Real cab controls for DCC locos

[Schooner]

Afternoon all, happy Friday!

 

Background

I got back into the hobby a year or so ago and made a start on a glorified tabletop Inglenook in 4mm (link in sig) to learn a bit about what I wanted/enjoyed nowadays.

 

Whilst the short answer is 'pre-Grouping quayside shunting', this process is ongoing and one desire that has repeatedly come up is to explore 7mm, so...a glorified tabletop Inglenook in 7mm it is!

 

Inspired by:

 

I got to something like:

305mm/1ft squares. Scenic layout shewn, supported by a fiddlestick/cassette on either side.

 

I enjoy tactile interaction with the layout and think this is more viable in 1:43 than 1:76, so it's 3-link couplings (although I've moved to these in 4mm too, and I will place uncoupling magnets for Dinghams by way of future-proofing the 7mm layout), point levers (DCC Concepts S-levers, as used on the 4mm layout), manual TT control etc.

 

There's a ship and a crane, a baseboard in build, a loco in the hand and one on order...so things are past the point of no return. Time to deal with the last unknowns then.

 

First question - simple stage one:

What DCC system would you recommend for such a small layout, with an equally tiny stud of tiny pre-Grouping 0-4-0Ts?

 

There's a ton of information out there, but I'm finding it hard to parse down to meet my lowly requirements and would appreciate your advice.

 

The system only needs to drive the locos; point control will be independent and 'accessory' control will be manual. What would be best way to achieve this in your view?

 

DCC might seem overkill - indeed I certainly thought so for 4mm, and re-used my old Gaugemaster controller. This, at its best and in conjunction with good locos, does deliver the excellent slow-speed control which is a non-negotiable requirement for me. However, I know that DCC would improve things, and the 4mm was wired with this in mind so the ability to shift control system between layouts would be an advantage.

 

The thing which really swung it for me, however, was not slow-speed control...nor sound...but both of those in conjunction with

No way I can see that and not go for it!

 

So, what do you reckon would be the best way to go by way of control set up?

 

 

Stage two:

Given the above, anything to increase challenge and immersion in the world of the layout would be welcomed. 'Real' controls, for example...

 

The layout will be operated largely from a seated position, front and centre...as if in front of a computer. On computers, many hobbyists have a dedicated control interface for their chosen fantasies: rally drivers have wheels and pedals, pilots have throttle and flightsticks etc. Railsimmers, it seems, only have little control boxes designed to mimic diesel/electric loco controls.

 

What I had in mind was something more akin to...

:)

 

As a first stab, and from a position of profound ignorance but aided in that I only have to mimic little old industrials, I wondered if something like

 

could be reasonably DCC'd as

• Regulator                -             Throttle function
• Brake                       -             Brake function (likely horizontal, rather than vertical, for ergonomics)
• Reverser                 -              Direction select function (likely screw reverser, atypical though this would be, also for ergonomics)
• Steam Blower        -             Smoke function
• Injector Valve        -              Function select increase (discrete rotary)
• Water Feed Value -             Function select decrease (discrete rotary)
• Whistle Valve        -              Function on/off toggle

 

Additional instruments:

• Water Gauge             -        hour-glass style water clock, to match the longevity of 'steam' production from the TRS system
• Pressure Gauge        -        layout voltage display
• Cylinder Drain Cock -        Cylinder Drain function
• Sander Lever             -        ???
• ???                               -         Loco I.D. input + selector / cycle?

 

Firebox hollow and full of knee :)

 

A) Is this possible?

B) Is it plausible?

C) How on earth to go about it?!

 

I have a couple of ideas for the hardware side, but I'm sure that's already plenty to get the ball rolling. It's the electronics - how to get the reverser lever to do what it should etc - which are magic to me! 

 

Thanks for your time, and in advance for your opinions and help!

 

Schooner

Edited April 21, 2023 by Schooner
Title updated to better reflect thread content!

[Nigelcliffe]

All possible.  What's your budget, or your skill level in programming ?

 

DCC control, at a basic level, anything will work.  Whatever you want to use.  Reliable running will come from fitting stay-alive units inside the locomotives (or forgetting track pickup and using a battery system and some form of radio control). 

 

 

The fancy SIM control cab onto DCC - commercially Roco offer something along those lines through their Z21, its App, and can work onto a video feed of the layout.  I don't think that's the only commercial option.   
Or, its do-able within JMRI (but it isn't "just click here", there's some setup to do which might get into coding).  

