G3 Forum

Diesels, Electrics & All Things "Modern Image" => Locomotives (diesel & electric) => Topic started by: Doddy on Mar 02 2018 10:42

Title: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Mar 02 2018 10:42
Plans are afoot!

The RS540 specification brushless motor and the Quanum 2208 Brushless Motor have arrived from China and the UK. The RS540 has FET (Field Effect Transistor) feedback for connection to a an ESC (Electric Speed Controller) based Brushless Controller with FET inputs, the Quanum comes without FET's, as does most Radio Control equipment on the market.

Whilst waiting for some remaining items to be delivered, I wanted to see how they fared physically in relation to Gauge 3 back-to-back wheel dimensions, although the main plan is really to test their slow speed control potential for model railway applications before I start making any decisions on manufacturing gearboxs and mounting frames.

Here they are seen in comparison to a set of G3 wheels from GRS - Ref: Slaters Plastikard G3125 Gauge 3 (G64) Coach Wheel 3' 7" Plain Disc

Here they are with the RS540.

(http://thumb.ibb.co/geWdSc/20180302_090433.jpg) (http://ibb.co/geWdSc)

(http://thumb.ibb.co/j8wj0x/20180302_090229.jpg) (http://ibb.co/j8wj0x)

(http://thumb.ibb.co/fENrfx/20180302_090302.jpg) (http://ibb.co/fENrfx)

And with the
Quanum 2208

(http://thumb.ibb.co/kgjF7c/20180302_090628.jpg) (http://ibb.co/kgjF7c)

(http://thumb.ibb.co/hEfitH/20180302_090657.jpg) (http://ibb.co/hEfitH)

(http://thumb.ibb.co/f5phnc/20180302_090647.jpg) (http://ibb.co/f5phnc)

The Quanum 2208 was selected for its small size potential for use in very small locomotives and Electric multiple Unit rolling stock where you don't want the motors intruding through the floor. Like these Isle-of-Wight, ex-LT1938 tube vehicles which have very small diameter wheels, typically in the region of about 2' 6" . . .

(http://thumb.ibb.co/mYscnc/Class483_dinosaur.jpg) (http://ibb.co/mYscnc)

The RS540 was selected for my ADtranz 12X locomotive test rig where more power is required. This project was initially documented in this thread - http://g3forum.org.uk/index.php/topic,2087.msg13549.html#msg13549

The Brushless Motor Test Rig (barring acquiring some remaining cables) is almost complete parts wise, and nearly ready to be assembled to test various motor/controller combinations.

(http://thumb.ibb.co/j9tHnc/BLS_GZ_KLV_7_0_20140109_bobs_2.png) (http://ibb.co/j9tHnc)

This build thread will be added to with my experiences with Radio Control, Digital Sound and of course the locomotive builds - providing I can find a suitable means of propulsion.



Title: Re: Doddys HaupWerkstatte - My build thread
Post by: hornbeam on Mar 03 2018 08:55
All very interesting, and now you have got me thinking about 38 stock in our scale!
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Mar 03 2018 09:23
Quote
All very interesting, and now you have got me thinking about 38 stock in our scale!

You'll have to build it with air-operated doors (or at least simulated air operation)!
To be realistic they will have to open and shut several times before the starting signal bell will "ping".......memories of the Northern Line commute from Morden in the 1960's!

John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Mar 03 2018 10:43
It's certainly very ambitious Doddy - but why not?

It's Gauge 3 and we have a lot more room for interesting stuff on board...    :D

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Sep 02 2018 20:55
Walsall Models G3 LMS ICI Wagon

Ideal for dragging behind a Whistler... 8F, 25, 45, 46, and latterley pairs of 20s and pairs of class 37's


(https://thumb.ibb.co/bJ9Axz/20180902_110916.jpg) (https://ibb.co/bJ9Axz)

(https://thumb.ibb.co/mga0xz/20180902_110933.jpg) (https://ibb.co/mga0xz)

(https://thumb.ibb.co/dxnkVK/20180902_110922.jpg) (https://ibb.co/dxnkVK)
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: keith Bristol on Sep 04 2018 20:35
Interesting...

I saw those hoppers at Walsall... nice...
Title: Digital Sound and the Deltic
Post by: Doddy on Nov 18 2018 07:30
For most, the evocative sound of the Deltic commands attention. Up close, the throb of the engine creates reverberations in your chest. But how to record the Deltic? Unknown to many is that the source of the engines howl and beating comes from each of the two engines respective air intakes. Problem is, the exhaust is on one side of the locomotive and the air intake is on the other.

The use of close-micing and several microphones allows a multi-track synchronised recording that can be edited later.

This is myself and Kevin West being filmed, recording 55 019 whilst under static test, previous recordings were made on the steep bank of Barrow Hill including the overload shutdown whilst under acceleration which made me reminisce being back on Stevenage new town station as the 14 coach Down 'Aberdonian' pulled away north on its evenings run up to Aberdeen.

The next step is to create and edit the digitally recorded samples and load an ARM 7 processor chip with 24bit (studio quality) sound.

https://www.youtube.com/watch?v=NHKTBvr0hk8&feature=youtu.be
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Nov 18 2018 09:43
I can only once recall having experienced the sight and sound of a "Deltic" in full flight (I lived in the far South near Battle and was more accustomed to the endless rattle of the Hastings DEMUs).

Was around 1968, while sitting on New Barnet station, when I saw an UP express approaching in the distance, along the straight track, and the ground shook as it got closer.

A big contrast to the Cravens DMU which had taken me there from Kings Cross, to attend a hearing in the County Court...... it struggled to get started and limped all the way, the driver having more than once got down from his cab and hit something underneath with a spanner!

The next occasion I had cause to travel North was to Leeds but by then the HST 125s had taken over.... a shame but the restaurant car breakfast was excellent....all paid for by the firm! One thing I recall about the 125s was a dreadful smell under hard braking......must have been something to do with the composition of the brake blocks.

