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You might look a little out of place out in the evening.  Girls in stilletto's, short mini skirts and not much else, no matter what the weather is.  Better take yourself some shorts and T shirts in case you venture out.........

We're not postmen...

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  • 4 months later...

I reckon this is one of the best layouts I've seen online and at exhibitions looking at the photos of the layout! So realistic, something that I'm struggling to achieve on my own N gauge layout  :scratchhead:

 

How do you achieve such good lighting in all of your photos? Do you have a light bracket above the layout or are you taking the photos in natural light? My layout photos come out all dark and artificial, although it's not as bad now that I'm using one of those ultra bright bulbs!  :boast:

Layout is superb, really is one of the best I've ever seen, if not thee best!

 

Cheers, keep up the amazing work!

Matt

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Thanks for the compliments Matt. I don't think any of the photos on this thread have been taken under natural light in fact the vast majority are taken in my workshop with just the normal neon tube room lights. The layout does have a lighting pelmet for exhibitions which is also neon tubes so hopefully the colours are the same when we are out and about.

 

One of thhe keys to good pictures is the exposure. Earlier in the thread I was using an Olympus crossover camera but latterly a Nikon D3100 DSLR. Not expensive equipment. I (almost) always use a tripod and long exposures, sometimes as long as 15 seconds. I use the shutter release self timer on the camera so I am not touching the camera at all when it opens the shutter and therefore avoid any camera shake.

 

I tend to add something like +0.7 to +1.3 of exposure compensation and either use auto white balance or set the white balance for neon tube lighting.

 

I throw away a lot of pictures that are not good enough!

 

Cheers

Dave

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Cracking layout Dave, I'm just starting off on the big adventure in n gauge and hope mine can look as good as yours, I will be going back to the beginning of this threat and walking through your tips and expertise

 

I am sure if I get stuck on the way this forum will help me

 

I hope to see Waton in the flesh soon

 

Graeme

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  • 5 months later...

It's been ages since I posted anything here but today I have been tinkering with the layout as we are due out to the Farnham and District MRC exhibition at Aldershot next weekend. Not done all the boring things like cleaning yet but having fun adding a few more road vehicles and people.

Whats going on here?

post-7010-0-88900300-1504802778_thumb.jpg

Somebody is having a bad day...

post-7010-0-30495500-1504802792_thumb.jpg

Somebody needs to get on to the council about clearing up the rubbish around the recycling bins...

post-7010-0-74668800-1504802807_thumb.jpg

I doubt anyone has ever noticed these two blokes tucked away behind the station building...

post-7010-0-59491300-1504802818_thumb.jpg

The fire engine?  Must be to deliver water to Oliver Cromwell...

post-7010-0-51809100-1504802831_thumb.jpg

Anyone coming to Aldershot feel free to drop by and make yourself known.

Cheers
Dave

Edited by eldavo
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  • 2 months later...

Waton is due out next in January at the Southampton MRS exhibition at Barton Peverill College in Eastleigh.  The layout hasn't been unpacked since it returned from Aldershot so that's something to do in January.  I always try add something to the layout each time it goes out so what should be added this time? Nothing on the scenic side of things has particularly taken my fancy but it occurred to me that the layout has working signals and the majority of the locos have headlights but none of my freight trains have tail lights!

 

There are commercially available tail light units but most seem to require a battery and are invariably for US prototypes.  As my stock comes out the box a couple of times a year I don't want to have to fiddle around fitting switches and batteries.  If Waton was DCC things would be easier as the tracks would be powered all the time but it isn't so I need a solution that allows a train to sit out on the scenic section for several minutes with no power yet still have a flashing tail light.  Seems like a job for a supercapacitor or two.

 

Trawling around the interweb I cobbled together a circuit based on other circuits for coach lighting and flashing tail lights.  Hopefully this circuit allows the use of DC or DCC and will, assuming I can fit a large enough super capacitor in the stock, keep working for some minutes after the track power is cut.  As there is no battery this wont need changing and as it will recharge when there is track power there is no need for a switch to save power.

 

I'm no electronics engineer so go easy on me!

