DCC Controller with coast and brake

[pauliebanger]

Well, I seem to have stirred up a hornet's nest, here, much of which I don't understand and will never want to understand.

 

Three things seem to me to be relevant:

 

1) I am interested in the interface between my hands and the device I am using to impart commands to the train, so whether or not that device is the controller or the decoder does not really interest me. Life is rapidly getting too short for such niceties to be learnt - I just want it to work!

 

2) if I read the discussion of the Zimo brake function correctly once you have embarked on braking the train one is only able then to increase the level of braking, whereas in real life one would usually make a gentle application of the brakes to check the speed then release them, allowing the train to coast before making a final brake application to stop the train

 

3) I did not mention sound because I recognise that this is another can of worms or hornet's nest or what have you. I'm mostly interested in steam trains so I definitely do not want them to chuff unless I open the regulator to allow steam in, whereas many systems seem to  start chuffing of their own accord when they decelerate to a certain speed. It seems t me that when you have a system which allows acceleration, coasting and braking as three separate states then it should be straightforward to create the appropriate sounds for each of these states?

 

I'm sorry if this issue has been addressed above but after the third reference to a cv I'm afraid my on-board decoder tends to switch off...

 

Ian (Confused of Askrigg)

 

Ian,

 

Agreed, in trying to give a full picture so that you can make informed decisions, rather more information than was strictly necessary flowed out.

 

Don't worry, you do not need to understand (lots of folk have little idea how modern cars 'work', but they can still successfully drive them and benefit from all the convenience programmed in).

 

However, if you go back to post #3, the way in which ZIMO coasting and braking work is explained sufficiently for a working understanding.

 

Addressing your points above.

 

1 )  It works, and without requiring a specialised DCC command station.

 

2 )  Not quite. The increase in the braking rate is the internal way a ZIMO decoder operates the simulated braking force to mimic real brake action. For your purposes you can disregard that technical discussion. Be assured, the observable result is exactly as you would wish it. Short dabs give light retardation, longer applications give heavier retardation. That is how it is on the real thing. Your description of real life braking and coasting is exactly what you can achieve with the ZIMO Brake Key.

 

3 )  Well constructed Steam sound projects will provide not only the appropriate sounds for the three states you mention, acceleration, coasting (drifting) and braking, but cruising too. Different cut-off percentages can be included and all my steam sound projects have switchable light engine/heavy train modes, each with  recordings of exhaust beats made at different reverser positions. This enables a strident exhaust sound under hard acceleration or a more gentle sound with modest acceleration.

 

Kind regards,

 

Paul

[Junctionmad]

1 You obviously misunderstood my explanation on the ZIMO Brake Key function. It is not an 'all (simulated) brake force on or all off' binary system. ZIMO's is a significant departure from all previous attempts at brake simulation.

2 Decoder manufacturers realise that there are other sources of locomotive power than steam, so their systems have to be suitable for all.

 

3 The very act of applying, releasing and re-applying brakes in real locos is a manual version of adjusting the duty cycle to create some intermediary effect. If your 'binary' analysis of the operation of Westinghouse brakes is correct, the driver is simulating a variable brake force by intermittant application of a fixed force. Life imitating art?

 

Kind regards,

 

Paul

 

 

 

Paul I have a Zimo unit in front of me 

 

I was making one specific point 

 

 

The OP basically asked if he could get a throttle for DCC that was in effect similar to a DC inertia based controller with separate brake lever ( which in effect is just a parallel speed control in reality ) 

 

 

I was trying to point out that in DCC , this is actually quite difficult to do unless you are prepared to run dumb decoders with no inertia and then allow the Cab ( or controller , i.e. the DCC signal generator ) to control speed and simulate inertia in its software rather then in the decoders software 

 

 

If you opt for controlling inertia in the DCC throttle/controller then you can actually simulate what the old DC controller had,  ie continuously variable braking effect 

 

 

The problem as I pointed out with DCC, is that the protocol used between the throttle and the decoder, only transits speed ( or "desired" speed) .  there is no way to also transmit a variable "brake effect "

so to try and get around this , you can assign a function key to transit a code , that initiates a "simulation" of the applying of brakes. How this is done various from decoder to decoder , so there is no  consistent approach across decoders 