Regards,
John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Nov 18 2018 10:28
A big contrast to the Cravens DMU which had taken me there from Kings Cross
You can imagine how knackered I was then travelling out from and back to Stevenage every weekend by Class 105 Cravens. All stops KX to Stevenage.

And all that after visiting KX, St Pancras, and Euston stations, 3rd rail Class 501's or LT1938 stock out to Queens Park and Willesden Jnc for Willesden Electric Depot, Hymeks at Old Oak Common and back to Paddington for the evenings departures with Westerns, Hoovers and named WR Brush 4's.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Nov 18 2018 10:43
Quote
You can imagine how knackered I was then travelling out from and back to Stevenage every weekend by Class 105 Cravens. All stops KX to Stevenage.

Indeed, I had thought the Hastings units were bad enough until I had experienced the GNR suburban service!
At least the Hastings trains had a buffet car to ease the agony!

Regards,
John.
Title: Low Cost Sound
Post by: Doddy on Dec 27 2018 14:09
Following on from Tims request for low cost sound http://g3forum.org.uk/index.php/topic,1661.msg14579.html#msg14579

First of all, having a sound sub-section on this forum is likely to go the same way all other forums have gone - straight into the ground! RMWeb, ukdccsound and many others have caused endless pissing matches due to one thing.

It costs real money to do this right and people wont share the results for nothing. #metoo #nocando

Generally, there is no money being put in by the people who want the results of considerable amounts of time effort and lots of editing work, notwithstanding the politics of gaining access to locomotives and supporting that access with financial donations.

Hence the popularity of low cost sound units like mylocosound (£62) and others, compared with high cost ZIMO and LokSound DCC sound units (£187), and even more expensive MiTroniks combined power controller and Sound Units (£300+), of course G scale units like Dallee (£118) and Phoenix (£259) are primarily geared for US locomotives and not fully reprogrammable by users.

The DCC sound units from ZIMO and LokSound are fully user programmable via a USB cable or convertor box driven from a specific manufacturers PC sound programming application. But ONLY FOR YOUR OWN PROJECTS not commercially available projects! - from a sound perspective these are locked out, although access to general CV's can still be changed.

Projects like mylocosound, Dallee, Phoenix and the likes use a basic engine noise and then synthesize the engine noise to create acceleration and decceleration noises of the throttle being moved. This is synched to the output Vdc of the controller concerned and the sound follows the voltage applied to the motor.

Result - CRAP!

So, we need our own sounds, well , at least for those that tinny sounding expensive decoders are not going to pass muster, and not for those whose embarrassment at spending enormous amounts of money on low bitrate sound cards won't allow them to change their requirements. And for those whose budget is low cost - like mine these days, cheaper solutions are available if you want to put the work in.

Obtaining decent sounds are normally done by arranging personal access to specific locomotives.

This is a short list of principle sound sources -

(https://i.ibb.co/bQ0pSYP/Sound-Sources-White.png) (https://ibb.co/bQ0pSYP)

Of course you need a method of recording them . . . this was taken from an old website I had in development.

(https://i.ibb.co/s3H3tRZ/Recording-Process.png) (https://ibb.co/s3H3tRZ)

The flow from locomotive, through high quality microphones, through a high quality recording device, processed by a good audio editor, and finally loaded onto a sound chip via PC software.

50 to 100 hours work for just the editing cycle would not be uncommon.

Why high end?, well because low cost recording devices like smartphones do not record quality sound with a wide dynamic range like high end microphones.

See this view of a GWR King Class whistle, most of the background can be heard but when the whistle blows, most low cost recording devices cannot cope with the transition in volume and clip the audio.


(https://i.ibb.co/ngQpcsx/GWR-King-Whistle-GW.png) (https://ibb.co/ngQpcsx)

There is also the issue of Doppler Effect, of which sound recordings made lineside are absolutely useless for programming a soundchip.

Thesedays microphones in Sound Recording devices like GoPro are used allowing sound recordings to be made whilst the locomotive is in motion, something I had done with traditional Sennheiser microphones since 2007. See 56 003 below . . .

(https://i.ibb.co/r04p4cc/56-mic-b.jpg) (https://ibb.co/r04p4cc)

That way, locomotive recordings can be made of the locomotive under light engine and hauling railway stock, the loads, engine sounds and reaction to movement can be recorded, the sound clips edited on an audio editor and a more realistic representation of the locomotive is achieved.

John Candy asked for low cost sound card solutions, well I found this video today, https://www.youtube.com/watch?v=lv8wqnk_TsA

I have checked out the hardware and will play with it once it all arrives in the post. This baby (Adafruit Audio FX Sound Board - WAV/OGG Trigger with 16Mb Flash Memory) is about £27 on Amazon.


(https://i.ibb.co/Xj8rTYW/2220-01.jpg) (https://ibb.co/Xj8rTYW)

References:Viele Spass! Have Fun!

Bob
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Dec 27 2018 20:22
Robert,
This makes interesting reading. The pcb you show is very similar to the Explorer 64 pcb that I am about to experiment with. I plan to use it to feed GCode data files to my laser etcher. But it should be possible to pump sound files to a simple amplifier chip and then to a cone in cone isobarick speaker system

IanT knows more about this pcb than I do, at the moment! My personal sound system is a little "different" and has a headphone amplifier rated at 25w RMS  and main speakers a metre square.

It is too late in the evening for me to focus clearly but I will study this more in the morning.

Regards

Ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Dec 27 2018 21:00
I have been out for much of the day but this sound project seems to be going ahead in leaps and bounds!

My original suggestion was merely for a library of files as a guide to whistle sounds, to be used to adjust the output of sound cards of the MyLocoSound variety.
If a simple card which can accept engine sound from recordings is possible (I believe Brian Jones does sell a card which can be ordered with a limited choice of loco classes.... at a price) then that takes the game to a whole new level.

As Bob points out, the sound recordings still have to be obtained and that requires adequate equipment, skill and a willingness to obtain permissions and trudge around preservation sites.