 

post-7010-0-72501400-1481488326_thumb.jpg

 

The basic idea is that the track power is fed through a bridge rectifier, the 4 diodes on the left of the circuit, to a voltage regulator to provide a steady 5 volts.  The bridge rectifier means the circuit can deal with DCC or whichever way the DC feed is delivered.  As long as there is something over 5 volts on the track, reliably probably anything over 7 volts, we should get a 5 volt supply.  There is a smoothing capacitor across the 5 volt supply and a small resistor to limit the in rush current when the (optional) super capacitor starts charging.  The 5 volt supply is fed to a fairly simple circuit based around a 555 timer IC which then flashes the LED.

 

The voltage regulator is needed as small super capacitors tend to be designed for 2.7 or 5.5 volts and the volts coming off the bridge rectifier can be substantially more than this.  If we were building this for DCC only use then we could do without the regulator and things would be simpler (and smaller).

 

The circuit was drawn up in DesignSpark PCB which was then used to layout a circuit board. As this has got to fit into N gauge stock I have used surface mount components to get the size down.

 

post-7010-0-00049300-1481490915.jpg

 

I haven't etched my own circuit boards for 45 years or so and then the circuit was hand drawn on the copper and etched with acid.  I remember my teeth aching for days after getting a mouthful of acid while decanting the stuff using a pipette!  These days there are all sorts of UV sensitive copper boards and etch resist films you can buy but being a cheapskate I didn't lash out the cash.

 

I blagged a freeby laser printer that was being binned by our railway club chairman and used it to print a mirror image of the copper tracks onto some glossy magazine paper (in this case a page out of the December 1972 Railway Modeller).

 

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It's interesting to see that this technique works even though the circuit board image has been printed over the top of some printed matter.  The blank PCB board was given a rub over with a glass fibre scratchy brush and then wiped with Isopropyl alcohol to remove any tarnishing or grease.

 

post-7010-0-80965900-1481491572_thumb.jpg

 

The printed image was then placed face down onto the copper surface and smoothed with a cloths iron at max heat for 2 or 3 minutes.  I had to do this when the authorities weren't looking as she believes I don't know how to use an iron!  The laser printer ink is bonded to the copper.

 

post-7010-0-49388500-1481492048_thumb.jpg

 

The result was then soaked in some water with a touch of detergent until the paper removed easily from the copper leaving the laser printer ink bonded to the copper to act as an etch resist layer.

 

post-7010-0-32272600-1481492178_thumb.jpg

 

more to come...

Edited by eldavo
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With an etch resist layer on the copper it was time to look at etching it.  First up the board was cut from the rest of the PCB sheet.  It's small but putting it next to an item of stock it's intended for it still looks pretty big...

 

post-7010-0-33063200-1481493389_thumb.jpg

 

Rather than using nasty dangerous acid as I did in my youth this time I used Ferric Chloride to disolve the unwanted copper.  A small amount of the etchant was put in a glass container which in turn was sat in some warm water to speed things up.  The board was then submerged in the solution and swirled around for several minutes until the copper had gone.

 

post-7010-0-98686000-1481493549_thumb.jpg

 

The resulting board looked like this...

 

post-7010-0-02087900-1481493643_thumb.jpg

 

To remove the laser printer ink I rubbed the board with Isopropyl alcohol which got rid of most of it then used a very light touch with the fibreglass brush.  The tracks are very small and delicate!  Unfortunately my wife doesnt wear nail varnish other wise I could have used nail varnish remover, acetone, which would probably be more effective.

 

The next challenge is to solder the TINY components to the board.  For the first attempt I used standard multicore electrical solder and my standard iron which worked but was more difficult than necessary.  For the seconds and subsequent boards I have used a solder paste and a smaller 15watt iron which makes the whole job much easier. The most difficult part of the project is getting the solder paste in the right places on the board.  Once it's there the components can be positioned with tweasers and they stay in place reasonably well.  A delicate touch with the iron and the solder melts and flows almost instantaneously.

 

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There are other ways to melt the solder including using an oven, putting the board on a griddle or using a hot air gun.  To remove any components for rework or after mistakes you pretty much have to use one of these methods or you will end up wrecking the board.  I used an old Black and Decker hot air gun designed for stripping paint and this melted the solder quite quickly.

