How I used Audacity to create sound files for my Ford(ish) railbus

Introduction

Having just modified a cheap USB MP3 Player to enable a Deltang receiver to trigger movement from file to file (see How I modified an MP3 Player to provide sound for my railbus), I needed to create some appropriate sound files to use with it.

I decided that I needed five sound files:

1. 20 min of silence (when the railbus was stationary with no engine running)
2. Engine start-up and idle (for 20 minutes)
3. Horn, gears and acceleration through the gears before running sound (for 20 mins)
4. Deceleration, brake squeal and idle (for 20 mins)
5. Engine stop

I figured that I could move forward and back through these files using the direction switch on my Deltang Tx22 transmitter to cover all eventualities under which the railbus might operate.

Locating suitable sound files

The internet is a wonderful place. I searched for appropriate sound files of antiquated Ford motor vehicles which I could use. Initially, I searched for Model T Ford sounds as I had previously used some of these to dub sounds on to a video of the railbus in action (see A Day in the Life of Peckforton Station).

 These sounds had been suitable for lineside shots, with the railbus moving towards and away from the camera, but I needed engine sounds which were more constant.

Eventually, I managed to track down the sound of a Model A Ford on the StockMusic.com website. For a modest sum (just under $10), I was equipped with the sound of a car running past, the car starting, idling and stopping, and the sound of a car horn.

I was now ready to start editing in Audacity, which is a free open-source sound editing program available from SourceForge. To demonstrate the editing processes involved in producing the sound files, I'll show you how I produced the most complicated one - the third file with the horn, gear change and acceleration to running speed.

The first step was to start up Audacity and then open the downloaded file containing the idling engine sound. The engine start and engine stop sections of the file were highlighted and then deleted, leaving just the sound of the idling engine.

Part of the engine sound was highlighted and then Adjustable fade ... was selected from the Effects menu

 The opening volume was set to 100% and the closing volume was set to 200%. You may need to experiment with these values to suit the sound file you are working with.

 Once the rising effect of the volume was checked, the same section was highlighted once more and the Sliding Time Scale/Pitch Shift tool was selected from the Effects menu.

 The initial tempo change was set to 0 and the final tempo change was set to 200%. Again this final value was determined by experimentation. After some checking I decided the pitch needed to be changed as well to give a rising pitch to the engine as it increased in speed. The final pitch shift was set to 100%.

 The effect was tested to check the settings sounded satisfactory.

 The edited section of sound was highlighted, copied and pasted into the sound track and another section of the original idling sound was edited to give a slightly different and shorter section of rising sound, which was copied and pasted again to give the effect of working through four gears.

I decided the sound would be enhanced with the addition of the gearbox whining in the background. I tracked down the video of a vintage bus on the internet and extracted the sound using another piece of free software - Any Video Converter.

Once a suitable section of whining gearbox was found it was imported into the Audacity .......

.... where it opened as a new track

The short section of whine was copied and pasted a few times....

 The section of whine sound before the rising engine sound was highlighted and then, using the Amplify tool from the Effects menu, its volume was reduced to zero (there would be no gearbox whine while the railbus is stationary).

A section about twice as long as the rising engine sound was highlighted and amplified, rising from 0 to 400% using the Adjustable fade tool from the Effects menu (again some experimentation was necessary to find the most appropriate value).

The tempo and pitch of the same section was edited with the Sliding Time Scale/Pitch Shift tool from the Effects menu. The tempo was changed from 0 to 200, and the pitch from 0 to 100%.

The effect was applied again and copied and pasted to match the other sections of the engine sound track.

After some tweaking and adjustment, the sound of a grating gearbox (found on a free sound effects website - https://www.freesound.org/ ) was then imported and copied and pasted on to a new track to occur at appropriate places alongside the engine and gearbox sounds.

Finally, the sound of the Ford's klaxon horn was imported and added on a track near the start of the recording.

 A similar approach was used to create the other files needed (ie start and idle, decelerate and idle, idle and engine stop). These were exported from Audacity as MP3s and then transferred, one at a time (to ensure they appeared in the correct order) on to the micro SD card.

The SD card was then installed into the MP3 player on the railbus and tested to ensure everything worked as intended.