Quote
First of all, having a sound sub-section on this forum is likely to go the same way all other forums have gone - straight into the ground! RMWeb, ukdccsound and many others have caused endless pissing matches due to one thing.

The sound files and other data can be held on the Gauge3.info server (the G3 Wiki) and will be available as long as I am around and provision will be made to ensure they survive me.

This forum will also be maintained for as long as it is serving a useful purpose.

I will follow developments with interest but will not comment on the technical aspects since I am out of touch with developments such as Arduino. I haven't written a full program since the mid-1980s when CP/M was the operating system for micro computers.

Regards,
John.

Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Dec 27 2018 23:16
I've not thought too much about 'on-board' sound effects - certainly not to the level that Doddy has..

The Adafruit board looks like an interesting (and affordable) sound option and it would be simple to control via an external micro (such as an Arduino or MM) using I/O pins instead of physical 'buttons' (as shown in the YT example). A further step in complexity would be to use something like the E64 Micromite (which Ralph has just acquired) and which has USB and SD built-in. As far as I can tell from a quick look, the sound chip plays pre-loaded (FAT) sound files and comes 'pre-programmed' with certain sequences. The E64 has a file system that can access the SD card and could (in theory) feed other devices via USB - but we are moving into real complexity here. It also has SPI available - which can be used to re-programme the sound chip - which has quite a lot of programmable options it seems... but now we are getting into very advanced territory.

I checked and the VS1000 chip appears to cost about 15 Euros (inc VAT) one-off - so the Adafruit board at £22 (with 16Mb Flash) seems very reasonable. However the option is there to do a custom PCB if ever required - working off the same code base.

There may be all sorts of problems (Gotchas) using this device in practice for some applications - like trying to play continous sound and getting pauses whilst moving between files for instance - even short blips might be a problem. Less of a problem if you need discrete sounds (like whistles etc) of course. So I guess the solution is for someone to 'suck it and see' (what is possible).

Look forward to hearing more but I'm currently still in recovery (our Grandchildren only left yesterday) and building my strength for the New Year!    :-)

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Dec 28 2018 04:21
IanT,
Making a custom PCB might be beyond the resources of a single use user. What you can get is "prototyping board" which has single plated holes which do not connect. You connect these with a conductive ink pen, so in effect you play "join the dots"... Any mistakes can be rubbed out, or the entire board scrubbed in the sink. Once the correct PCB is written the board gets a few coats of varnish to protect it. It does require some soldering for connections etc, but it would simplify "one off" production.

My sons Synth uses this system. Parts of the original test circuits being made on cornflakes cardboard...

Regards

Ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Dec 28 2018 12:00
Obviously showing my age here but I used to use a vero-pin prototyping system that was very similar to the hand-wired backplanes used on computers not so many years ago (well OK - about 40!). Then I moved to 'Veroboard' (a tradename I guess) but these days use a form of prototype board which is quite useful. I've not heard of your "ink" system Ralph, which sounds interesting, as soldering small jumper wires can get a bit annoying. Perhaps you could give a link to a good source?

With regards PCB production, I intend to take a lead from my MERG friends who use various PCB layout software systems and then send the 'Gerbers' (??) off to China for production. I was concerned that some of this software would just be another mountain to climb (together with 2D-CAD, 3D-CAD, Templot, IDEs - MPLab X, MMB etc) - which involves more time invested in side activities before getting back to the actual end project. However, they have suggested that a "part-timer" (like me) would find an open source product called 'Fritzing' very easy to learn and use - and that is what I will eventually do. Basically - it lets you draw a prototype board with connections, converts that to a circuit diagram and PCB layout - and most importantly generates a gerber file that the Chinese can use. So once you have a working prototype, hopefully it will be fairly easy to transform it into a more realiable and smaller end product. As I've mentioned, I have several things I'm working on and as the minimum PCB order is Qty 10 - will have some left over if others here wish to experiment.

Regards,

IanT 
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Dec 28 2018 12:39
This is the pen that we used.

https://www.amazon.co.uk/SODIAL-Conductive-Electronic-Instantly-Education/dp/B07CHGT4ZK/ref=sr_1_5?ie=UTF8&qid=1546000404&sr=8-5&keywords=silver%2Bconductive%2Bpen&th=1

The main ICs exist on protype Euro Cards. It is extremely easy to use.

regards

ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Dec 28 2018 13:49
In the days when car heated rear screens had a kind of printed/"transfer" surface element on the glass, you were able to buy a conductive silver repair pen in Halfords and similar car part shops. They were used to bridge any "burn outs" in the element. Presumably this the same stuff? Do Halfords still sell it?

John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Dec 28 2018 17:02
Was just re-reading this thread and it occurred to me that the Micromite Plus (which runs on the mid-range PIC32 chips - 64 & 100 pin versions) can already play WAV files directly from an SD card. I've not tried this on my E64, so I don't know exactly what sound quality is possible - but on the very fast PIC32 MZ chip (which runs a very powerful version of MMBasic called 'eXtreme') - I found the following note:

"Extended WAV File Playback: The Micromite eXtreme can play WAV files (like the Micromite Plus) however, if the eXtreme is configured to run at 252 Mhz it is also capable of playing WAV files recorded with sampling rates of 24 KHz and 48 KHz." This sounds quite impressive but in truth I've no real idea what is required in practice for our applications...

My 'on-board' thoughts have thus far been directed at the simple 'Micromite' using the simplest/slowest 28 pin device that runs MM Basic. The larger chips are (x5) faster, have a lot more memory and a lot more I/O. They also run enhanced versions of MMB (Plus & eXtreme) which are backwards compatible with the 'basic' MMB version - so anything written for the simpler chip will run on the faster ones but not vice versa where the enhanced features have been used.

My main reason for using the 28pin DIP was for ease of soldering but now I'm beginning to solder-flow SMD devices, some of that logic is starting to fade away it seems...

One thing at a time though... my H-Bridge has finally arrived.