 

Eventually after 3 attempts I managed to assemble a working board.  Attempts 1 and 2 only failed because I made mistakes. Below is my latest attempt being tested and it flashes away happily.  The LED is an 0802 package and is the tiny blob on the end of the enamelled copper wires and I even managed to catch it illuminated red. 

 

post-7010-0-79522500-1481494504_thumb.jpg

 

I'm now awaiting delivery of some small super capacitors and then it will be time to fit the unit into the dummy class 67.

 

Cheers

Dave

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A couple more days and a bit more progress on the flashing thingy. The super capacitors duly arrived and a bit of testing showed the board design worked. Whoopee. Of course while fiddling around I managed to do something really stupid. I went to unsolder a connection while the board was powered up and following a sharp crack and a spark the lights went out.

 

A bit of poking around with my multimeter identified that I had fried one of the diodes in the bridge rectifier and after replacing it the little beastie came back to life. Phew.  I duly set about installing the unit into my dummy class 67.  Guess what, I only managed to go and make the same mistake again.  DOH!

 

After the second flash it wasn't clear just how much of the board I'd managed to fry but at least two of the diodes were toast.  I decided to move on and build another one.  In fact I've etched a batch of four boards.  I know how to have fun!

 

When it came to soldering I thought I would try something similar to the way real boards are produced.  I blobbed a dab of solder paste on each of the contact pads.  Surprisingly you don't have to be too accurate over this as long as the blobs (technical term) aren't too big. When everything melts the solder tries hard to get to the copper tracks and the tinned pads of the components.  With the solder paste in place it was on to the tricky bit, placing the components.  They are so small that the paste is sticky enough to hold them in place. Just don't sneeze or be too heavy handed with the board with the components on. Ask me how I know.  Below are a couple of shots of the board with the components balanced on the solder paste.

 

post-7010-0-72488400-1482011271_thumb.jpg

 

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The second shot was taken through the close-up lens of my magnifier to try and get the camera on my phone focussed in close enough.  To do the soldering the board was placed on a convenient brick (doesn't everyone have bricks in their workshops?) and my trusty old Black and Decker hot air paint stripper wafted close to it for about 30 seconds.  It is a strangely satisfying sight seeing the solder paste turn from a mucky grey colour to a shiny metal and bond all the joints.  It's magic...

 

post-7010-0-90857700-1482011617_thumb.jpg

 

This all went rather smoothly and so it was on to installing the beast into the class 67 (again).  No big problem as there's plenty of space in there.  A 0.7mm hole was drilled through the front of the loco where the lamp iron is and the LED leads fed through and soldered to the board. The LED was painted white and super glued to the front of the loco.  Being a Dapol dummy loco the bogeys conveniently have pickups so a couple of enamelled copper leads provide the track feeds. A bit of plastic was scooped out of the chassis for the super capacitor and we were done.

 

In this case I have used a 4 Farad 5.5volt capacitor which is really small.  It's only about 6mm in diameter the down side being they are about 6 quid each.

 

post-7010-0-33232200-1482011950_thumb.jpg

 

So quite a lot of work for what?  It flashes...

 

 

Having to use a 4 Farad capacitor is a bit of a pain as the cheap ones are too big for N gauge so using less power would be good. So far I have used a general purpose 555 IC which is a bit power hungry (according to those that know on the interweb) so I may investigate low power options. I'm frankly amazed it works at all so we shall see whether the project just gets shelved.

 

Cheers

Dave

 

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So it was all working(ish)...

 

As always as soon as I think I have something sorted I find a better way of doing things and start all over again.  The first version of the flashing tail light thing worked OK but as the 555 circuit was a bit energy hungry I needed to use a BIG expensive capacitor to get the duration of unpowered operation I wanted.  I was also using a 5 volt regulator which is both a bit physically big and also needs 6 or 7 volts at the track input in order to kick in and get the super capacitor charging. Not good enough.

 

A bit more surfing of the interweb and I found some coach lighting circuits and other stuff that held the answer.  Instead of using a voltage regulator all that is needed is a zener diode to limit the voltage being delivered to the supercapacitor and the timer circuit. Much physically smaller.