 

the result is all that can be done is repeated " presses" of the a Function key, which the decoder can interpret to modify the CV4 deceleration curve . ( and yes Zimos is a better implementation then others, but some are quite close , its not in anyway novel, as most decoder chips that actually support braking have a similar process, whereby repeatedly jabbing the function key causes a simulated increased braking effect  ( but only if you have the brake deceleration set quite low  in comparison to the CV4 figure of course ) 

 

To get the direct equivalent of a DC throttle with brake effect , would infact require you to produce the internal effects in the controller rather then the decoder. but this has severe disadvantages when you come to sound . The ZTC controller as far as I can determine , uses the concept of " train inertia" which is a function of the controller and not the decoder and it may be that the brake lever then merely controls that inertia and not any decoder based braking function 

 

what I was trying to say is that a direct equivalent of the continuous brake effect lever  that a DC throttle can have is actually virtually impossible to replicate in DCC unless you are prepared to hand all inertia  control/effects  to to the controller and not have any in the decoder . The closest we have using decoder interia is a push button binary brake signal , that can be used to approximate what the OP was looking for , but is not a direct replacement . Had the DCC protocol been modified to send a " brake variable " along with speed. then what the OP is looking for could easily have been provided for. but sadly it was not 

 

Dave 

[Junctionmad]

Ian,

 

Agreed, in trying to give a full picture so that you can make informed decisions, rather more information than was strictly necessary flowed out.

 

Don't worry, you do not need to understand (lots of folk have little idea how modern cars 'work', but they can still successfully drive them and benefit from all the convenience programmed in).

 

However, if you go back to post #3, the way in which ZIMO coasting and braking work is explained sufficiently for a working understanding.

 

Addressing your points above.

 

1 )  It works, and without requiring a specialised DCC command station.

 

2 )  Not quite. The increase in the braking rate is the internal way a ZIMO decoder operates the simulated braking force to mimic real brake action. For your purposes you can disregard that technical discussion. Be assured, the observable result is exactly as you would wish it. Short dabs give light retardation, longer applications give heavier retardation. That is how it is on the real thing. Your description of real life braking and coasting is exactly what you can achieve with the ZIMO Brake Key.

 

3 )  Well constructed Steam sound projects will provide not only the appropriate sounds for the three states you mention, acceleration, coasting (drifting) and braking, but cruising too. Different cut-off percentages can be included and all my steam sound projects have switchable light engine/heavy train modes, each with  recordings of exhaust beats made at different reverser positions. This enables a strident exhaust sound under hard acceleration or a more gentle sound with modest acceleration.

 

Kind regards,

 

Paul

 

I believe you are somewhat misleading  in what you are saying 

 

 

IN the Zimo system , which is not that dissimilar to others including Lenz and TCC, you set CV 346 to a rather low value and you have to set CV4 ( deceleration ) to a fairly high one, other wise the braking effect is lost. ( in TCC its CV120 from memory ) .  

Then when you close the throttle, the loco will decelerate under the control of CV4.  Repeated pushes of the designated brake function button , will apply the rate in CV346 for as long as the function key is pressed. 

 

SO the operation is not a direct copy of the original DC throttle and brake controller, but if you are happy with a series of button presses over a " continuous break lever " effect , then the difference is slight 

My experience is that other decoders also implement this feature in a similar way to Zimo. i.e. the brake function is available in a similar fashion as Zimo in most high end decoders 

 

as an aside , I find that in order to make DCC brake function look realistic , you have to set the CV4 high and have long " coast " times , this can make precision positioning of the loco difficult 

 

as a further aside , heres what you can really do with DCC throttles https://www.youtube.com/watch?v=xQXQ-iDxGz8. It also illustrates that the DC brake lever controller that the Op had was not actually replicated on the real thing ( as you pointed out ) , it was more of a binary on off ( even for vacuum train brakes ) in practice 

 

dave 

[pauliebanger]

Paul I have a Zimo unit in front of me 

 

I was making one specific point 

 

 

The OP basically asked if he could get a throttle for DCC that was in effect similar to a DC inertia based controller with separate brake lever ( which in effect is just a parallel speed control in reality ) 

 

 

I was trying to point out that in DCC , this is actually quite difficult to do unless you are prepared to run dumb decoders with no inertia and then allow the Cab ( or controller , i.e. the DCC signal generator ) to control speed and simulate inertia in its software rather then in the decoders software 