Regards,

IanT


P.S.   Thank you Ralph - I'll order one to try.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Dec 28 2018 17:27
As we get the sound project(s) underway, I think we will find all sorts of cards at all sorts of prices to suit everybodies pockets. Nice work identifying another source of bits though Ian.
As far as the sampling rate is concerned, I record at 24bit 88.2Khz, and load my projects at 16bit 44.1Khz (CD quality) purely because the sound format I use allows a greater dynamic range to be recorded than lower sampling formats.
Almost all but the MiTroniks card (16bit 44.1Khz) are low bitrate cards 8bits through to 11bits although there is some conjecture as to what Dallee, PhoenixZIMO and Loksound are using these days, they certainly don't sound like 16bit samples being played from my last listening review.
I was working with the designer of the MiTroniks card and played a Class 56 file through his three way Hi-Fi speaker system, and from three feet away you could feel the engine vibrations trying to punch a hole your ribs.
There are techniques that easily dispel the fallacy that good quality sound cannot be played through small speakers- even down to OO gauge!, it is the sound chip (processor) that determines the poor quality.

As to how to integrate with Radio Control etc
Ralph and Tim introduced me to a Radio Transmitter and Receiver which has multiple push buttons and outouts which can be routed to the inputs of the audio cards to select and play relevant sounds.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Dec 28 2018 22:01
Sound is not a real priority for me at the moment - but I found this post on (what is effectively) the Micromite Forum. To be honest, I'd never heard of 'FLAC' before but others seem to think it's better than WAV and it's now an integral part of the MMB (Plus & eXtreme) language.

https://www.thebackshed.com/forum/forum_posts.asp?TID=9395&KW=FLAC

The supported 'FLAC' sampling rates are given below and they seem to be within Doddys' performance criteria.

44.1KHz 16-bit (CD quality) and 24-bit
48.0KHz 16-bit and 24-bit
88.2KHz 16-bit and 24-bit
96.0KHz 24-bit
192.0KHz 24-bit (252MHz CPU only)

As one of the I2S DAC devices (that the FLAC s/w uses) is listed at £2.62 - an E64 system (plus a 32Gb SD card) with this device would be an interesting sound solution and still have enough processor/memory bandwidth to handle a radio control link and any other engine I/O required. You could look at this as an on-board engine controller with an optional sound device that costs about £2-£3 - or a dedicated 32Gb engine sound system (for about £40). You also need the sound files too of course.

As you say Doddy - there are probably many ways to do these things but as I already use the MM system for other stuff, it's nice to have these options available if I need them.

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Dec 29 2018 08:34
Nice research Ian!  :D

.FLAC files use a lossless codec to compress audio files, unlike .MP3 files which loose audio data.

In that guise the compact nature of the files would be useful for applications where onboard storage memory is at a premium. The .FLAC format is also very good for audio archiving.

The downside for us, is that for Diesel, Electric and maybe some Steam projects, the use of .FLAC files will increase the usage of the processor chip as the .FLAC files will need to be decoded (unpacked) before they can be played.

For continual streaming and one-shot sounds that should not present a problem, however when you are stitching samples together . . ?

If the onboard processor chip has to fetch and carry .FLAC sound samples, then decode them, there is an inherrent risk that latency maybe introduced in between different sound samples thus leading to a potentially unsatisfactory audio scenario producing gaps in the audio output stream where as close to zero latency is really required.

The MiTroniks sound card I mentioned in earlier postings, has the ability to have the sound files stored on a swappable Micro-SD card, thus allowing a different sound project to be loaded by the user but retain the original hardware.

NB: If an original MiTroniks sound project like a Class 20 locomotive is required to be changed to a Class 66 then you just purchase a new Micro-SD card for £29. (https://www.mtroniks.net/cat/Sound-Systems-For-Scale-Models) Although I am very sure MiTroniks would like you to purchase an entirely new Controller/Sound Unit for £300+

Within the powerup cycle of the MiTroniks sound card the contents of the Micro-SD card are loaded into the processors memory thus minimising the considerable latency issues presented by trying to read files from external memory cards.

For the Diesel Horn, Klaxon and Steam Whistle projects that John and Ralph have described where short,  single-shot audio files are played, I have no doubt that .FLAC configured devices will present no issues.It maybe, that an entire Steam project could be configured this way. Diesels and Electric projects - Nah I am really not convinced on that one.

The next question is to how many internal audio channels are available with such cards and how the relative internal audio streams volumes are adjusted and mixed down together to Stereo or Mono audio outputs?



Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Dec 29 2018 10:40
Yes, as I understand it the system is streaming data off the SD card directly into the I2S channel - and once set-up there is very little processor overhead. At that level the programming required comprises a few lines. "Stitching" these files together would require a lot more intervention I imagine. Since sound volume is controlled down-stream (in the DAC system) - I wonder if it would be possible to 'mix' several analogue signals to achieve the same result?

I have no idea what is possible with the larger (MZ) chips, as I've never needed the performance but they might support two channels that could be mixed under program control. It is possible to throw a dedicated processor at a problem with MMB - as it supports both Master & Slave I2C modes - which means you can control 'secondary' MMB systems from the main one (an example is given in the manual).

Back to the "Now" - started to look at driving the DRV8871 (H-Bridge) chip from my little (28 pin) MM - and it looks fairly straightforward - hope my confidence isn't misplaced!

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Dec 29 2018 10:48
I have sneaked out... The time slicing problem is a valid one. Stereo could be produced by sending alternate sound pulses to the two speakers in much the same way FM stereo or CD-4 worked.

A simple "switch case" loop could detect buttons and feed that to the selected speaker. I personally would decompress the FLAC file to save on cpu time and store it as a serial file. Given the fact that 16gB SDs are now sold at the local co-op - file sizes are no longer a problem!!!

The FM stereo timing frequency is 19kHz the CD-4 was over 30kHz. If we stick to a nice number of 20kHz then this gives us a nice mathematical number to work with!

I have to gey back to work...

