the turntable, with the platform line at bottom right.

 

 

There seem to be no photos readily available of the turntable area - it's a good job my model is not going to be closely based on the real location! Only the turntable at the other end of the line (Tramore) seems to have been photographed well.

 

The TT is only 60mm in diameter - slightly larger than a scale model of the real one at Waterford, but still very compact. This is plenty for small locos, but not big enough for anything longer. The good thing about Waterford is that the pointwork near the TT allows larger locos to run round their trains without having to turn the turntable. That is a flexible enough arrangement for me to live with.

 

Once the turntable is complete, I will finish planning the rest of the diorama in detail. It will be a compact branch terminus leading to a tiny 3-road fiddle yard I built several years ago.

 

The electrics will need some careful thought, as the 3 right-hand tracks overlap on the approach to the turntable. I think DCC will probably give me the best options.

 

Stock is likely to be BR 1960s, just like many other 2mm modellers, I am afraid! Building a layout and lots of scratchbuilt stock just is not an option for me with limited time at my disposal. Hopefully it won't be another 6 months before I have another entry ready for you all to read.

 

 

[Donw]

Life does rather get in the way sometimes. Now that small table has me thinking Ventnor - no Reg Dear did such a good job but Bembridge now there a thought. Anyway keep going on your diorama.

Don

[Tequila Sunrise]

Ta Don. I did think about Ventnor, but all those double slips make it a complicated thing to do!

 

Reading back through entry 27, I probably made it sound as if I hadn't a clue what I was doing, but a fair amount of planning really has gone into the track plan and photographic research.

 

I started by getting a track plan from the OSI site - Ireland's equivalent of old-maps.co.uk (though it works in a slightly different way). To get maximum clarity I paid for a downloadable map of the station area. From the digital map, I was able to work out the relative angles of the trackwork leading off the turntable. I then used this to draw up a plan in Templot.

 

 

I used the "make diamond crossing at intersection" option to draw in the crossing noses and wing rails. The detail in the centre of the crossing is not required as it is replaced by the turntable itself. I didn't bother editing this out, as it will be obvious when I build the track what is, or is not required. I think it will be easiest to build all the track around the turntable in situ. I will shorten most of the turntable roads to suit - apart from the tracks leading off to the right which are running tracks, loops and longer sidings.

 

The overall track plan will be based on this diagram, which more or less includes all the facilities that existed at Waterford....

 

 

The lower building is the station, with a train shed covering 2 roads. The upper buildings are a loco shed on the left and a carriage shed on the right. The diorama would be viewed by the public from the top side of the plan.

 

The only really big issues at the moment (apart from the electrics), are how long I should make the diorama and how much I should include outside the railway boundary. My strong temptation is to make the whole thing as compact as I reasonably can. It is largely a question of how short I dare make my trains. The real thing would be around 5-6 feet long, to scale, but I would like to reduce that as much as possible.

 

I hope the actual buildings within and outside the railway boundary will be to a different style to the real Waterford - partly to aid compression, but also to give the diorama a character all of its own.

[Tequila Sunrise]

I have conjured up a few improvements to the plan, so the track flows a little better. I did try very hard to compress the whole thing, but it sticks fairly rigidly to around 5ft, plus a small lead-in from the fiddle yard and a bit of scenery at the terminus end. This is in spite of me bringing the carriage shed and loco shed much closer together. Never mind! 2 x 3 ft boards will be almost as easy to carry and store as 2 x 2ft 6in boards or whatever, so it's not a huge problem.

 

The only thing I am really scratching my head over is how to wire the tracks around the turntable. The 3 tracks leading into the turntable from the right hand side overlap, with common frogs. The yellow track in the diagram below is the real issue.

 

 

The next photo shows a printout of the turntable approach, with the deck of the turntable laid on top.

 

 

Using DCC, a current reverser might work, but how to apply it without causing knock-on complications is doing my head in.

 

Otherwise, a manual DPDT switch might work, but remembering to switch it correctly will be a perennial problem. My only good fortune is that the middle road will act mainly as a siding, so it will be rare for a loco to run off this line onto the turntable, anyway.

 

The 2 roads leading off to the left in the photo will be electrically-dead roads, by the way - they could never be shunted by a loco, even on the real thing.

 

If anyone has any ideas, then suggestions would be welcome.

[Donw]

A two pole rotary switch is one possibility but would mean both turning the loco and switching the road. A two pin plug and an number of sockets would be another answer.  More complicated would be either wiping contacts or micro switches operated by the turntable to switch on the right road. A seperate switch would avoid electrifying each road in turn as it rotated which could cause parked locos to move.