 

 

If you opt for controlling inertia in the DCC throttle/controller then you can actually simulate what the old DC controller had,  ie continuously variable braking effect 

 

 

The problem as I pointed out with DCC, is that the protocol used between the throttle and the decoder, only transits speed ( or "desired" speed) .  there is no way to also transmit a variable "brake effect "

so to try and get around this , you can assign a function key to transit a code , that initiates a "simulation" of the applying of brakes. How this is done various from decoder to decoder , so there is no  consistent approach across decoders 

 

the result is all that can be done is repeated " presses" of the a Function key, which the decoder can interpret to modify the CV4 deceleration curve . ( and yes Zimos is a better implementation then others, but some are quite close , its not in anyway novel, as most decoder chips that actually support braking have a similar process, whereby repeatedly jabbing the function key causes a simulated increased braking effect  ( but only if you have the brake deceleration set quite low  in comparison to the CV4 figure of course ) 

 

To get the direct equivalent of a DC throttle with brake effect , would infact require you to produce the internal effects in the controller rather then the decoder. but this has severe disadvantages when you come to sound . The ZTC controller as far as I can determine , uses the concept of " train inertia" which is a function of the controller and not the decoder and it may be that the brake lever then merely controls that inertia and not any decoder based braking function 

 

what I was trying to say is that a direct equivalent of the continuous brake effect lever  that a DC throttle can have is actually virtually impossible to replicate in DCC unless you are prepared to hand all inertia  control/effects  to to the controller and not have any in the decoder . The closest we have using decoder interia is a push button binary brake signal , that can be used to approximate what the OP was looking for , but is not a direct replacement . Had the DCC protocol been modified to send a " brake variable " along with speed. then what the OP is looking for could easily have been provided for. but sadly it was not 

 

Dave 

 

Dave,

 

Thank you for expanding on your meaning. I retain a different view.

 

The OP has already expressed confusion, he's not interested in how it works, just the practicalities of operation which I have summarised above.

 

Kind regards,

 

Paul

[Junctionmad]

OP, to see what can be done have a look at this 

 

this is just a standard DCC setup and non high end decoders 

 

decide for yourself if this approaches what you want 

[Junctionmad]

Dave,

 

Thank you for expanding on your meaning. I retain a different view.

 

The OP has already expressed confusion, he's not interested in how it works, just the practicalities of operation which I have summarised above.

 

Kind regards,

 

Paul

and you are mis directing him in that what the Zimo brake function is , it is  also achieved in many other decoders.  ( Ie repeated  brake function key use causes a perception of greater deceleration )

 

 

 

The OP has already expressed confusion, he's not interested in how it work

that may be so , but a basic understanding of DCC is needed to appreciate what he needs, but perhaps  " we are past listening to experts" phase .......

[Junctionmad]

 

. It seems t me that when you have a system which allows acceleration, coasting and braking as three separate states then it should be straightforward to create the appropriate sounds for each of these states?

 

indeed it is , the  previous situations where DCC sound chuffed to a halt is now very amateur hour indeed 

[clecklewyke]

OP, to see what can be done have a look at this https://www.youtube.com/watch?v=kYovzfNiFKQ

 

this is just a standard DCC setup and non high end decoders 

 

decide for yourself if this approaches what you want 

 

Most impressive. That felt like a real loco. I have a Judith Edge jackshaft shunter which makes the same sort of noises, courtesy of Modelyard and I will be using it for exactly that sort of switching, sorry, shunting, at Bradfprd North Western.

 

But I don't recognise the "controller".  I like its clunkiness. I suspect I would not be able to buy it off the shelf?

 

Ian

[Nigelcliffe]

Most impressive. That felt like a real loco. I have a Judith Edge jackshaft shunter which makes the same sort of noises, courtesy of Modelyard and I will be using it for exactly that sort of switching, sorry, shunting, at Bradfprd North Western.

 

But I don't recognise the "controller".  I like its clunkiness. I suspect I would not be able to buy it off the shelf?

 

Ian

 

The controller in the video is a modified NCE Cab04 throttle.   So, take one Cab04 and hack it about with additional switches.    I think "all" he's done is add in wires to the switches on the new panel back to push buttons on the Cab04, and then programmed the brake in the decoder to operate of a quick function key.   Not sure how the throttle is done, could be a new potentiometer (think that's what it is), or some sort of odd mechanical linkage.