Regards

Ralph
Title: The Stereo Pair or 2 x Mono Audio Channels
Post by: Doddy on Dec 29 2018 17:33
Ralph,

What I should have described to you is a Stereo pair, both Left and Right channels operating as seperate Mono outputs.


All you need is Left channel, Right channel or Left+Right channel. You are entirely correct on the .FLAC unpacking and latency timing issues though.

My plan for the Peak Diesel and other projects, was to use two or maybe three Stereo sound cards and produce a distributed sound system throughout the model.

(https://i.ibb.co/bQYK8Rs/BR45-Logic-Diagram.png) (https://ibb.co/bQYK8Rs)

That way, the Air Compressor and Vacuum exhauster can sound in the relevant nose, Brake Noises and track squeal from the relevant bogie, Air Horns from the relevant driving Cab, and engine sounds centrally in the bodyshell.

Radio Control from the Deltang Rx Receivers trigger Outputs wired to the Soundcards trigger Inputs for user operated Air Horns, Start-up and Shutdown sequences . . . Guards Whistle . . . etc


Of course, all of this is possible on one soundcard with a single speaker like most commerical products.  8) As long as you have multiple internal audio channels and an onboard mixer, otherwise the sampled sounds will play over each other. Yes Ian, you can edit the files to cover two (or more) sounds at the same time, but you loose all flexibility of dynamically changing the audio output - the result sounds terrible.


Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Dec 30 2018 11:56
Robert,
From what you have described it looks like you are going to have to build a "truth table" of actions.
Viz:
Loco decellerates, brake sounds = yes.

The table gets boiled down to a set of rules from which the "switch case" loops can be built. The entire thing will have to be a set of loops within loops, each loop operating on one parameter to decide what to do.

I know it sounds complex but it is actually quite simple. The problem is more your end Robert! Two distinct sound channels are easy, how you blend and mix them into a "dual mono" system to produce a sound to your liking I have to leave to you....

Regards

Ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Dec 30 2018 13:58
Robert,
From what you have described it looks like you are going to have to build a "truth table" of actions.
Viz:

Loco decellerates, brake sounds = yes.

I know it sounds complex but it is actually quite simple.

Yes, I know I have been doing this for myself and various major toy manufacturers since 2007
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Apr 10 2019 09:43
Found this on Gavin's youtube channel this morning . . .

https://youtu.be/8TOpFqgL4C0

The epitome of G3 in the Garden? It's got to be very close for me.

I just love the colours of the trains and having standard and narrow gauge running together- sublime!  8) 8) 8)

Doddy

PS: Nice garden too!
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Apr 10 2019 10:23
Here is Warton Road, as seen at National Garden Railway Show (Peterborough), last Saturday.

https://www.youtube.com/watch?v=KtmflWnBnNM

Worthy of note is the model of the 100HP Sentinel (in grey primer) which is the first of the "production" models arising from the "Plantagenet" project. The model was being test-run, having recently been completed).

There is an initial batch of four which will soon available for sale (through the G3S) and a second batch is at the planning stage.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Branch on Apr 18 2019 19:36
You'll have to build it with air-operated doors (or at least simulated air operation)!
To be realistic they will have to open and shut several times before the starting signal bell will "ping".......memories of the Northern Line commute from Morden in the 1960's!

John.
Strange as it may seem, I have (after a year or so of frustrating R&D), got the doors to work on my G class (later Q23) District line motor car.  When I have the rest of it together, I'll share how it was done, this will prevent anyone else going down the same series of blind alleys as me!

John Branch
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Apr 19 2019 09:32
Quote
I have (after a year or so of frustrating R&D), got the doors to work on my G class (later Q23) District line motor car.

Well done.....this I must see!

Regards,
John.
Title: For no other reason than . .
Post by: Doddy on May 17 2019 15:12
to see if I can.

After a pleasent weekend photographing ex-LT1938 tube stock on the I-O-W. I decided to see how to drive the 2'  7" wheels from an ex-DVD motor.

First the new Griffon Hovercraft

(https://i.ibb.co/RT3dFMX/20190511-110607.jpg) (https://ibb.co/RT3dFMX)


And delapidated tube stock at St Johns Depot

(https://i.ibb.co/tb3QqJ0/20190511-140454.jpg) (https://ibb.co/tb3QqJ0)


And a bite to eat at the Ryde Pier cafe - well in order! Service was excellent and freshly cooked food - delicious!

(https://i.ibb.co/nqpCXRW/20190511-150857.jpg) (https://ibb.co/nqpCXRW)

After establishing that the wheels axle needs to turn at 500rpm to achieve a prototypical 45 mph, the DVD motor is rated at 6500 rpm. Calculating a double reduction gearbox using this website proved useful.

http://www.smex.net.au/Reference/Ratios02.php

Prior to that Ineeded to understand the relationship between an Axles rotational  speed and Miles Per Hour. So back to the PC and a short blast on an Excel spreadsheet.

(https://i.ibb.co/8DbrnP9/1938-Tube-Stock-jpeg.jpg) (https://ibb.co/8DbrnP9)


Using the SMEX calculator I derived a 13:1 double reduction gearbox configuration.

(https://i.ibb.co/2SZRD4L/SMEX-jpeg.jpg) (https://ibb.co/2SZRD4L)

I don't intend building a tube train, but found the process helpful to get my mind around gearbox design. I trust others will find the information useful to them.

Doddy
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Peaky 556 on May 17 2019 21:34
“...the DVD motor is rated at 6500 rpm.”

Just capturing a line from Doddy’s workings, as a general comment to anybody thinking of designing or choosing their own gearbox or ratio, it is not appropriate to use the free running speed of the motor.   Not that I’m assuming the 6500 rpm is the free running speed in Doddy’s case, but the reality is that maximum power is achieved at about 50% of free running speed. 

Consequently if we hope to work a small power unit hard to get the top speed we want, it’s probably wise to gear the motor for 50% revs at the speed we want.  Then if power is a bit marginal, it’s more likely to run as we want, and if it’s overpowered, it’s just a matter of treading gently on the ‘go’ pedal.