As you can see, there is a 1 second pause when moving from one track to another. I may look into the possibility of using a recordable sound module triggered by a Picaxe chip to mask this pause, but for now I am happy to live with the pause - my imagination disguises the gap in sound and when making videos of the railbus, I can edit out the pauses.

How added suspension to my railmotor

A couple of years ago, I constructed a two-car railmotor based on a couple of Andel resin freelance coaches (see How I constructed a railmotor). Since her construction, she has been through quite a few reincarnations as I have sorted-out a series of problems. Whilst this has at times been frustrating, the solutions have also provided me with opportunities to develop knowledge and experience in a range of different fields.

Problem: Erratic radio control

Initially, she was controlled with a keyfob controller using a circuit from a gadget for dimming LEDs.

Solution: After trying various modifications, I eventually discarded this control system and installed a Deltang receiver/controller (see An evaluation of the Deltang r/c system)


Problem: Lack of power
 Initially, the railmotor was powered by an IP Engineering motor and gearbox assembly. The 16:1 gearing on this mechanism meant that there was insufficient power from the motor running on 12 volts to take the power car and trailer up the 1:40 gradients on the railway.
Solution: The original motor/gearbox was discarded an MFA gearbox motor was mounted beneath the chassis powering the wheels through bevel gears. (see  Progress Report 48)

Problem: Regular derailment
Whilst sometimes she would run round the track without problems, on other occasions she would regularly become derailed as she negotiated some pointwork.
Solution 1: My first diagnosis was that she needed more weight over the front wheels - to keep her nose down. Some strips of lead flashing were trimmed to fit into the cavity beneath the bonnet and, with fingers crossed, I gave her a trial.

Some sets of points she negotiated without problem, but others she refused to take without derailment. Close scrutiny of her progress showed that one wheel was riding up over the check rail, thereby causing the other to foul the frog.

 Solution 2: My next attempt was to widen and deepen the flanges of the Tenmille wheels with plasticard as I had done successfully with other finer-flanged wheels (see How I improved the compatability of IP Engineering wheels with LGB pointwork)

Tenmille wheels

Plasticard 'washers' roughly shaped

Superglued to the back of the wheels before being filed to shape

Testing.

 Whilst this has been successful with other rolling stock, this was not so with the railbus. I then tried some LGB spoked metal wheels which have wider treads and deeper flanges and of course are designed to be compatible with LGB pointwork. No success. Clearly the problem was more deep-rooted.

I studied her closely again as she went through the points and realised that, as her wheelbase is quite long (in comparison to most of my other locos), she was unable to flex her chassis if the rail dropped slightly. This meant that in certain places, not all four wheels were in contact with the rail. Whilst this was less of a problem on straight track, it was disastrous on the curves of points which were not perfectly level.

Solution 3: What was needed was some simple form of compensated suspension - to allow the leading wheels to follow the contours of my uneven trackwork. After considering (and rejecting) a range of complex hinged systems, I eventually opted for the simplest - a U-bracket which was loosely mounted so it could rock from side to side.

 A bracket was made from 64thou brass strip, with two fixing-holes along the centre-line.

Between these holes a short length of 2mm diameter brass rod was soldered.

The bracket was then bent into shape and fixed in place with self-tapping screws as, unlike nuts and bolts, these could be screwed-in without me having to dismantle the bonnet assembly (a fiddly process).

Another test-run showed that this solution was successful. The wheels now remained in contact with even my most irregular trackwork.

A few more test-runs showed I needed to adjust the back-to-back distances on the wheels on the powered axle, but the railmotor will now trundle around the railway at a sedate pace with only the occasional mishap - usually explained by overhanging vegetation or twigs which have fallen on to the track.

I spruced her up by giving the radiators and headlamp surrounds a couple of coats of brass paint and painted the underframes and steps with matt black.

And then, of course, she needed extensive test-running ......

And then, although she will never need to traverse R1 pointwork (the only R1 points I now have on my railway are in the copper mine sidings), I decided to see how she would fare through the most challenging trackwork on my railway.

