This Blog describes the ongoing development of a 16mm scale 45mm gauge garden railway situated in the North West of England, UK from 2004 to the present day.
This blog describes ongoing progress in the development of a G gauge / 15mm scale / 1:20.32 / Fn3 scale Garden Railway from its inception to the present day.
NEW (October 2025)
The Fruit Special Train (featuring containerisation)
When I became interested in building my own garden railway I spent a considerable amount of time (and money) on books, videos, DVDs and scouring the internet for information, ideas and inspiration. When I eventually started construction, I used some of the ideas I had discovered, but also experimented with my own approaches. This blog outlines how I have gone about constructing my own garden railway. My aim is to provide the sort of information I was looking for when I was getting started, and also to share what I've learned (or 'borrowed' from others). I've tried to include a few 'How I ........' postings interspersed with occasional 'Progress Reports'. I do not profess to be any kind of expert - what I offer here is an opportunity for you to metaphorically look over my shoulder to see how I have gone (and am going) about this fascinating hobby.
As this is a blog, the various posts are presented in reverse chronological order (ie the most recent first). To see a categorised list of contents, go to the Blog Contents Page.
If you are thinking about building your own garden railway, then why not join the 16mm Association or the G Scale Society - you'll get plenty more advice and opportunities to visit other peoples' garden railways. Alternatively, browse through theG Scale Central website - there's plenty more guidance here and an opportunity to sound out the views of others through the G Scale Central discussion forum or the GardenRails.org forum
The Blog
The advantages of blogging are that it is immediate and uncomplicated when creating and uploading information. The other, of course, is that with Blogger it is free. The major disadvantage is that I have minimal control over how the postings are presented. The blogging system adds the most recent information to the start of the blog, hence the postings appear in reverse chronological order (most recent first, oldest last). Whilst there is a list of postings on the right-hand side, it's not particularly easy to see what is there. This introduction is an attempt to provide you with a contents list of the postings organised into categories so, hopefully, you see if what you are looking for is presented in this blog. To ensure that it always appears at the start of the blog, I update its content and set its presentation date into the future each time I add a new posting.
Recently, I needed to reprogram a Micron MR603 receiver so it could be used to trigger all the sound effects on a Micron Mini Sound module (MSND01). As this module uses the same firmware as MyLocoSoundmodules, this reprogramming would also be appropriate for these.
The sound module has seven functions triggered by inputs on seven pads (or screw terminals):
.... which has two two-way switches and two push-buttons for triggering outputs from the receiver, ....
S1 A - sends Channel 3 high
S1 B - sends Channel 3 low
S2 - sends Channel 4 low
S3 C - sends Channel 7 high
S4 D - sends Channel 7 low
Bind button - sends Channel 5 low
.... thus allowing all six of the additional sounds on the Micron or MyLocoSound modules to be triggered.
The Micron MR603 has ten output pads which, as delivered, provide the following outputs:
P1 - Front light / LED2
P2 - Rear light
P3 - 0v - 3.3v when Channel 3 is low
P4 - 0v - 3.3v when Channel 3 is high
P5 - 0v - 3.3v when Channel 5 is low
P6 - 3.3v - 0v when Channel 5 is low
A - Front light
B - Rear light
C - 0v - 3.3v when Channel 5 is low
D - 0v - Toggle 3.3v/0v when Channel 5 is low
The Micron Mini sound card inputs (and the MyLocoSound inputs) are trigged when they are connected to 0v and so, to make use of all the features, I needed to change some of the outputs from the pads to give 0v when the channels used by the buttons and switches on the Tx22X went high or low.
So, I decided to reprogram the receiver's output pads as follows:
P1 - Unchanged (i.e. Front light)
P2 - Unchanged (i.e. Rear light - not used)
P3 - 0v when Channel 3 is low (i.e. when S1 A is clicked on the Tx)
P4 - 0v when Channel 3 is high (i.e. when S1 B is clicked on the Tx)
P5 - 0v when Channel 4 is low (i.e. when S2 on the Tx is pressed)
P6 - Unchanged (i.e. 0v when Channel 5 is low (i.e. the bind button is pressed on the Tx))
A - Unchanged (i.e. Front light - not used)
B - Unchanged (i.e. Rear light - not used)
C - 0v when Channel 7 is low (i.e. when S3 C is clicked on the Tx)
D - 0v when Channel 7 is high (i.e. when S3 D is clicked on the Tx)
This is probably the part of the process which most people find confusing, so I will try to describe how it works as clearly as I can.
Let's take the changes needed for P3 as an example. The pad needs to be reprogrammed so that it provides a 0v output when the receiver detects that Channel 3 has gone low.