Generally these thoughts are a bit academic though, as most suppliers of motor-gearbox units wouldn’t tell you the speeds or ratios anyway!

Regards,
Tim
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on May 17 2019 23:38
My thoughts exactly Tim, many thanks for drawing them out.

Your assumption of my using a maximum speed at 6500rpm is therefore correct.

In the case of any potential 1938 'Tube' car, I envisaged that I would not want it operating much (if at all) above a scale 35mph, so the 50% powerloss would have been almost irrelevant in my particular case.

As for monitoring the motor speed, I just treated myself to one of those hand held laser gadgets you use yourself to count the rpm on spindles - cost £8.72 inc p+p comes complete from Guangdong with a Chinese 'dump Trump' cap and flag.

Doddy
Title: Stumped in Scotland
Post by: Doddy on Jun 04 2019 12:55
Normally, I am on the ball so to speak, but cannot identify where this photo was taken.

Any takers?

(https://i.ibb.co/VxdDy7x/2a427b07a046c079aca93c0155d79ac7.jpg) (https://ibb.co/VxdDy7x)
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Jun 04 2019 14:47
Fort William

John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Jul 24 2019 10:59
Just recently I saw a photo from this DVD and decided to get a copy, fortunately the MIBA website still has them, they are rather old as the former Big Boy of Dobwalls Theme Park was presented.

(https://i.ibb.co/7rmz19m/MIBA-Gartenbahn.jpg) (https://ibb.co/7rmz19m)
 
The stock of Dobwalls was dispersed across the globe many years ago, I seem to remember that the Big Boy sold for about £250,000.
Nonetheless, Bob Symes (Robert Alexander Baron Schutzmann von Schutzmansdorff (6 May 1924 – 19 January 2015)) introduces another Austrian chap whose father built a rather nice 1:27.5 scale Railway in his garden.

(https://i.ibb.co/hgPt7jx/OBB-1670-back.jpg) (https://ibb.co/hgPt7jx)

(https://i.ibb.co/fxx4JNZ/OBB-1670-LOK.jpg) (https://ibb.co/fxx4JNZ)

(https://i.ibb.co/9ZhbWhg/OBB-1670-side.jpg) (https://ibb.co/9ZhbWhg)

(https://i.ibb.co/9yZZ011/OBB-Station.jpg) (https://ibb.co/9yZZ011)

(https://i.ibb.co/Qb7Rk9k/OBB-Wien.jpg) (https://ibb.co/Qb7Rk9k)

If this is what can be done in 52mm gauge (1:27.5) then G3 (1:22.58) offers just that little bit extra scope for railway modelling. Either way, to see a near G3 scale train in this environment is truly heart warming and one that I find rather inspirational.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Jul 24 2019 17:02
1:22.58 Doddy - what happened to 1:22.6 ?

IanT

P.S. Like the railway though...
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Jul 24 2019 17:34
Here we go around the Mulberry bush . . .

1 foot = 304.8 mm

304.8 mm / 13.5 mm = 22.577777777
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Jul 24 2019 20:24
Sorry Robert but the metre is now defined as a numner of Cadmium Red wavelengths and your accuracy is still way out...

Regards

Ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Jul 24 2019 23:28
I'm afraid not - G3 is 2.5" gauge and we model UK standard gauge at 4ft 81/2" - all imperial measurements

That's 56.5"/2.5" = 22.6.

No (Metric) Mulberry Bushes were involved (or harmed) in this calculation...

Regards,

IanT

Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Jul 25 2019 06:16
This is the third time we have had this dicussion and I for one, I am thoroughly sick and tired of this pedantic discourse. Clearly you have a bee in your bonnet that needs to be cleared out.


If it is so wrong in your mind, then why not (for the second or third time of asking) get the G3 society website updated with the correct information? It does not appear on the technical standards webpage either.


(https://i.ibb.co/zHPfLy4/G3-track-Gauge.jpg) (https://ibb.co/zHPfLy4)

Perhaps a word in the ear of the webmaster to make the changes needed? . . .  Ooops my bad!
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Jul 25 2019 09:01
Oh dear!

Let's not "nitpick" over fractions of a mm (or thousandths of an inch) .... very few of our models are likely to be precisely to scale anyway ...... measuring and cutting, material shrinkage (resin and plastics) all contrive to introduce errors....add to that the fact that a great many of the available "scale" drawings include errors.
There is a body of opinion which says, "if it looks right", then that's good enough.

John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Jul 25 2019 09:49
I don't see any problem with the Website.

Between the wars, most G3 modellers moved to 17/32" scale (from 1/2") as it was very much nearer the correct ratio and also gave a bit more space. With the advent of metrication - some (including myself) found 13.5mm to be a convenient ratio to work to. Now 17/32 = 13.494mm and 13.5mm = 0.5315" (17/32" = 0.53125") - so they are not exactly the same but are very close. A 30ft loco built to 17/32nd would be 404.82mm long, at 13.5mm it would be 405mm long and at (an exact) scale of 1:22.6 it would be 404.6mm long. So, I agree that there is virtually no difference in practice whether one uses one of the "rules-of-thumb" or the correct scaling factor. However - if you are going to use a scaling factor - why not use the right one?

These days I use 22.6 because it is so very simple to draw in CAD a full sized prototype and then just simply scale it by 22.6. I also find it convenient to just divide any full sized measurement by 22.6 to get its scale equivalent - although I will then probably convert it into mm most of the time.

As to a bee in my bonnet - well initially I thought I was just pointing out a simple fact. However, having meditated on the issue, I've decide I probably do have a bit a buzz in my noggin. It probably started many years ago when GRS started calling Gauge 3 - "G64" - because I guess they didn't want to call it "G63.5".

It died away for a while but resurfaced a year or two ago, when the G3S announced on it's banners that the scale was 1:22.5 (same as LGB).

And then there was the most recent occasion when Garden Rail insisted on heading their Sentinel article as being a "1:22.5" scale article - and also actually changed the text to say I'd designed the loco at 1:22.5 - which as you may have gathered from above was incorrect - the Sentinel was most definitely scaled at 1:22.6.