No trickery involved (apart from editing out the manual changing of the points) - I even tried her flat-out through the points without mishap. However, she struggled to get through two R1 points connected in tandem to form a cross-over. But this was because the buffers between the two cars locked rather than any problem with the suspension system.

So, I feel very pleased with my applied problem-solving in this instance. This is one of the reasons I find railway modelling so rewarding - each day presents a new challenge which requires ingenuity and sometimes dogged persistence to overcome.

Progress Report 48

The weather has been quite mixed since the previous Progress Report (see Progress Report 47) but I have managed to get a couple of complete operating sessions in, and also have run the railway in tail-chasing mode a few times when we've had visitors or when I just fancy seeing something running.

Battery Power

I must admit, I am becoming more and more enamoured with battery power. Today, for example, one of my friends phoned up and asked if he could bring his future son-in-law round to see the railway in half an hour's time. It's been a week or so since I last ran a train as the weather has not been conducive and normally I'd say, give me an hour and a half to make sure the track is clean enough - but not this time. A quick whiz round the track to remove fallen leaves,

........ a battery loco was placed on the track with some rolling stock and within twenty minutes we were up and running.

Normally, after cleaning the track, I'd have a test loco running around a couple of times to check whether there were any mucky bits I'd missed, but now I have the confidence to run a full train straight off.

I'm looking forward to extending the number of battery powered locos so I will eventually have a full complement for a running session (a minimum of three locos - one passenger, one goods and one for the copper ore trains).

Deltang radio control system

After hearing about this system on the G Scale Central forum, I decided to invest in a transmitter and a couple of receivers to see whether it would be up to running my slowly expanding fleet of battery operated locos. The Deltang system uses 2.4gHz with a transmitter which can control up to 12 locomotives independently. (see An evaluation of the Deltang r/c system). After some initial trials with one loco, I have now invested in another three receivers and so have no excuse not to finish adapting and building sufficient battery locos to run a full operating session.

The most reliable battery loco so far is the 0-6-2 model based on the Southwold Railway's No.4 Wenhaston (see How I constructed a battery powered 0-6-2T locomotive). I have now run this extensively with a Deltang receiver/controller which, despite its diminutive size, seems to be able to cope with the loco hauling a full train up the line's gradients. I am intending to add a heat sink to the receiver just to be on the safe side, but I'm not entirely convinced it's needed.

IP Engineering Lollypop railcar

To test out the Deltang system on a low powered loco (all my other battery models run on 12 volts), I am in the process of putting together an IP Engineering Lollypop railcar kit (no longer available) which I've had on the to-do shelf for well over a year. This is powered by 4.5 volts and responds well to the Deltang controller/receiver. Although she's sufficiently functional to enable me to engage in testing ........

... she still requires detailing, painting and weathering. I'm considering making a small flat truck to go with her so that she will form the railway's engineering train. (see How I constructed an IP Engineering Lollypop Railcar)

New gearboxes for the IP Engineering diesel and the railbus

 Diesel loco

The IP Engineering diesel was already on its second gearbox when I constructed it. I'd bought it as a half-made kit and it came with a stripped gearbox and an new one. Within a very short space of the time the plastic gears in the new gearbox became stripped as well.

I tried constructing my own using a metal worm and worm wheel from Cambrian Models but my engineering skills were not sufficient to make a gearbox which would mesh properly. A friend came to the rescue and constructed one for me using metal 00 loco gears. However, he was not convinced the gears would be up to the job for more than a short period of time.

When testing this model with the Deltang controller (see above), I found that while it was fine running in reverse, the controller sometimes struggled to turn over the motor when it ran forwards. After consulting the designer of the Deltang system, he adapted one of his ordinary receivers to work with his Tx22 transmitter enable me to use the Brian Jones Mac 5 controller with the transmitter. She now works reliably though she is more responsive in reverse than when travelling forwards which suggests the problem lies with the mechanism rather than the control system.

If the present gearbox does succumb to excessive wear, I will replace this gearbox with an MFA Como gearbox motor and bevel gears, as I have done on the railbus (see below)

 The Railmotor

The railmotor also had a gearbox with plastic gears and while the gears had not become stripped they were wearing alarmingly. A major problem with the motor and gearbox on this model was that it was seriously under-powered. The gearbox provided only 16:1 reduction and as a consequence the motor didn't generate sufficient torque to power the railbus when pulling its trailer car.