So, working our way across the section of the table shown above:
The first value we need to note down is 3 which tells the receiver we want to reprogram an on/off feature
Moving to the next column, we need to tell the receiver we want to reprogram pad 3. So 3 is our next value to be noted.
Moving to the third column, we want the output from the pad to be momentary - i.e. we only want the output to happen while the button or switch on the transmitters is being pressed or clicked. As soon as the button is released the output from the pad will revert to whatever it was doing when the receiver was switched on. So, our next value is 1.
The fourth column, specifies the Channel we will be using. In this case it is Channel 3 and so 3 is the next value to be noted.
The final column specifies what sort of output we want dependent on the state of the selected Channel. We want the output to start high (on) but switch to low (off) when the Channel goes low. So, we want this value to be 4 (i.e. When Channel 3 goes low, turn off the pad (i.e. it has 0v output))
So, the reprogramming code we need for this change is - 3, 3, 1, 3, 4
Let's skip to the last output in our list, Pad D. This needs to provide a 0v output when Channel 7 goes high.
Again, our first value is 3, indicating we want to reprogram an on/off setting
This time we want to reprogram Pad D - so we note down our next value as 10
Again, we want the output to be momentary, and so our third value is 1
We are using Channel 7, so our next value will be 7
And finally, as we want a 0v output when Channel 7 goes high, the value we need is 6
The coding for this change is therefore: 3, 10, 1, 7, 6
So, on this basis, the codes needed for each of the pads which need to be reprogrammed are:
P3 - 3, 3, 1, 3, 4 (for 0v when Channel 3 is low)
P4 - 3, 4, 1, 3, 6 (for 0v when Channel 3 is high)
P5 - 3, 5, 1, 4, 4 (for 0v when Channel 4 is low)
C - 3, 9, 1, 7, 4 (for 0v when Channel 7 is low)
D - 3, 10, 1, 7, 6 (for 0v when Channel 7 is high)
Putting the receiver into programming mode
To actually make these changes, we firstly need to make sure the MR603 receiver has been bound to a transmitter which has a reversing switch (i.e. which can give a high and low output on Channel 3). In the Micron range, this would include:
To put the receiver into reprogramming mode, the transmitter and receiver must be switched on. After a few seconds, the morse code for SOS (dot, dot, dot, dash, dash, dash, dot, dot, dot) has to be tapped out on the bind button. The dots must be less than a second in duration and the dashes more than a second but less than five seconds. The pauses between dots and dashes must be less than 5 seconds.
When the receiver has entered programming mode, its LED will flash once every second (referred to as 1-flash)
Reprogramming
We can now start the reprogramming process.
Taking our first set of values needed to reprogram Pad 3 (i.e. 3, 3, 1, 3, 4), we need to change that initial 1-flash to a 3-flash (i.e. three one second flashes, followed by a pause). To increment the number of flashes, the reversing switch on the transmitter need to be moved to the "reverse" or "down" position and then returned to the mid-position. Clicking it once will increase the flash-count by one. Clicking it again will increase the flash-count by another one. Thus, the LED should now be flashing three times before a pause. This is the value we need for the first code in our list (i.e. telling the receiver that we want to reprogram an on/off setting). To tell the receiver to "accept" that value, we move the reversing switch to "forward" or "up".
The LED will now start flashing once per second. We need to it flash three times, so we increment the number of flashes twice (by clicking the reverse switch twice in the "reverse" or "down" direction). Once it has reached 3-flash (three flashes then pausing), we "accept" this by clicking the reverse switch "forward" or "up". This tells the receiver we want to reprogram Pad 3.
LED should now flash 1-flash again (because Pad 3 is already set for momentary on/off). So we just click the reverse switch forward or up to accept this value.
The LED should now start flashing 3-flash, as P3 is already set to respond to Channel 3. So click the reverse switch to forward or up to accept this.
Finally, the LED should now start flashing 1-flash as the default for P3 is to give a 3.3v output (i.e. go high) when Channel 3 goes low. We need to change this to start high and go low when Ch3 goes low, so we need to change this value to 4-flash by incrementing the flashes by three reverse or down clicks and then accepting the 4-flash by clicking forward or up.
If you accidentally increment the number of flashes by too many, then keep incrementing until the LED reverts to 1-flash, then increment to the desired value.
After entering the final value in our list, the LED should stop flashing and revert to solidly on.
To program another pad, we need to re-enter programming mode with the SOS morse code sequence on the bind button.
All that might sound a bit daunting but, once you've done it a couple of times, it is really easy - albeit slightly tedious.
Here's proof that all that effort is worthwhile.