What's the practical difference, well not a lot at all really - but why change things that don't need to be changed.

Gauge 3 is blessed with having a single gauge and scale and in that we are unique when compared to the larger model railway gauges G0 & G1. If someone wants to build at 1:22.58 or 1:22.3 - then of course they are very welcome to do so - I really don't care. But if you are going to post things as "facts" then let's try to stick to the actual scale ratios.

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Jul 25 2019 15:30
Posting things as facts when the blinkers are on and the facts not properly represented on the G3 website really irks when you then get repeatedly criticised for making an observation.
In the absence of specifically stating the scale ratio on the G3 website and its corresponding technical pages leaves everything open to debate.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Jul 25 2019 15:45
Gentlemen, please, can we draw a line under this and agree to disagree. 

There appears to be a range of views, particularly in the "commercial" world of G3, as to how the scale is to be referenced/defined.....the example of "Garden Rail" insisting on 1:25 (even though I explained to the author of the article, Mark Thatcher, that 1:26 was the scale used to construct the "Sentinel" locos) was to fit in with their inflexible method of "tagging" articles by scale (they use 1:25 for G3 since it is used by them for "G-scale" articles).

John
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Spitfire2865 on Jul 25 2019 16:19
We model 2 1/2" to the 4'8 1/2". I expect the society to reflect this ammendment in their next website update. /s

UPDATE: Trevor made contact through moderation channels and apologises, having made this comment "tongue in cheek" and, on reflection, having realised it was probably unhelpful to have done so.
JC
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: MikeWilliams on Jul 25 2019 17:43
Well, I assumed the "criticism" of Doddy was intended to be humrous, and will continue to believe that.

However, I would like to be pedantic over:
... measuring and cutting, material shrinkage (resin and plastics) all contrive to introduce errors....

I would simply like to point out that some metals expand more than plastics or resins.  I have a resin van with brass door runners and in the blazing heat a few years ago the brass expanded and buckled - the resin stayed put.

Mike
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Peaky 556 on Jul 25 2019 19:20
Personally I’m a keen supporter of using the “correct” scale factor of 22.6, and it rather irks me to see 22.5 on the Society banner.  Maybe it’s a mistake of course, and it’s not the only one on those banners.  In support of the people who put them together some years ago, I know as a former design draughtsman just how easy it is to painstakingly put together a drawing title or note, only to find it mis-spelt as a result of the slow and laborious process of creating it.  What I cannot excuse however is the lack of peer review before production of something so important as a society promotion banner.

Anyhow, we digress.  The reason for 22.6 was succinctly made by IanT further up this page, and this is why we ought to be quoting the magic 22.6 number in our technical standards.  Whilst we need not mandate this scale, it is only right and proper that we acknowledge and promote its use as the technically correct number.  The measurements of 17/32” or 13.5mm to the foot need to be placed in context as approximate conversions.

I think that’s all I have to say on the matter, so, happy modelling!
Tim
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Jul 25 2019 19:31
Mike,

The shrinkage to which I referred was in respect of the mould-making process and resin-casting process itself, where the standard advice is to allow for possible shrinkage of up to 1 percent when producing the patterns.
I have also observed that after extended time (a few years) some silicone moulds can themselves shrink (seems to be a consequence of leeching of the "oily" component in the mix). Certain brands of silicone and resin seem to suffer more than others.

As an apparent example of the shrinkage problem, I was tackled by Peter Korzelius at the 2018 AGM who had bought one of the Flexikit LMS "steel" van bodies from you with the intention of mounting it on one of his steel underframes. He said the dimensions of sides and ends weren't matching/consistent and he had difficulty assembling it. I explained that I had supplied the moulds and each side and end would have been cast from the same mould and the only explanations I could offer were that either the resin was from a different batch/mix or there was a delay in casting the second side/end, during which the mould had shrunk.

Regarding whitemetal/pewter casting, I read somewhere that, when cooling, the castings expand (not contract as I would have assumed) although I have never encountered any significant/observable evidence of that. I guess the expansion is akin to water/ice and the molten metal taking on a crystalline structure.

I remember you telling me about the problem with the LSWR van door at the time it was introduced (a good few years ago now)! I subsequently altered my original pattern/mould to cater for a plastic card runner fixed to the resin with brass rivets.

Regards,
John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: MikeWilliams on Jul 26 2019 16:40
Well John, I am amazed because those castings were done within the space of a few days, and odd that he never mention it to me.  Think they were a gift as a trial actually, rather than "bought".

But, without wishing to prolong the 1:22.6 debate further(!) what I really meant was that its not only resin models which expand and contract - metal and wood do too, at least as much.

Mike
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: John Candy on Jul 26 2019 19:41
Quote
odd that he never mention it to me.  Think they were a gift as a trial actually, rather than "bought".

Mike,
I guess that, being a gift, he didn't like to appear ungrateful.
I saw the body (which had been assembled around a plywood box) on his table at the show and (out of curiosity, since it looked to be from my original patterns) asked from whence it had come. He said from you and then became critical of the quality. At that point I explained that I had made the patterns and moulds and that my own examples fitted perfectly and that it would be odd if the sides and ends were dimensionally different since they would have been cast in the the same moulds.
I don't suppose you can now remember the time of year or temperature at which the parts were cast but I do wonder whether a great variation in ambient temperature and/or humidity could have been the cause.
Regards,
John.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: MikeWilliams on Jul 26 2019 21:17
No, sorry.  I don't remember.  It was about five years ago!
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Doddy on Jul 27 2019 15:59
If you are going to post things as "facts" then let's try to stick to the actual scale ratios.
I see where you are coming from now, many thanks for pointing this out to me, I apologise to you.
Doddy
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: IanT on Jul 27 2019 19:26
No problem Doddy - I didn't set out to upset you and I'm sorry if I did so.

There are not too many places (online) that people can find out about G3 and this is one of them - so it's important we try to keep the key facts both simple and consistent here for anyone new to our gauge/scale.