With DCC a hex frog juicer would do the trick and shouldn't cause complications if you revert to normal past the crossing.

Don

[Tequila Sunrise]

Ta Don. Trying to think too late at night was likely my problem!

 

What I failed to grasp until this morning is that the 2 frogs can always be of opposite polarity to each other, no matter which road is in use.

 

So, attaching a frog juicer (or equivalent) to the 2 frogs should work well with DCC. For DC, a manual 2-way switch is probably the best option for the frogs - one way for the centre road and the other way for the two outside roads (and remembering to use it at the appropriate moment!). Either way, I think the shorter the switchable section of track the better - to avoid the risk of parking a loco where it is both on the switchable section and the normal track at the same time.

 

The turntable comes with its own electrical switching included in the kit, so no problem there.

 

I am still in two minds whether to go DC or DCC with this project. The article in the latest 2mm Magazine about stay-alives makes DCC very tempting for small 2mm locos - as does the way DCC copes with head and tail lamps for contemporary stock. I am not sure if the extra cost is justified for this particular project though.

[Nigelcliffe]

I'd be tempted to look at a microswitch (roller arm type) and a wheel on the shaft below the turntable.  As the turntable rotates the microswitch roller would drop into a detent in the wheel, altering the polarity of the tracks.   Use of a handful of microswitches should cover all eventualities.  If out of space for multiple switches for both poles, then relays can be used to increase the number of poles (though stacking switches side-by-side usually does the job).  Its cheap, simple, reliable, not tied to mechanism to rotate turntable, and works for DC or DCC.

 

Another possibility is to use whatever switch which operates the rotation of the turntable to also set the polarities correctly. 

[Tequila Sunrise]

Ta Nigel.

 

Great avatar by the way - or is it just very foggy where you live at the moment?

 

Following yet deeper perusal, I have drawn up a diagram to illustrate the polarity issue - just to make sure I have things clear in my head. I believe the matter is really quite simple. None of the tracks around the turntable require special current switching, apart from the 2 frogs and associated track in the middle of the 3-road convergence on the station side of the turntable.

 

In the illustration, I have shown in red and blue how the current needs to be reversed - the upper diagram shows the polarities necessary for the 2 outer tracks to be operational. The lower diagram shows the minimum necessary for the middle road to be operational.

 

 

So, as I see it, all I need is one 2-way switch (by whatever means) - centre road or outer roads.

 

The turntable too will need current reversal as it rotates, but that will be dealt with separately.

[StuartM]

You could use a 3 way dpdt and number the positions 1,2,3 corresponding to each road

Then everytime you want to use a particular road, you set the switch accordingly

This would also help isolate the roads when not in use, which would be useful if using dc

[Tequila Sunrise]

I hadn't included section isolation in my thinking, so many thanks for the suggestion Stuart.

 

Looking at a diagram of the whole area however, I am not sure that combining the isolation and polarity issues would work for me. The only places where a loco might need to be isolated close to the turntable (under DC) would be on roads H or I. For every other road, locos are unlikely to be parked near the turntable at all.

 

Conversely, a short section of the track on H and I immediately by the turntable needs to be live in case a loco comes from A/B or D/E and just overruns the turntable by a small amount. These locos would not necessarily be using the turntable to turn - just as a headshunt, as they switch from road E to road D or A to B, for example.

 

 

My thinking at the moment is that, under DC, I would need to keep the isolation of locos separate from track supply issues around the turntable. Ultimately, I may yet form an opinion that DCC is best for this project, so the issue may become purely academic!

[Nigelcliffe]

Yes, it is as simple as you describe, just a DP changeover for the centre road.    I still think its easy with a microswitch on a disc/wheel below the surface on the same shaft as the turntable.  One detent required, as the middle road lines up, and reverse the polarity of the two crossings.  I'd fix two normal microswitches together, and arrange both rollers to connect with a large-ish rectangle of wood bolted to the rotating wheel.  The wooden rectangle can be adjusted for exact position.   Should be totally reliable once installed.   Same system for DC or DCC. 

 

( I just have a thing about wasting screen areas with pointless pictures, so created a 1-pixel picture ).

 

- Nigel

[StuartM]

I hadn't included section isolation in my thinking, so many thanks for the suggestion Stuart.

 

Looking at a diagram of the whole area however, I am not sure that combining the isolation and polarity issues would work for me. The only places where a loco might need to be isolated close to the turntable (under DC) would be on roads H or I. For every other road, locos are unlikely to be parked near the turntable at all.

 

Conversely, a short section of the track on H and I immediately by the turntable needs to be live in case a loco comes from A/B or D/E and just overruns the turntable by a small amount. These locos would not necessarily be using the turntable to turn - just as a headshunt, as they switch from road E to road D or A to B, for example.