 

 

 

 

 

- Nigel

[Junctionmad]

Most impressive. That felt like a real loco. I have a Judith Edge jackshaft shunter which makes the same sort of noises, courtesy of Modelyard and I will be using it for exactly that sort of switching, sorry, shunting, at Bradfprd North Western.

 

But I don't recognise the "controller". I like its clunkiness. I suspect I would not be able to buy it off the shelf?

 

Ian

The reason I posted it is that behind the scenes it's a standard nce throttle but the way dcc uses brake functions is nicely illustrated by the brake toggle switch. Each time the toggle is thrown it just sends a function key to the decoder to activate the brake deacceleration curve , keeping it thrown has the effect of keeping the brake decacceleration in place for a longer time resulting in faster slow down. You can see here that he has programmed in an aggressive braking deacceleration that suits a shunting loco

 

The exact same effects can be achieved with any standard dcc controller and a wide variety of decoder chips including ESU, zimo. Lenz, tcc and some Bachman chips.

 

It's not the same as the DC plus interia and brake lever , but in practice the results are similar

 

Note that there are subtle differences between decoder chips as to the exact method of simulating braking , but the overall results are the same

Dave

[Shropshire Lad]

Edited

[Junctionmad]

As an aside , I was reading through the various technical docs on the use of air and vacuum brakes on the real thing and was recently talking to an diesel engine driver about the use of vacuum brakes.  IN real life all these brakes were far more binary in use then the idea behind the throttle and brake lever DC controller setup . Essentially they were used between release , run  and on . In practice the driver fully applied then released then fully applied etc .  IN that regard therefore the DCC button is far closer to the prototype then the DC brake style variable lever , though its nearly not identical to the way conventional steam locomotives operated vacuum brakes  ( there is no concept of " release " in DCC )

 

 

Dave 

[Mike Storey]

As an aside , I was reading through the various technical docs on the use of air and vacuum brakes on the real thing and was recently talking to an diesel engine driver about the use of vacuum brakes.  IN real life all these brakes were far more binary in use then the idea behind the throttle and brake lever DC controller setup . Essentially they were used between release , run  and on . In practice the driver fully applied then released then fully applied etc .  IN that regard therefore the DCC button is far closer to the prototype then the DC brake style variable lever 

 

 

Dave 

 

Splitting hairs but....binary or not, the art of the loco driver (my brother was one for around 40 years) was to judge the braking so that his/her train stopped where it was supposed to. Dabbing at a button frantically does not do it for me. Moving a lever (or knob if pushed) to a certain position and waiting to see if I have got it right this time, or whether I have to apply more or less brake (usually less I found, in my reducing incompetence), is more fascinating and absorbing, for me. Others are not engrossed in this aspect of their hobby, and I fully respect that, in which case highly sophisticated braking simulation via button pressing will be perfectly adequate. I know you can achieve the former by doing the latter, but it still feels like typing not controlling a physical object. The chap in the video above who has adapted his NCE controller to look and feel a bit more like the real thing, is attempting to do this. Each to their own.

 

Where I worry is that my obsession with this may not sit well with the latest generation of sound chips, such as Paul provides (and they are really, really good), and I have a dilemma there. I know the old types worked Ok with a 511, as you had to intervene regularly to get the sounds you wanted, but the new ranges semi-automatically generate applicable sounds, once set for the style you wish. Has anyone tried a ZTC with a loco fitted with one of the real-drive or similar sound chips?

[Junctionmad]

 

 

The chap in the video above who has adapted his NCE controller to look and feel a bit more like the real thing, is attempting to do this. Each to their own.

yes but in fact all that is is button pushing 

 

 

I agree with your view on the lever , but the lever is in fact not representative of how a real train was braked.  in both air and vacuum, air was withdrawn/allowed in  till the driver , with his eye on the gauge , shut off the air/Vacumn , and that point he has applied a percentage of the total available brake force.  He didnt leave the brake lever on , as that would have drained all vacuum .  Once he  reached his desired braking rate, he put the brake lever back to "run" or "lap"  SO the control of braking consisted on repeated applications of the brake lever.  This is more closely related to the push button effect in DCC then it is to the brake lever in a DC interia and brake controller. The lever on the DC throttle is mor like the action of the brake pedal in a car, rather then the way a train actually brakes 