Deltang or RC Trains transmitters
Deltang or RC Trains receivers with reversing switches can also be used to reprogram Micron receivers provided they will bind with the receiver. Some of the very early Deltang receivers are unable to bind with Micron receivers and will need their transmitter boards replacing to enable them to do so. This is a job which can be done by Andy at Micronor by Phil at RC Trains. Alternative, if you are handy with a soldering-iron, it is a relatively straightforward job you can do yourself, once you have purchased the Micron transmitter module.
I was asked if I could convert a couple of Bachmann Big Hauler 4-6-0 locos to battery power and radio control using Micron radio control equipment. I hadn't realised, until they arrived, that there are at least six different "Generations" of this popular model - see https://www.girr.org/girr/tips/tips1/big_hauler_tips.html . It turned out that the two models I had been sent were Generation 2 (an Atchison, Topeka & Santa Fe loco) ......
and a Generation 4 (White Pass) version:
Externally, apart from the colour schemes, there isn't a great deal of difference between them, though the quality of the fittings and the plastic used in the Gen 2 loco as not as good as in the later Gen 4 model. The main difference between them is internal. Over the years, it seems that Bachmann developed at least six different mechanisms for the loco - as will become evident during the dismantle and conversion processes below.
Dismantling Loco
Fortunately, Bachmann have made dismantling fairly straightforward on these locos. The first job was to remove the baseplate holding the driving wheels in place. The three screws are fairly obvious....
A fourth, longer screw, is between the cylinders. This holds the cylinders in place as well as the baseplate.
With all four screws removed ......
.... the baseplate could be taken off to reveal the mechanism. Here is the Gen 2 version which, as you can see, is a series of spur gears driven by a crown and pinion on the motor shaft. This mechanism is very noisy when being run, especially at high speed.
The Gen 4 mechanism, is much simpler. A straightforward worm and wormwheel.
As we would no longer need to pick up power from the rails, I snipped off the leads from the pilot bogie at this stage. The next job was to detach the connecting rods from the centre wheels. Plastic plugs hold these in place. They were carefully prised off. I used a pair of snips to very gently lever them upwards before using a pair of needle nosed pliers to finish their extraction.
The cylinders could now be removed.
At this stage, the wheels can be removed. As you will see, I did this on one loco, but left that until a later stage with the other loco. The wheels are mounted in slots on the chassis and simply lift out.
Also, the pilot bogie can be removed at this stage by undoing the screw in top of the pillar on which it pivots. Alternatively, it can be left in place.
To remove the body from the chassis, six screws were then removed - two beside the footplate at the rear of the loco body ......
.... and four towards the front, behind the low slung air tanks either side of the boiler.
The two metal stays at the front of the loco .....
...... were then pulled out from above the cow-catcher (they are a push-fit).
The main body could now be removed.
As I was going to completely rewire the loco, I snipped off the two wires feeding the smoke unit and the headlamp at this stage.
The screws holding the iron weight in place were removed
Note a slight difference in the way the weights were mounted in the two locos.
With the Gen 4 loco, I decided to remove the motor and its mechanism as a unit. This was held in place by a steel rod passing through the sides of the chassis.
It was pushed through using a nail and some gentle tapping with a small hammer.
With the Gen 2 loco, I left the gears in place and just removed the motor, by undoing a couple of screws.
The copper pick-up strips were soldered directly to the motor contacts and so these, plus the wiring, were removed with a soldering iron.
The pick-ups on the Gen 4 loco were slightly more sophisticated plunger-style fittings. The two tiny screws holding each fitting in place were removed and the fittings taken off.
The two screws holding the circuit board in the loco cab were unscrewed ......
... the unit was removed, snipping off the associated wiring.
Rewiring the loco
I decided to start at the front and work my way back. The smokebox door assembly was unclipped .....
.... and the wiring on the back of the smoke unit switch removed with a soldering iron.
The headlamp was unclipped ......
..... and the filament bulb removed.
A 3mm warm white LED was put in its place - one leg was insulated and the other left bare, so the leads would fit into the tube which held the lamp in place.
The LED was bent to face forward before the lamp housing was put over it.
Ribbon cable ........
..... was soldered to the positive and negative contacts for the smoke unit
switch and for the positive lead of the LED - the negative being shared
with the smoke unit.
A 4-pin JST socket was attached to the other end of the ribbon cable (a 3-pin would have sufficed, but I didn't have one to spare).
More ribbon cable was connected to a 4-pin plug with an extra three cables (one for the chuff cam and two for the motor) leading to the rear of the loco (the negative input for the chuff cam was taken from the feed for the smoke unit).
The negative feed and return wires were soldered to the chuff cam contacts, ......
..... and the other two wires to the motor terminals, .......
..... before the motor was screwed .......