 

TT-Routes.jpg

 

My thinking at the moment is that, under DC, I would need to keep the isolation of locos separate from track supply issues around the turntable. Ultimately, I may yet form an opinion that DCC is best for this project, so the issue may become purely academic!

 

If it we're me, I'd make A/B section 1, C section 2,  D/E section 3 and I'd make the turntable and it associated sidings an isolated section all of its own wired into the DPDT switch, so the turntable would always be live to which ever other section was in use

[Tequila Sunrise]

Ta both for the additional input.

 

The turntable and the permanent way must be completed before I may contemplate installing the electrics. This allows an abundance of time for my subconscious mind to mull over the electrical opportunities and come to a fitting conclusion.

 

Meanwhile, I am minded to try and finish the turntable this evening. Then, it will be time to call in the navvies for a bit of complex track construction.

[Tequila Sunrise]

 

( I just have a thing about wasting screen areas with pointless pictures, so created a 1-pixel picture ).

 

- Nigel

 

There can be no doubt that it makes my own avatar seem offensively bright

 

[Tequila Sunrise]

The turntable is now more or less finished and ready for installation. I temporarily attached the motor to the included battery power pack. It rotates successfully. I may slow it down as the 2 x AA batteries seem to make it revolve just a little bit too fast.

 

 

I have not yet fitted the top deck to the turntable. I may scratch build something more closely resembling the Waterford & Tramore ones, like here at Tramore...

 

 

...but that can wait until later.

[Tequila Sunrise]

I have now made a dummy battery to replace one of the AA batteries in the turntable battery holder. I did think I might have to cunningly paint it to look like a real battery in order to fool the rest of the electrical system but thankfully, the battery holder and turntable were easily fooled into thinking nothing suspicious was going on! Now, the turntable takes around 40 seconds to do a complete revolution, which looks much better.

 

 

At just over 60mm long, my new "layout" must be the shortest on RMweb, if not in the whole world. The operating potential is a bit limiting, to say the least........

 

 

...I must get on and build some more track!

 

I have been looking into the baseboard question. A quick trip to the baseboard graveyard in my spare room produced a small experimental board around 42in long and 13in wide. I could use this to reproduce most of the scene. I could then either take the 3 remaining tracks straight into the fiddle yard, converging on a sector plate, or build another board to complete the country end of the station and its approaches in their entirety. Either way, at least I have something to start on.

 

I think the scene is best modelled narrow, rather than wide. In front of the railway, there was little of note. Behind the station, nothing much would be visible for quite a way back anyway, so I may as well just have the backscene close to the railway boundary.

 

It may take a little while before further significant progress is achieved. Please be patient!

[Tequila Sunrise]

The TT has been temporarily fitted to the trackbed to see how easy it will be to use.

 

 

Unfortunately, it still revolves too fast, despite me dispensing with one of the batteries. Even the slightest touch of the wires moves it too far to allow me to make minor corrections to the alignment. I now feel it ought to go half as fast, if not slower.

 

I will experiment with resistors next - I think I have a few somewhere in the treasure chest. It will be trial and error though, as this kind of thing is a bit of a dark art to me.

 

[Pixie]

Hi Mr Sunrise,

 

That's some nice progress there!

 

I've used banks of diodes in the past to drop voltage, after having a problems with DCC point decoders throwing out too many voltages for my poor little Tortoise motors. Soldering a pair of diodes in parallel to each other, but 'pointing' in opposite directions to allow current both ways, drops around 0.7V per pair. These pairs can then be added in series to further the drop the voltage.

 

Pix

[Tequila Sunrise]

Two progress reports in one evening is seriously crazy for me, but here we go with number two....

 

Thanks, Pixie. When I said resistor, I really meant diode - just shows how dumb I really am!

 

Here is the one I tried - though I do understand I need 2 parallel diodes set opposite ways around for the TT to revolve both ways.

 

 

They are labelled IN4005GP and 8022, whatever that means. They are probably very old.

 

Anyway, they seem to be just the job. Here is a video showing the TT in action. Sorry for the wobbles, but I was having to hold 2 wires together in my fingers at the same time as I was holding the camera. Any jerkiness is due to the wires not being held together very well.

 

http://youtu.be/rvbjmjRaCkY

 

Once the TT is properly installed and hard-wired, it should be smooth and easy to control - not to mention being a lot easier to video. I won't do all that until at least some of the track has been installed. I need some track in place first, to make sure the TT rails are properly aligned and at the right height.

 

The critical bit is the 3-way crossing right next to the TT, so no prizes for guessing what I will try to do next.