I trawled the internet for suitable gears and motors and it looked as if I would have to have a special gearbox constructed for me (at considerable expense!). After consulting the opinions of fellow modellers on the G Scale Central forum, I invested in a 30:1 12-24v gearbox motor and a set of bevel gears from MFA Como. I have since seen these available in my local Maplin store - and what is more the gearbox motors cost only around £10!

After making a simple brass U-shaped bracket for the wheels I needed also to source a sleeve which would slip over the drive axle to increase its diameter to 4mm for the bevel gear. This I tracked down from MotionCo, and when it arrived, I realised I already had some 3mm brass tube which would have sufficed. This is all part of the learning process!

It's a whole lot easier to mesh bevel gears than it is to mesh worm gears and within a short space of time I had a fully functioning and powerful railbus. So far, I have only been able to test it with a few alkaline batteries, but I have just taken delivery of a 12v li-ion battery and will shortly have another couple of Deltang receivers so I will be able to wire this up properly and enable it to enter service (see How I built a railmotor and scroll down to the update).

At last figured out where the water goes

Ever since I installed the stream (see How I constructed a stream) I have been perplexed as to why it sometimes will run for several hours with only minimal topping-up and yet on other occasions it needs topping up every half an hour or so. There seemed to be no logical reason until, recently, I had need to clean out the sump hurriedly before a visitor came to call to see the railway and more specifically how I'd constructed the stream. Whereas prior to the clean-up I'd been topping it up every half hour, while he was there (for three hours) it didn't need a top-up once. Suddenly it came to me. If the holes were blocked in the cover over the sump, rather than flowing down into the sump, the water would soak away around the edge of it.

So now, from time to time, I poke a pointed stick down into the holes drilled in the lid of the sump (an inverted plastic dustbin lid) to unclog them and, at last, the stream goes on happily for hours without the need for topping-up.

Progress Report 47

An almost unbroken spell of sunshine for around three weeks has led to quite a few running sessions and more than a few spells of continuous running while we've had barbecues or simply lazed in the garden. However, I have also taken the opportunity to finish off a couple of jobs and spend some time trying to sort out others.

Loco No. 4 Bulkeley

As mentioned in Progress Report 46, I have been working steadily on scratchbuilding a body for loco No. 4 - Bulkeley, based loosely on the Southwold Railway No. 4, Wenhaston. This was my first venture into building a steam outline loco but I used the skills I had acquired in building the Fowler diesel and rolling stock such the the cattle wagons to construct her largely from plasticard (see How I constructed an 0-6-2T Manning Wardle locomotive). The build was fairly straightforward though I did run into an unforeseen problem when she developed wheelspin on what seemed like insignificant gradients. I eventually tracked this down to the lower end of the bracket supporting the valve gear which was rubbing on the track. This was solved through the addition of an upper support bracket.

For a while, I was uncertain as to the livery of the original Southwold Railway loco - there seemed to be some ambiguity in the books on the SR which suggested she was lined out in light and dark green and yet the photos of the loco I had unearthed show no evidence of lining. After making an enquiry with the Southwold Railway Trust, I discovered that when delivered from Manning Wardle, she was lined.................

....... but when she entered service she was painted in plain dark green livery which she retained throughout her working life. However, towards the end of her life, her livery faded and her works livery started showing through.

My model has now entered service on the Peckforton Light Railway and for the moment she is sporting the line's livery of Brunswick Green (or in her case, Rover Brooklands Green from a Halford's rattle can aerosol). I am trying to decide whether to line her out in gold as with the line's other locos or whether to leave her unlined as a homage to her Southwold origins. You'll notice that I've positioned the loco's number beneath the nameplate as in her Southwold days.

She also has acquired a bespoke driver, made from oven hardening clay. I wanted to represent a driver or fireman passing over a token or just leaning out to watch the loco's motion. He's reasonably detailed though it looks as if his face has met with an unfortunate collision somewhere down the line.