 

 

- Nigel

[Schooner]

2 minutes ago, Nigelcliffe said:

What's your budget, or your skill level in programming ?

Non-minimal and absolutely minimal respectively. The latter is more easily increased that the former, predictably, and something I'm fairly keen to explore anyway.

 

So the first step is to pick a bog-standard plug and play option, like the NCE Powercab/Roco's equivalent starter set? Seems overkill, but simple :)

 

Interestingly (YMMV) battery and remote control is also on the list of things to try, but one thing at a time...!

 

41 minutes ago, Nigelcliffe said:

...commercially Roco offer something along those lines through their Z21, its App...

This sort of thing?

Not exactly what I had in mind, but layout-integration wise that's got to be the right ballpark.

 

JMRI looks, at first glance, to be more in line with what I was thinking and a good place to start reading. Thanks!

[Nigelcliffe]

If willing to do things with computers and smartphones, and into tech-tinkering,  then I'd suggest building a DCC++EX system (change out of £60, plug-together building bricks, no soldering), and controlling it from computer and/or phone/tablet.   Then see where the software options take you.  
There's a very cheap option to add a physical USB knob to an Android phone running the EngineDriver app. 

 

 

I'm working on a hardware throttle at the moment, it will communicate on WiThrottle process (DCC++EX, and/or JMRI).   Processor is a £6 Raspberry PI Pico-W.   Basic code is working in that my Pico-W can select a loco and adjust speed, direction and functions.  There's quite a lot more to do. 

 

 

[NIK]

Hi,

 

Selection of the DCC system I think depends on the implementation of the steam loco 'cab'.

 

I think a steam loco cab 'can' be done. My approach would be a JMRI script to deal with talking to the DCC system and modelling the behaviour of some of the aspects of the steam loco. I don't know how the steam effect unit you mention works. It may require the script to estimate when it will run out of 'steam'.

 

I think at least one DCC decoder can simulate water and coal use and feed that info back to a control system via Railcom.

 

Might need a microcontroller to interface to the physical controls but having fluid in the water level indicators might be a challenge. The microcontroller would interface to the JMRI script.

 

So the DCC system for such an implementation would have a JMRI compatible interface and Railcom capability.

 

Regards

 

Nik

[Schooner]

4 hours ago, NIK said:

I don't know how the steam effect unit you mention works.

I suspect we can look here for an accessible DIY equivalent in a related hobby-sphere. So no worries about timing the steam 'running out' - when the tank is empty that's your lot! I wonder what CV simulates a stuck safety valve followed by boiler explosion...

...then again, maybe one of those was enough...!*

 

My mention of water gauges was more to find a use for them, being a prominent feature on the real thing. Using the gauges as a timer, calibrated for the length of time the 'smoke' unit can produce smoke before it's used up all the water in the tank, would give both useful information (knowing when it's about time to stop and refill the tank) and also act as something of a clock to play against/keep score when operating the layout in 'pure' shunting puzzle mode :)

 

IIUC then, the interface between me and the model goes something like:

• Hand - mechanical control (eg. brass lever of the cylinder drain cock)
• Mechanical control - electronic control (eg. two position rotary switch)
• Electronic control - electronic signal (circuit made)
• Signal read by JMRI, programmed to interpret it as 'Activate Function 21 (eg) Cylinder Drain Sound and Function 27 Cylinder Drain Smoke'
• Converted signal of appropriate format sent by JMRI to DCC command station, which weaves its magic
• Magical spell sent to loco, which obediently does a passable impression of blowing its cylinder drains

I appreciate there's quite a lot involved behind all those steps, but is that the gist of how such a system might work?

 

*Just to make it absolutely clear, the photo documents what happens when you're not gentle enough trying to prise wayward Liquid Gravity out out the cavity of a 3D-printed bodykit using an awl and then place the pieces back on the chassis for dramatic effect. Nothing to do with smoke units of any kind!

 

Edited April 21, 2023 by Schooner

[NIK]

Hi,

 

Looks like the loco has had a RUD or Rapid Unscheduled Disassembly as happened to SpaceX's latest test flight.

 

Regards

 

Nik

[Schooner]

Indeed!

 

It does make watching the launches particularly exciting when there's a very real chance of things going boom. This time I thought it was a rather elegant disintegration compared to some of the previous Starship terminations!