[Mike Storey]

yes but in fact all that is is button pushing 

 

 

I agree with your view on the lever , but the lever is in fact not representative of how a real train was braked.  in both air and vacuum, air was withdrawn/allowed in  till the driver , with his eye on the gauge , shut off the air/Vacumn , and that point he has applied a percentage of the total available brake force.  He didnt leave the brake lever on , as that would have drained all vacuum .  Once he  reached his desired braking rate, he put the brake lever back to "run" or "lap"  SO the control of braking consisted on repeated applications of the brake lever.  This is more closely related to the push button effect in DCC then it is to the brake lever in a DC interia and brake controller. The lever on the DC throttle is mor like the action of the brake pedal in a car, rather then the way a train actually brakes 

 

Nah, not true IMHO. Dabbing the button, via a button or via a cleverly disguised lever dabbing a button, only puts the brake on. With a lever worked through the DC Inertia or DCC braked controller (only ZTC to my very uncertain knowledge), you take the brake off, when you think you have reached the desired braking rate, just like the real thing. That's the point of it. Unless I have severely misunderstood how the brake inertia simulation on the majority of DCC controllers works - because I have NEVER seen the equivalent of releasing the brakes on such controllers being used other than on DC or the ZTC - then the truth is the complete reverse of what you have stated. I am very happy to be corrected!!

[Junctionmad]

Nah, not true IMHO. Dabbing the button, via a button or via a cleverly disguised lever dabbing a button, only puts the brake on. With a lever worked through the DC Inertia or DCC braked controller (only ZTC to my very uncertain knowledge), you take the brake off, when you think you have reached the desired braking rate, just like the real thing. That's the point of it. Unless I have severely misunderstood how the brake inertia simulation on the majority of DCC controllers works - because I have NEVER seen the equivalent of releasing the brakes on such controllers being used other than on DC or the ZTC - then the truth is the complete reverse of what you have stated. I am very happy to be corrected!!

From memory all a DC throttle with a brake lever did, was to adjust the capacitor based rate slowdown by paralleling the brake lever resistance across the standard slowdown resistor. Hence for a given brake lever position what resulted was an increased slow down rate, once the brake lever was returned to zero the remaining charge on the capacitor drained away at the original decay rate.

 

This is very similar to the brake pedal of a car. ( in fact it's virtually identical ) for a given pedal pressure ( aka brake lever position ) you got a given deceleration rate. More brake pressure ( aka moving the lever more ) produces an increased deceleration rate. Removing pressure from the pedal ( aka returning the brake lever to zero ) causes the deceleration to return to the original coasting rate ( albeit at a lower speed)

 

This is not how , the brake valve, on the automatic vacuum brake actually works. Leaving the brake valve partially open ( ie the equivalent of moving the DC brake lever to a set position ) actually simply causes air to be admitted to the train pipe. As that air is admitted brake pressure increases. If the driver were to leave that lever in position , quite quickly all vacuum would be destroyed and a near lock of the wheels would result. Hence in use the driver switches repeatedly between brake on and running , each cycle causes increased brake pressure. This is

similar to a button push

 

However dccc does not faithfully reproduce all aspects of the brake sequence

 

What typically happens is cv4 contains a slow deceleration and the brake CV contains a faster one ( often 5-10 times faster ) reduce the throttle to zero and the train coasts to a halt at the CV4 rate. Push the brake button and the deceleration curve In the brake CV is substituted for the duration of the button push repeated pushing of the button merely ensures the brake deaceleration stays in place longer.

 

So a single push of the brake button , represents a brake valve being moved from released to on and once the brake deceleration is reached , returned to the running position , when the button is released in effect, vacuum release takes place and the brakes come off. Dcc equally cannot correctly emulate the release running on three positions but it comes closer then the lever in the DC throttle does

[Mike Storey]

From memory all a DC throttle with a brake lever did, was to adjust the capacitor based rate slowdown by paralleling the brake lever resistance across the standard slowdown resistor. Hence for a given brake lever position what resulted was an increased slow down rate, once the brake lever was returned to zero the remaining charge on the capacitor drained away at the original decay rate.

