Category: Electronics

Our Model Railway Club is starting a new 009 (Narrow Gauge) layout and we needed a couple of control panels to control it. Being a small layout, it is much simpler than previous designs and small enough to 3D print.

The first stage was to design the front panel layout:

As this is designed to be used from either the front and the back of the layout, there is no text on this as it will be used “upside down” at the front. This was printed, then holes punched out for the LEDs, then laminated, then holes punched out for the switches.

The next stage was to design the case. The vents in the bottom part were added in case the electronics got a bit warm:

The switches and LEDs are fitted to the top section and marked:

Then the ribbon cable that connects to the control board is fixed using the cable clamp printed earlier:

The LEDs are wired first, then the switches:

The control board is screwed to the bottom of the case and a power/signal cable added to connect it to the layout:

Then the two parts are connected and tested:

The two parts of the case are then screwed together:

And a final test done:

The switches are spring loaded “centre-off” switches as the LEDs can be changed from the other control panel or other sources. Once the layout is built, servos will move the points as indicated by the LEDs.

 

There has been a level crossing by the halt since the beginning of the railway:

The gates could (just) be moved manually, but it was very difficult to keep the track across the crossing clean.

When the track was relaid in 2017, I made provision for a new crossing with a large hole cut in the baseboard:

Tracks were soldered on a large piece of copperclad board, with the whole assembly fixed to the layout with bolts:

The new track was laid to match the crossing tracks. Temporary covers were put on the crossing:

Fast forward to 2019, with the first attempt at automating the gates:

This never worked particularly well, so didn’t move past the prototype stage.

Occasional attempts were made to improve things using a variety of different approaches. Finally, in early 2022, a reasonably successful implementation was made, using a variety of 3D printed gears and brackets:

This used the same Peco gates as the original crossing, but with an operating wire carefully inserted into the post of each gate. The lead on the left connects track power and servo control signals to the main layout.

This was then installed on the layout, with some of the top covers reprinted for more reliable operation:


Here is a short video showing the crossing in operation:

The roads and associated scenery will need some tidying up at some stage!

 

Just before lockdown, I took home one of the club model railway boards that I had been working on. As the club was to be closed, I also took a selection of club materials to finish the scenery in all the spare time I (didn’t) have.
The first job was to add some buildings and walls, and tidy up the grassed bank and steps. I also used the club Static Grass Applicator to add some “grass” behind the road:

I also added a couple of fences:

The next job was to apply “grass” to the rest of the board. I was unconvinced that the club applicator was working properly, and another one that I borrowed didn’t seem to be much better. These work by generating a very high voltage, and using static electricity to attract the “grass” onto a layer of glue, the idea being that most of it sticks up rather than laying flat.

In the end, I tried adding  a metal tea strainer to the club applicator – this looks rather unprofessional, but worked much better:

I then used this to make some grass “clumps”. First off, a couple of bits of wood with holes in are clamped to an aluminium sheet, then small dobs of PVA glue added in each hole with the cocktail stick:

The grass is loaded into the tea strainer and the electricity switched on:

When the strainer is shaken, the fibres are attracted to the metal sheet and the holes gradually filled up. The fibres also go everywhere else of course, so need to be swept up to be reused:

Once the excess is shaken off, you can see the filled holes:

This is repeated a few times with different ‘grass’, then the wood frames are carefully removed, leaving the clumps on the metal sheet:

And in close up:

Once the glue has dried, these can be popped off the sheet and glued into place on the layout.

Part 2

I then decided to buy my own Static Grass Applicator so that I could use it on my layout. I found a ‘tea strainer’ sort for sale, but it didn’t seem to work very well. A bit of research revealed that it was a modified electric fly swatter, and didn’t produce nearly enough voltage to move the fibres. With help from a colleague, I rebuilt the circuitry inside to double the voltage output to -3.4KV, and it now works far better than the club one!

The cover on the tea strainer is good as it stops the fibres flying out of the top of the tea strainer:

Now all the bits are in place, all I need to do is finish the club layout board!

 

One of my background tasks for the last year or two has been building an Automated Level Crossing to go by the halt. There are various designs around, but many are very complicated and often too deep to fit under the baseboard.

This shows the gates on the current prototype – it operation, they all move so that they close either the tracks or the road:

Underneath, it’s a bit more complicated:
Each gate is mechanically connected to a servo using a pair of gear wheels. The servos have small motors that are driven by the electronics in the middle.

The end position of each gate can be independently set using the small push buttons on the electronics board. The speed of movement can also be programmed.

Originally, this used standard servo arms to connect the servos to the gates, but these didn’t move the gates to the exact position reliably.

I spent a while looking for better solutions, then looked at various designs of gear wheels on the internet, found something the right size and then printed them on the 3D printer:

They are a bit rough, but serve the purpose and seem to work well.

Now I’ve got the mechanics right, I need to find some better level crossing gates before adding it to the layout.

 

There used to be signals on the exit of each goods yard, but these were really not the right sort, so when the track was relaid, these were removed.

I recently found some that were the right sort, and these have now been fitted to the layout:


And the signal colours change with the points…

As the track layout has now changed, the existing mimic panel was out of date. It needed rebuilding anyway, so it was easier to start from scratch with a new panel. This panel also shows the state of all of the layout signals.

This uses a sandwich of 2 sheets of 3mm clear Acrylic sheet with the printed layout between them. The holes for the lights are just drilled in the rear sheet, with holes for them cut out in the paper.

The new panel fits into the same wooden frame on the windowsill that the old one used.