I'll be looking at that webpage and will endeavour to make it clearer.

Regards,

IanT
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Jul 27 2019 20:33
Having been brought up in a totally Metric environment... I will admit that it is easier for me to think of G3 as a gauge of 6.35cm rather than 2.5".  I have always worked from direct Metric reduction by dividing everything by 22.6 or previously 19.1 Although the model people look best at 24th scale(?) As fas as possible I have tried to make my models to the correct scale, but if there are a suitable set of plans at 22.5 -I will unhesitatingly use them!!!

Most of my drawing are taken from "00" scale A4 spiral bound books. These are I have to assume are as accurate as possible. Some of the plans I have will produce a good model but not a scale model. The Chriss Barron; Peak and 2-nol are a case in point. Both are too short. But both are the correct length not to "side swipe" another wagon if taken on 3.3m radius curves.

I have built a Golwe locomotive in SM32 which was over 118cm long but would corner a std SM32 setcurve with ease. This worked only because of the sheer bloody mindedness of the builder to produce a working Golwe articulated. The same thing happened when I built the Tasmanian J Hagans. Only by very close scale modelling did both systems work.

Absolute scale fidelity does have its place and without the drawings from Eurfort for the Hagans nothing would have worked. However I believe it is better to have a well designed working model than an exact shelf piece.

As to how the Hagans system works - it uses articulation via levers with moving fulcrums, the principle of a Golwe makes sense only after several shots of Polish Proof Spirit, but essentially it get longer the more it corners...

Regards

Ralph
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Spitfire2865 on Jul 28 2019 00:26
I just draw all my drawings to the scale of 13.5mm/ft.
Or for imperial drawings in inches, multiply inches by 1.125 to get the mm I need.
No need to ever think about how best to round a fraction of a scale. Besides, even our true gauge scale has its own setbacks. One being the B2B and subsequent chassis width. No point drawing 1:1 if its not going to work anyway. Best not waste the energy and instead get it right first time!
Hell, my American required significant revisions as I was working off fully dimesioned drawings and completely forgot the chassis width needed narrowing, which changed the cylinders, footplate, cab sidesheets, frame crossmembers, pilot, and firebox just to name a few!
Title: Ralphs Hagans and Golwé locomotives
Post by: Doddy on Jul 28 2019 06:26
Quite often Ralph leaves me in the dust with new ideas and topics, the Hagans and Golwé locomotives are no exception and appear to be in a league of their own.

Die Preußische T13, Bauart Hagans.

(https://i.ibb.co/hfmR2Kx/Preu-ische-T13-Bauart-Hagans.jpg) (https://ibb.co/hfmR2Kx)
(https://i.ibb.co/Fz6Fxvh/Preu-ische-T13-Bauart-Hagans-Heck.jpg) (https://ibb.co/Fz6Fxvh)

French Golwe locomotive for Ivory Coast railways.

(https://i.ibb.co/cFrT607/Golwe-locomotive.jpg) (https://ibb.co/cFrT607)

Hagans Tasmanian J class

(https://i.ibb.co/dG4VTbQ/hagans-Tasmainia-J.jpg) (https://ibb.co/dG4VTbQ)

(https://i.ibb.co/JRMSSC6/Hagans-patent-loco-small.jpg) (https://ibb.co/JRMSSC6)



References:
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: cabbage on Jul 28 2019 15:42
The main source of information I have are the actual book detailing the Tasmanian J and "Meyer and Meyer like articulated locomotives".

For those of a strong stomach could I recommend "The Self Site" as it is called. The pages on "unusual locomotives" and "the museam of retrotech" will provide stomach upsetting information...

Regards

Ralph
Title: HollyWood Foundry - ScaleCalc App
Post by: Doddy on Aug 26 2019 08:55
Having used this software application for many years now, I have recently added the G3 ratio scale.

The software allows user configuration of different scales and makes the conversion from one scale to another possible, cross referencing the actual 1:1 dimensions in metric and imperial measures at the same time.


(https://i.ibb.co/6mtKsMm/HWFG3.png) (https://ibb.co/6mtKsMm)
Title: Bogie Compensation with Walsall Side Frames?
Post by: Doddy on Sep 15 2019 08:57
I am about ready to start assembling some Gloucester Bogies supplied by Wallsall Models, designed by Keith Smith.

(https://i.ibb.co/jf0g9qN/Gloucester-Bogie.jpg) (https://ibb.co/jf0g9qN)

Question is how to retain compensation of the sideframes? - assuming that the loose fit of the bearings is designed to do this - what design of bogie transom/crossbeam goes in between the two sideplates? The photo below shows the Walsall Models Orienstein & Koppel bogie sideframes which I suggest would work in the same way as my Gloucester Bogie design.


(https://i.ibb.co/HtkH8H1/DSCN3484.jpg) (https://ibb.co/HtkH8H1)

Any ideas from more experience modellers who have used these products and/or have knowledge of compensated bogie designs would be welcome here?

Many thanks in advance.
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Peaky 556 on Sep 15 2019 21:30
Doddy, my suggestion, if you want to use those side-frames and have compensation, is to have a piece of bent flat bar, with the ends bent down, joining the two via a new central hole drilled into each frame.  The fastener for each connection would be left slightly loose and thus enabled to pivot, thus providing the compensation.  A simple short screw and self-locking nut and a few flat washers would be needed.  I have tried this method with some prototype Blue Pullman bogies, but discovered that I hadn’t left quite enough rotational travel on each pivot so severe camber changes were not totally accommodated.  In principle it seemed to work ok.

Cheers, Tim
Title: Re: Doddys HaupWerkstatte - My build thread
Post by: Peaky 556 on Sep 15 2019 21:42
Ignore the gears and you should see the basic principle. 
Tim
(https://i.ibb.co/VNrT4y7/C46963-CB-C870-4704-91-AA-E4-A4-D23-F1254.jpg) (https://ibb.co/VNrT4y7)