..... or pinned back into place.
The circuit board at the back of the cab was dismantled ......
..... and a piece of Vero stripboard, cut and drilled to the same dimensions, ......
..... before being bolted to the bracket.
The ribbon cable was then soldered to the Veroboard strips ......
..... and an 8-pin JST socket soldered on (a 6-pin socket would have sufficed)
The bracket was then screwed back into place at the rear of the chassis.
A slot needed to be cut into the back of the cab body to give clearance for the plug. I used a slitting disk in a mini-drill for this.
The loco body and wheels could now be reassembled.
The tender - dismantling
Four screws hold the tender body to its chassis. They are readily apparent when the tender is turned upside down. These were removed .......
.... and the body simply lifted off.
I decided to leave the speaker in place, but the soundboard was unscrewed and its mounting pillars taken off with a razor saw.
The contacts for the battery .......
..... were slid out, ......
.... and the mouldings ........
.... removed with a razor saw.
The chuff-cam lead from the sound card was snipped off and removed.
A mounting bracket for the switch and charge sockets was designed using Tinkercad and 3D printed (the .stl file for this is available as a free download on the gardenrails.org forum.
A 4-pin JST plug was soldered to another piece of Vero stripboard .....
... and a 3-position SPDT switch and a DC charge socket acquired.
The switch .......
.... and the DC socket were wired-up ........
.... before being inserted, along with the 4-pin JST plug, into the mounting bracket.
The lead from one pin of the switch was then soldered to the positive terminal of the DC socket.
The Micron MR603c receiver/controller was wired-up - with leads connected to the positive and negative input pads, the motor pads and the C, D, P1, P2, P3, P4, P5 and P6 pads. P1 and P2 are for the headlamp and the tail lamp (for future attachment) and pads C, D, P3, P4, P5 and P6 are for the triggers for the sound card.
The trigger wires were then soldered to the trigger inputs on the Micron Mini Sound Module, together with shared positive, negative and motor power leads (see circuit diagram below for more detail).
The mounting bracket was then screwed to the tender chassis, being carefully positioned so the switch and sockets would be directly below the flap previously used as the opening for the 9v battery compartment.
It was screwed rather than glued in case any additional adjustments were required at a later date.
A battery pack was made up from three 18650 li-ion cells, connected to a 3S BMS (Battery Management System) board and to the balance charge socket (see circuit diagram below). NOTE: Care must be taken when connecting the cells together to prevent accidental short circuits. Li-ion cells are extremely volatile and should be handled with caution. The battery pack was held in place with a couple of cable ties passed through holes drilled in the floor of the tender.
An 8-way JST plug was wired up to the postive, negative, motor power, chuff cam input to the sound module, and to the headlamp output from the MR603c (with a 150R resistor connected in series) (see circuit diagram below), with the wires passing through holes in the front of the tender and the floor
Once the connections had been made, the last few centimetres of the cables were shrouded in black heatshrink wrap.
NOTE:
Initially, I passed the cable linking the tender to the main loco,
through the original hole in the front of the tender, however, because
the cable is thicker it sometimes pulled the loco or tender off the
rails, and so I made a new hole in the centre of the tender's buffer
beam, which works more reliably.
Circuit diagram
Click to enlarge
Reprogramming the MR603 receiver/controller
The owner of the locos had also purchased a Tx22X transmitter from Micron, which provides a series of outputs using two-way switches and push buttons.
Making the most of these outputs, I needed to repogram the receiver so it would trigger the soundcard as follows:
S1 - A - "All Aboard"
S1 - B - Bell
S2 - Safety valve
S3 - C - Coal shovelling / Injector
S3 - D - Water pump
Bind button - Whistle
This would entail changing the default outputs from the receiver pads:
It seems that, as supplied, the bogies have a tendency to derail. In addition, on the White Pass loco, I replaced the original spring with a stronger one - made by wrapping phosphor bronze wire around a piece of brass bar of the right diameter.
I also noticed that some of the brake blocks were missing from both locos, so I designed some replacements in Tinkercad and 3D printed them (Files available as free downloads from the gardenrails.org forum).
The locos were then given a few test runs
Conclusion
On paper, the conversion of a Bachmann Big Hauler ten wheeler is relatively straightforward. However, the differences in the design of the mechanisms add some complications. In addition, the need to transfer connections from the tender to the main loco adds another level of complication. This could be reduced if the smoke generator and chuff cam aren't used.
Overall, the models are quite easy to dismantle when compared to some other G Scale locomotives and there is plenty of space in the tender to hide the batteries and control equipment. Those who are wary of lithium batteries may prefer to use the space for a NiMh battery pack.
Introduction