 

After digging around I also found a low power version of the 555 timer chip.  This chip will operate on a voltage as low as 1.5 volts.  Therein came a lightbulb moment.  Instead of using a 5.5volt supercapacitor I could use a smaller cheaper 2.7volt version, just need to use a 2.7volt zener diode instead of a 5.5volt version.  Seemed like a winner all round.

 

Below is the modified circuit...

 

post-7010-0-33917200-1482614269_thumb.jpg

 

From this a came up with a board layout which turns out to be about 25% smaller in area and also thinner...

 

post-7010-0-08934600-1482615078_thumb.jpg

 

At first I used a conservative value for the inrush current limiting resistor, R1, of 820ohms but this gave too long a charge time for the capacitor.  I tried values down as low as 10ohms which gave swift charging times without the current getting too huge but this still managed to trip the short circuit protection on my layout controller.  Currently I have a 47ohm resistor in place which seems to be acceptable to the controller but gives a pretty quick charge up.  When enough power is applied to start a train creeping forward the tail light starts to flash almost immediately and in the 10 or 15 seconds it takes for the train to travel from the fiddleyard to the scenic section it picks up enough power to keep flashing for about 10 minutes stationary.

 

below is a pic of the modified class 67 installation with the modified circuit and a 2.7volt 1.5 Farad supercapacitor.

 

post-7010-0-28266900-1482615901_thumb.jpg

 

Looking at the board above you can see there is a fair bit of empty or poorly used space in the layout. The observant will even spot that it's not the same as the layout shown higher up the post. The next boards to be built will be even smaller! You can also see a rather clumsy 1/4 watt resistor hacked on. This is the 47ohm inrush current limiter. I need to source some smaller ones!

 

Have a good Christmas all.

 

Cheers

Dave

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Just one more flashing tail thingy installation shot. Any more and everyone will be asleep. This is a Farish steel wagon. I've fitted pickups to one of the bogeys but there's plenty of space for all the gubbins.

 

post-7010-0-23611600-1483132780_thumb.jpg

 

This is probably my final design of board and it's much more compact than earlier versions. I've built four of these and they all worked first time and only took 15 to 20 minutes to assemble using solder paste and the hot air gun. They are all using cheapy Chinese 1.5 Farad 2.7 volt super caps and do the job quite well.

 

Interestingly this board design is dual purpose. In the version I've been using the charging voltage to the supercap is regulated by a zener diode. If the zener diode is replaced by an SMA package 1 microfarad electrolytic capacitor and the supercap is omitted hey presto you have a DCC version.

 

So far I have 4 units installed and 4 more to go ready for Southampton exhibition. Of course I'm now looking at the locos and getting disatisfied with the way the headlights go out when the train stops...

 

Cheers

Dave

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Having seen these in the flesh today, so to speak, I have to say they are impressive. For me, having seen so many things in 2mm/ n scale that are modelled oversize the fact that these are scale size to the originals make them even more of an achievement.

 

Clever s*d....

 

 

 

 

Derby line signal still only shows a red aspect though......

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  • 2 weeks later...

Having sorted out 8 flashing tail lamps (almost) I thought it might be a good idea to take a look at the layout's snagging list from the last outing. Bit radical I know.

 

A thing that has bugged me for a while is the microswitches I have used for switching the polarity of the frogs on the pointwork.  All the points on Waton are operated by servos so there is no built-in frog polarity switch and so each servo has a small microswitch mounted on it which is operated by the servo horn. The switches have worked fine electrically but mechanically they have been a bit of a pain. Several of them have simply fallen apart during transportation of the layout. Fitting replacement switches under the layout while trains are running at an exhibition is not my idea of fun and as yet another had failed on return from the last trip it was clearly time to do something about it.

 

The pic below shows the underside of one of the fiddleyard baseboards with 8 servos and attendant microswitches and wiring...

 

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Looking in close-up you can see the microswitch mounted on the servo mount. You can also see quite a lot of lazy man's cable clips (hot glue!)...

 

post-7010-0-68844500-1484511480_thumb.jpg

 

All the servos are driven by Arduino boards and each point is switched by clamping a control line to 0 volts. There are a number of relay units available that are designed for use with Arduinos and similar which operate by clamping a line to 0 volts.  What a fortunate coincidence. These units are also extremely cheap if you order them direct from China. I couldn't buy the components for the price! Of course if you decide to rewire the layout 2 weeks before the next exhibition you can't wait for stuff to come via cheapo China post and have to use local suppliers and pay extra. Doh!