 

This is very similar to the brake pedal of a car. ( in fact it's virtually identical ) for a given pedal pressure ( aka brake lever position ) you got a given deceleration rate. More brake pressure ( aka moving the lever more ) produces an increased deceleration rate. Removing pressure from the pedal ( aka returning the brake lever to zero ) causes the deceleration to return to the original coasting rate ( albeit at a lower speed)

 

This is not how , the brake valve, on the automatic vacuum brake actually works. Leaving the brake valve partially open ( ie the equivalent of moving the DC brake lever to a set position ) actually simply causes air to be admitted to the train pipe. As that air is admitted brake pressure increases. If the driver were to leave that lever in position , quite quickly all vacuum would be destroyed and a near lock of the wheels would result. Hence in use the driver switches repeatedly between brake on and running , each cycle causes increased brake pressure. This is

similar to a button push

 

However dccc does not faithfully reproduce all aspects of the brake sequence

 

What typically happens is cv4 contains a slow deceleration and the brake CV contains a faster one ( often 5-10 times faster ) reduce the throttle to zero and the train coasts to a halt at the CV4 rate. Push the brake button and the deceleration curve In the brake CV is substituted for the duration of the button push repeated pushing of the button merely ensures the brake deaceleration stays in place longer.

 

So a single push of the brake button , represents a brake valve being moved from released to on and once the brake deceleration is reached , returned to the running position , when the button is released in effect, vacuum release takes place and the brakes come off. Dcc equally cannot correctly emulate the release running on three positions but it comes closer then the lever in the DC throttle does

 

Thanks for that and I bow to your technical knowledge, but this is not what I observed in my use of DC throttle and brake systems of some years ago. Once you set the throttle to zero/off, and applied the brake lever/knob, you waited until you thought the train/loco had decelerated enough to stop where you hoped it would, and set the brake back to zero/off. The train would not then resume its previous speed, but continue at the new speed and you then applied the brake again to control the final few feet, probably more than once more if you were crap at it, as I was for some time. In my couple of days using a ZTC 511 to do the same, I observed the same effect, and liked it a lot.

 

I think what you are saying is that button dabbing does much the same thing, but that you do not take the brake "off", in effect causing a continuous controlled deceleration by virtue of the pre-programming.

 

Whether or not the technicalities of direct control as apposed to pre-programmed simulation (and I fully appreciate that simulation behind the scenes is also involved in apparently direct control), replicate the train or car brake, the actual effect of human simulation of the actions of a loco driver, are far more realistic where a separate brake lever/knob is provided, because you can take the brake off and on again, instead of just constantly increasing it. You can do that too if you want!

 

I accept it is a matter of taste and will not matter to most people, so won't push it. But I would still like to know if my Luddite tendencies will spoil the use of the new generation of clever sound chips, for therein lies a dilemma. I love sound far too much than is healthy, especially after experiencing the SLW Class 24, and I would not want to lose that far superior realism for the sake of a knob.....

[number6]

Fascinating thread. As an ex user of an H&M Walkabout and now DCC, the way the Walkabout - with its brake button - worked was very satisfying and I've not experienced anything like it with my DCC kit.

 

It may not have replicated what a real driver does with vacuum or air brakes but it did give an impression of mass and inertia. 'Applying the brakes' became the way to control the engine and train rather than the throttle. I used to keep the power on and run only using the brake button. My uncle (also a Driver for many years) always said getting going is easy, the hard bit is stopping.

 

If it wasn't for all the other aspects of DCC that beat analogue hands down I'd still be using the Walkabout.

 

Look forward to someone cracking this in a simple and elegant way.

[SRman]

How about the Digitrax Zephyr / Zephyr Xtra starter sets? http://www.digitrax.com/products/starter-sets/zepx/

[Mike Storey]

How about the Digitrax Zephyr / Zephyr Xtra starter sets? http://www.digitrax.com/products/starter-sets/zepx/

 

Never have used an Xtra but did use a Zephyr on a friend's layout for a while. It is very good value for money, for what it does, but I simply did not get on with it - it felt tinny and lightweight, despite the appearance, and changing the FWD/Brake/REV knob was a delicate exercise. Not something you could do without thinking as you drove a loco. When in brake function, it worked well enough, but I much preferred the separate lever on a ZTC. However, that came/comes at a price. I stuck with my Dynamis, which was cheap but irritating, until I could afford something better, or prices dropped. Then the ACE came out at a really good price. Another compromise, but much better, especially when using all the functions on sound decoders. But the most recent sound decoders are now making that functionality increasingly redundant.