The loco was my first real venture into battery power and after a few teething troubles I am steadily being won over to this form of power. However, I am also upgrading my DCC powered fleet (see below) to improve their reliability.

Adding DIY Power buffers to DCC locos

As all my track-powered DCC locos are designed around LGB 0-4-0 motor blocks it's inevitable that they experience problems when running slowly over the plastic frogs of pointwork. Last year, I invested in a Massoth Power buffer and added this to one of the locos to evaluate its effectiveness (see Progress Report 37). I was extremely pleased with the outcome and vowed I would equip all my locos with one. Despite its relatively low cost (under £25), having retired, funds are not always readily available and so when I came across an article in the French railway modelling magazine, Voie Libre, explaining how a modeller had added his own power buffers to his 0n30 locos, I researched the subject and found out how it can be achieved for as little as £2.50 per loco (see How I added DIY Power Buffers to my Locos).

 All my track powered locos are now equipped with power-buffers and, because I was hard-pressed to find a suitable location for the buffer in my Fowler diesel, I adopted the technique used in the original article and added the capacitor to the footplate to represent an air cylinder.

Working on the gearbox of the IP Engineering diesel loco

 I spent a day or so trying to build my own gearbox to replace the one supplied with the IP Engineering diesel kit, Jessie (see How I constructed a battery powered diesel from a kit). The gearbox as supplied used plastic gears and after only a very brief period of test running these became stripped of their teeth. I bought what I am hoping are more substantial metal gears from Cambrian Models but found that their 20:1 gears are not a direct replacement as the overall dimensions differ. I therefore attempted to construct my own gear housing from brass.

Whilst this worked to some extent, I found that as soon as even a small load was placed on the loco, the gears slipped (though only in reverse, the mesh was fine as long as the loco only travelled forwards). I am now attempting to construct a more reliable gearbox, building on the knowledge I've acquired so far and drawing on the expertise of a friend who has more metal working experience.

Improving the keyfob control on the railbus

After some interesting discussions on the G Scale Central forum about the merits of using a cheap 12v LCD dimmer unit to control a motor.

 

It seems that the unreliability which I had encountered over the speed control of the motor could be greatly improved through the simple addition of a diode across the output connections - see the excellent online article by Dave Bodnar.

I have disassembled my railbus (see How I constructed a railbus) and have duly wired in the requisite diode.

 At the same time I decided to replace the array of AA battery boxes I had used previously with a single 12v Li-ion battery pack which would take up considerably less room. Unfortunately, the pack which I had bought from China via a well known online auction site ceased to function and so I have been unable to test my newly adapted control board. Furthermore, I am growing increasingly concerned with the IP Engineering gearbox which at 16:1 does not provide sufficient torque to power both cars and I am assuming will ultimately strip its gears (see above). I am therefore investigating an alternative approach to powering this vehicle and will post an update when I feel I have made some progress.

More running sessions

 As indicated above, the weather has provided me with plenty of opportunity to run trains. I have continued to use my original freight handling computer program (see Computerised freight operation)  but have discovered that the freebie software I used to create the freight handling program will not work on Windows 7. I have fortunately found another programming environment which is not only free, it will create standalone programs to run on PC, Mac, tablets and smartphones (Livecode - which is based on the original Mac program - Hypercard). Once I have completed the re-programming I am hoping to be able to distribute various versions for others to use.

In the meantime, here is a small taste of some of the moments drawn from recent operating sessions.

The Down mid morning passenger approaching Bickerton

No. 2 Beeston on the afternoon Up passenger crosses the River Gowy between Peckforton and Beeston Castle

The daily pickup goods arrives at Bickerton with Hunslet No. 3 Bickerton

The pickup goods departs Bickerton on its way up the line towards Bulkeley

Shunting at Bulkeley

No. 3 emerges from the Copper Mine branch running light after delivering a fuel tank wagon

The Up pick-up goods approaching Peckforton where it will cross the Down afternoon passenger

 Now I have managed to sort out the slow running of the locos (see above), I take great delight in relaxing from time to time in a strategically placed garden chair as I watch each train slowly threading its way through the undergrowth from station to station. There is something very satisfying about seeing a train which I have created going about its business.