 

Still I managed to source a number of 8-way, 4-way and 2-way relay units with next day delivery so the job was at least possible. All the microswitches were ripped out and the wiring adjusted to route to the relay units along with 5 volt and 0 volt supplies. I can't claim the wiring is any neater after the work but hopefully the mechanical characteristics will be better.  A side effect has been that the servos seem to buzz and chatter less as they are not working against the microswitches. It better be an improvement as rewiring 37 switches on 7 of the 8 baseboards took quite some time. The pic shows how the board above looks after the work...

 

post-7010-0-70371800-1484512395_thumb.jpg

 

I've also fixed a couple of niggling problems including a dead section of track that seems to have survived for 6 years undetected. Now I need to do some serious shake-down testing.

 

Cheers

Dave

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Well I was never going to spend very long testing things but it mostly seems to work. I've serviced a few (6) spare class 66s and they are now probably useable. Just as well as I have a casualty, Dapol 66720, which is dead with a short circuit across the motor. Annoying as it's not that old. Grrr.

 

On with other stuff then. One of my operating team who shall remain nameless but who spends quite a lot of time drinking tea, on seeing the flashing tail lamps pointed out that the steam special should have a high intensity headlight! I hate it when people set challenges...

 

post-7010-0-04580700-1484945696_thumb.jpg

 

So Oliver now has a representation of a Dorman battery headlight and a couple of headcode lamps. Again it's an 0805 surface mount LED, this time white, rigged to a simple electronic gizmo with a supercapacitor to provide power when the train is stopped with no power.

 

The Dapol Britannia doesn't have a lot of spare space in the loco. I could have just about fitted the bits in the cab but that would make reattaching the drive shaft (which has a habit of falling out) more difficult. I opted to stick the gubbins in the tender. The enamelled copper wires from the LED run underneath the loco to a scrap of copperclad tucked away above the rear pony truck. The pic below shows the wiring being routed around.

 

post-7010-0-54773800-1484946176_thumb.jpg

 

A pair of wires run from the copperclad back under the tender then up into the motor space. If I ever need to separate the loco from the tender these will have to be unsoldered but that is an unlikely event and I would have to detach the pickup wires anyway.

 

The nasty cheap Chinese built Dapol circuit board and DCC socket is long gone on this loco. It went back to the manufacturer twice with short circuits on that abortion of electronics work so I ripped it and skipped it and the loco has run like a charm ever since. This frees up some space but there is still a bit of stuff to fit...

 

post-7010-0-16388200-1484946515_thumb.jpg

 

The circuit board is a simplified derivative of the flasher unit with just a bridge rectifier, a zener diode and a couple of resistors. I could probably do without the bridge rectifier but would still need a couple of basic diodes to stop power being fed back to the track and the supercapacitor being fed reverse voltage. They don't like it up em!

 

As with the flasher unit this will work with DC or DCC and could be used for coach lighting. Omitting the supercap and switching the zener for a 1uf electrolytic capacitor would provide a simplified DCC lighting circuit.

 

I think I've had enough of building lighting circuits under a magnifier for a while now. Time to tinker with some other bits and clean things up for next weekend.

 

Cheers

Dave

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Good man, looks the business. Ummmm, coach lighting....

 

As for the tea drinking I seem to recall that whenever said operator has a cup the boss does too. Strange that...

Edited by PhilH
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  • 1 year later...

Waton has been boxed up in a corner for over a year but is due out for a one day show at Fareham Rotarail in two weeks time. Better assemble it and give it a bit of a clean up.

 

I've been working on some new stock but I think I may have made an error in scaling the drawings...

 

post-7010-0-44422900-1523826034_thumb.jpg

 

Cheers

Dave

 

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  • 1 year later...

Waton has been abandoned crated up in a corner of the workshop for another year but it's due out to Brockenhurst exhibition this weekend.  Stop by and have a chat if you are in the area.

 

Cheers

Dave

 

waton_may19.jpg.31ab744f2ef7eae5c5781b39d654dc94.jpg

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