 

My friend ditched the Zephyr for an NCE a year or two later, but is also now thinking hard about a ZTC 611, but he will probably wait until the further upgrades, to a full size screen and suchlike. I get the impression he may have a long wait though.

[Junctionmad]

My own view s the DC brake lever is just as unprotptypical as the DC button , even if the lever , to a car driving population , seems to be " familiar " as it operates similar to a brake pedal on a car.

 

The dcc button as I mentioned before is equally a compromise because the operation of the automatic train trade is not properly simulated using it either.

 

Really at the end of the ot boils to " what rocks your boat "

 

It's unfortunate that modern dcc decoders do not implement a braking algorithm closer to the operation of the automatic train brake.

[number6]

What I don't understand about those who say 'I don't want one because a brake button causes unprototypical braking behaviour' is the the way that DCC accelerates is just as unprototypical!

 

I suppose you could argue that speed steps are like notches or cut-off but I've never seen a model loco move off in anything but a slightly too slow or far too jerky manner. I would argue that drifting to a halt, checking the rate of deceleration - giving the sense of mass is much more obvious in stopping and a 'apply brake' button, lever or valve would be really usefully in replicating that.

 

I understand how brakes work on the real thing and I've ridden on and watched enough of the real things to know what I am trying to copy in model form and I think that is hard to replicate elegantly or feel connected to by just using one speed control (dial, button or inertia setting).

[Junctionmad]

What I don't understand about those who say 'I don't want one because a brake button causes unprototypical braking behaviour' is the the way that DCC accelerates is just as unprototypical!

 

I suppose you could argue that speed steps are like notches or cut-off but I've never seen a model loco move off in anything but a slightly too slow or far too jerky manner. I would argue that drifting to a halt, checking the rate of deceleration - giving the sense of mass is much more obvious in stopping and a 'apply brake' button, lever or valve would be really usefully in replicating that.

 

I understand how brakes work on the real thing and I've ridden on and watched enough of the real things to know what I am trying to copy in model form and I think that is hard to replicate elegantly or feel connected to by just using one speed control (dial, button or inertia setting).

 

 

 

The simplest solution is no solution, just replicate the prototype , i.e. implement a system that simulates the automatic train brake.  The issue of course is that in real life , quite a skill needed to be developed to bring a train to a halt smoothly and the mass and inertia of the real thing played a huge part.  for most people, simple inertia is as sufficient as they want for need in replicating the prototype.  I mean how many layouts actually implement  all the signalling rules either . In reality a model railway is not a simulation of the prototype , its just a " model railway " 

 

 

dave

[pauliebanger]

and you are mis directing him in that what the Zimo brake function is , it is  also achieved in many other decoders.  ( Ie repeated  brake function key use causes a perception of greater deceleration )

 

that may be so , but a basic understanding of DCC is needed to appreciate what he needs, but perhaps  " we are past listening to experts" phase .......

 

Dave,

 

I am mis directing (sic) no one.

 

You claim that the ZIMO Brake Key works the same as all others. This appears to be based upon your analysis that the deceleration rate provided by the value in CV4 is applicable except when the Brake Key is engaged when the value in CV349 is substituted.

 

That is not correct.

 

Continuing to repeat your theory as if it were fact is misleading.

 

Kind regards,

 

Paul

[pauliebanger]

Thanks for that and I bow to your technical knowledge, but this is not what I observed in my use of DC throttle and brake systems of some years ago. Once you set the throttle to zero/off, and applied the brake lever/knob, you waited until you thought the train/loco had decelerated enough to stop where you hoped it would, and set the brake back to zero/off. The train would not then resume its previous speed, but continue at the new speed and you then applied the brake again to control the final few feet, probably more than once more if you were crap at it, as I was for some time. In my couple of days using a ZTC 511 to do the same, I observed the same effect, and liked it a lot.

 

I think what you are saying is that button dabbing does much the same thing, but that you do not take the brake "off", in effect causing a continuous controlled deceleration by virtue of the pre-programming.