[Pacific231G]

On 21/04/2023 at 21:23, Schooner said:

Indeed!

 

It does make watching the launches particularly exciting when there's a very real chance of things going boom. This time I thought it was a rather elegant disintegration compared to some of the previous Starship terminations!

When it has once got into orbit without blowing up they'll try it with people: shades of "Those Magnificent Men..."  (but in reality most early aviation pioneers died from flying accidents)

Edited April 26, 2023 by Pacific231G
clarification of final clause

[Simond]

On 23/04/2023 at 12:27, Pacific231G said:

but in reality most early aviation pioneers died

I think it’s safe to say that all early aviation pioneers died, it’s the manner of said departure under consideration.  :)

 

Schooner’s question is interesting.  I’ve contented myself with knobs and buttons.

 

DCC allows quite a lot of Lego style assembly.  I purchased a Lenz system some 25 years ago, and am still using it, which has to be some kind of recommendation.  Lenz decoders, on the other hand, have not enjoyed the same longevity, and my go-to is Zimo, with KA.  My experience with my pal’s NCE is that I’d buy something else, ideally fully NMRA compliant.

 

There is/was a cab simulator some years back, the ZTC 511/611 which had a brake, gear lever, and throttle control, but no water gauges, injectors, blower, fire, handbrake, lubricators…. 

 

And there are lots of rail simulators with cab views, and cab controls, which are in many cases extremely accurate representations of their prototypes.  I’m not active in that arena at all, but I understand that such models are generated by individuals, so are presumably traded and comply with some form of interface standard.  
 

Building on what’s available, if you were to use the ZTC hardware, and a screen for your loco cab, the cab can change dependent on loco / decoder number selected, the gauges (steam pressure and water) can work, a decent hifi connection (turned up loud) for the safety valves, and you can spend the next thirty years learning to program to make it all work on JMRI…

 

not sure what you do about shovelling coal!

 

Following with interest

Simon

 

 

 

 

 

 

Edited April 26, 2023 by Simond

[Nigelcliffe]

The trouble with the ZTC system is you end up with a conflict over what controls the loco. 

 

The ZTC system worked internally to the throttle, so the regulator and brake levers worked together to determine when the device sent out speed changes.   You might change the regulator, and because of where other levers were positioned, no change in speed was sent.  

 

Inside the DCC decoder are further settings which determine speed.  There are the acceleration/deceleration settings which can delay a speed change.   So, with a decoder of the same vintage as the ZTC design, there are two things determining the loco acceleration/deceleration - the rate of change allowed on the output of the ZTC throttle, and the rate of change in the loco decoder, and the observed behaviour is the combination of both.   
More recently (the last 15 years+) some decoders have a "brake" function which will increase deceleration when a function instruction is received.     But, the ZTC's brake lever doesn't send those brake functions (it predates anyone thinking to add such features to decoders).   So, with those the ZTC "brake" does nothing, but instead a different function key has to be operated.   As that brake behaviour in the loco is often connected to sound as well as movement, a sound feature in a loco is lost.  Turning down the standard deceleration in the decoder will mean the "coasting" sound of a steam loco will be very short lived, so a loco would appear to "chuff almost all the time".   Trying to shoe-horn a recent sound decoder's behaviour into the ZTC throttle results in a very unsatisfactory experience.  (Unless one was to rip out the electronics inside the ZTC, just use the hardware levers and switches, and build a new throttle internals.   I have a design for the new electronics and throttle software which would be a starting point for such a project. )

 

 

"Start with an old ZTC" may work if one has a loco on the track which responds instantly to commands (no acceleration/deceleration) and all the "simulated behaviour" and sounds are done within the throttle system before instructions go to the track  (could be a wireless speaker link so the sound emerges from the loco).    Possible, but a lot of work.     

 

 

 

 

[Simond]

thanks Nigel,

 

I have never owned a ZTC controller, but was aware that there are some limitations - I guess the hardware is practical, perhaps rather nice, even if the internals need to be revised, to, for example, connect the brake to F2 - but of course, screwing down the brake is not the same as pressing a button. 

 

atb

Simon

 

 

 

[Steven B]

DCC throttle for a steam loco? With or without auto-fireman?

https://forum.mrhmag.com/post/an-operating-steam-throttle-you-can-customize-12548356

 

Steven B