 

Whether or not the technicalities of direct control as apposed to pre-programmed simulation (and I fully appreciate that simulation behind the scenes is also involved in apparently direct control), replicate the train or car brake, the actual effect of human simulation of the actions of a loco driver, are far more realistic where a separate brake lever/knob is provided, because you can take the brake off and on again, instead of just constantly increasing it. You can do that too if you want!

 

I accept it is a matter of taste and will not matter to most people, so won't push it. But I would still like to know if my Luddite tendencies will spoil the use of the new generation of clever sound chips, for therein lies a dilemma. I love sound far too much than is healthy, especially after experiencing the SLW Class 24, and I would not want to lose that far superior realism for the sake of a knob.....

 

Mike,

 

I'd be careful about bowing to anyone's supposed technical knowledge unless you can be certain that it stands up to scrutiny. LOL.

 

I'll respond to your points in order.

 

Your observations are correct. In real life a brake application is made and cancelled (repeatedly if necessary) in order to obtain the correct retardation. The force applied and the duration of application produces the effect.

 

What you describe, apply brake, release it and the model resumes coasting but from a new, lower, speed, is exactly the response you will get from ZIMO Brake Key. You will note that I suggest assigning a 'momentary' action key i.e. the key continues to issue brake commands as long as it is pressed. (A latched key would need to be pressed once for On and again for Off, so is less convenient).

 

The effect of using the Brake Key to over-ride the throttle setting means that it is possible to use the brake key to slow the loco, but when released the original speed will be resumed. You quite rightly identify this as being non-prototypical. ZIMO does not work in this fashion.

 

I'm not sure that Dave was suggesting a 'continuous controlled deceleration' but in any case, that is also not how ZIMO works.

 

The ZIMO Brake Key is a separate control which physically and mentally separates the functions applying power from that of applying brakes. It is a key, rather than a windy handle, but essentially it has the sameoperation. Short dab is like a quick small wind on/off, sustained hold is equivalent to winding on full brake, and dabs of intermediary duration will give an effect between the two extremes. You can definitely release all Brake Force by releasing the Brake Key.

 

But if you have the SLW Class 4 you will know all this already. It is fully explained in the comprehensive User Manual. Just try it out. Set the model going, reduce the speed steps requested, then use the Brake Key, F2 (or if you use an NCE PowerCab, use the Horn key as it is the only 'momentary action' key on a PowerCab). As well as the sound of the brake application, you will see the model slow as I have described. quick dab, minor speed correction, longer hold, progressively greater speed reduction.

 

If you have been using it on analogue, pending purchase of a DCC controller, then the feature is automatically removed, since you do not have a button to which the ZIMO brake key feature can be assigned.

 

This will automatically be restored when using any DCC controller, including ZTC.

 

However, the on board brake feature makes the ZTC brake winder redundant as ZIMO's implementation is a superior simulation of the real thing.

 

If you really believe that you cannot live without the ZTC user interface (and I should confess here that I have owned a ZTC for around 25 years so I do understand your perspective) then ZIMO decoders are designed to be easilly customised by owners without recourse to specialist equipment or programs.

 

Any DCC controller which can write values to CVs can be used to remove the Brake Key feature, and to reduce CVs 3 and 4 to low values, say 3 in each. The decoder will then rely on the train inertia and brake feature within the ZTC.

 

As to the sounds I lovingly crafted into the Class 24 project, it would be a real shame to loose them, would it not?

 

Fortunately, this is a ZIMO, which does not (and never has) relied upon high values in CVs 3 and 4 to make the engine sounds work in prototypical manner. So, though I have not tried this myself, it should not interfere unduely with the sound project. I cannot give the same reassurance with regard to sound projects in other brands.

 

Please bear in mind that the Class 24 sound project was specifically designed for the SLW model and its characteristics. Changing CVs 3 and 4 might not affect the way that the engine sounds are played, but it will impact on the running characteristics. How much so will depend upon the quality of the ZTC inertia and momentum implementation.

 

My recommendation. Give the ZIMO Brake Key a thorough trial before committing to the ZTC. After all, it's already included so there's no premium to pay, and if you can't be reconciled, you can save up for the ZTC. (Or I'll sell you mine as I have no practical use for it anymore, LOL).

 

Kind regards,

 

Paul