DCC = Driving Carefully and Controlled ???

[Nigelcliffe]

54 minutes ago, Crosland said:

3 hours ago, Neil said:

Nine times out of ten a friendly hand will shoot out and restrain the runaway train whose wheels will scrabble round for a while until motion eventually ebbs away.

 

Does your system not allow emergency stop of the loco under control?

 

Don't touch the red button labelled "stop", you never know what it might do.    Only wimps read manuals. 

 

 

 

[pheaton]

19 hours ago, Pete the Elaner said:

A reasonable acceleration & deceleration makes driving trains more fun. Surely that is why we got into the hobby in the first place?

A while back, a friend of mine spent all evening trying to stop an EMU at the the end of the platform on my layout. He could easily have slowed it down earlier & crawled into the station, but wanted to leave it as late as possible. This is a little like what drivers of real trains have to cope with when trying to keep or recover time.

 

Some decoders go one step further (particularly sound projects on Zimo decoders) by including a brake feature. Deceleration can be set to a decent value for coasting & if you want to slow down, hit the brake.

I am sure I have seen this on a Loksound v4 decoder too.

I understand most non-sound Zimo decoders can do this but I have not worked out how to set it up. I am sure it is all in the manual 

 

I find this a much more satisfying driving experience than turning a knob & seeing the loco instantly react.

The thing is though....we're scaling speed seemingly correctly....but i dont think some people scale time.....or possibly distance.....and now my brain hurts....

 

do we need to scale time? or have we not factored scale distance in the braking curves?

 

 

Edited August 2, 2019 by pheaton

[Pete the Elaner]

The only scaling of time is to cut out the pauses between train movements.

Other than that, "what looks right is right" is good enough for me.

[Neil]

1 hour ago, Nigelcliffe said:

 

Don't touch the red button labelled "stop", you never know what it might do.    Only wimps read manuals. 

 

 

 

 

Well that's no fun is it. It's a big system with many add on handsets which don't have the big red button, the man with the main controller may well be away making a brew or just away with the fairies however none of this negates my point that DCC is only as good as the person holding the handset.

[Dungrange]

17 minutes ago, pheaton said:

The thing is though....we're scaling speed seemingly correctly....but i dont think some people scale time.....or possibly distance.....and now my brain hurts....

 

do we need to scale time? or have we not factored scale distance in the braking curves?

 

There's no such thing as 'scale time'.  All we scale is distance, which is 1:76.2 if we are modelling in 4mm scale. 

 

However, we don't all have the space to produce a true scale model and often selectively compress distances.  You can also selectively compress time in the same way.  That is, you can cut out the pauses between train movements or even run the train a little slower so that it takes about the correct amount of time to cover our compressed distance.  However, since the distance is rarely compressed uniformly, it really is just a case of what looks right is right.  There is no magic formula to 'scale time' despite what some may try and argue.

[cravensdmufan]

On 01/08/2019 at 00:13, SRman said:

Speed adjustments may also be useful if you want to run two or more locos or units together. DCC allows you to match different characteristics more closely. In another topic there was a recent discussion on running multiple units together, and we got to Bachmann's class 150, which tends to have quite a low top speed, and Hornby's class 153, which has quite a high top speed. I haven't done this with mine (yet!), but the easy solution is to lower the class 153's top speed until it matches the 150 (which cannot be made to go any faster). 
 

I keep a circle of Hornby 4th radius set track for speed matching which I occasionally set up on laminate flooring much to Mrs CDF's amusement!   (Going back to my childhood!).

 

I find it much easier than trying to do it on the layout.

 

I did a Bachmann 150 + Hornby 153 just the other day, and a pair of Class 20s which I run nose to nose.

[Phil Bullock]

Setting CVs for top speed and appropriate acceleration/deceleration certainly adds to realism

 

And all the sound projects we have - 100 + - have a function which disables the inertia settings and reverts to direct drive. Far better for stopping/starting in the fiddle yard - but then reinstating the inertia once rolling means that the sound of thrash persists as the loco accelerates past the watching public.... most effective - or vice versa, accelerate up to top speed and then switch inertia back on and throttle back for nice coasting nosies - ohh, listen to that turbo over-run whistle on the MD655s in a Western....

 

Phil

 

 

[Tim V]

6 hours ago, Phil Bullock said:

 sound of thrash persists as the loco accelerates past the watching public.... most effective - or vice versa, accelerate up to top speed and then switch inertia back on and throttle back for nice coasting nosies - ohh, listen to that turbo over-run whistle on the MD655s in a Western....

 

 

When I'm next door watching a cracking pre-grouping layout ARGGH

[Phil Bullock]

Would that be tinplate Tim? Much louder than Dcc! Hee hee

[pauliebanger]

On 02/08/2019 at 08:18, Pete the Elaner said:

I agree that most brakes seem to effective. I guess the programmers prefer to provide something you can see easily, then you can back this off if required.

 

I can't remember where I got this from & have not got around to trying it yet but I have the below in my notes:

 

CV346 is the braking rate for Zimo decoders.

CV179 is braking rate for Loksound,  I think I may have 1 decoder which uses this.

For both, a lower value for braking rate makes the brake weaker.

 

Hi Pete,

Not quite correct for ZIMO. The CV to set which key to assign as the 'Brake Key' is CV309, the CV to set the brake force is CV 349. To reduce the effective brake force, the value in CV349 must be increased. (If you think of it as increasing the braking duration required it will make more sense).

 

The CVs to set and adjust the manual brakes on ZIMO non-sound decoders are identical to those above for sound decoders.

 

Decoder software version V34.0 later is required for this feature to be enabled - one good reason to have a ZIMO decoder update device as even older decoders can be refreshed to 'as new' condition feature-wise by uploading the latest decoder software. The same device will also enable you to upload/reblow your own ZIMO sound decoders with your own soujnd files or with those from established (accredited) sound providers sent to you via email. (I can do this for any of my projects).

 

Best regards,

 

Paul

 

 

 

[pauliebanger]

On 01/08/2019 at 23:51, SRman said:

I agree, Pete. I have a few Zimo sound projects with the brake on F2 function. However, the brakes seem to me to be too effective, and I would like to make the trains take longer to stop if the F2 key is held rather than jabbed every so often. I'm sure this braking rate is also adjustable, but I haven't yet investigated this properly.

 

 

Jeff,

 

I don't wish to suggest that you do not know the following, but I include it for the sake of any reader who may not have 'hands-on' experience with real locos.

 

As you probably know, I designed the Progressive Brake Key feature for ZIMO decoders. My aim was to replicate how the Brake control was operated in all the steam and diesel locos that I have driven and all that I have observed whilst on the footplate.

 

If you have a high value in CV4 the model will have realistic momentum and consequently authentic looking coasting. As mentioned earlier in this thread this results in difficulty in stopping precisely where desired.

 

The Brake Key feature in ZIMO decoders helps to make it possible to stop reliably and in a controlled way.

 

Holding the brake key 'on' should only be used to simulate a controlled emergency stop - (not the dead stop of a 'Red Button' press) but the maximum force the train is capable of applying. The CV349 value sets this rate.

 

Fortunately I have never been involved with such an emergency. Mostly, the speed is controlled by anticipation of power required and the driver's experience of the loco, road and the train weight/brake force available info passed to him/her by the guard before the trip commences where applicable. When braking is required it is most often to trim speed to suit local conditions or to stop at signals or stations etc. In these cases applying the brake control continuously would result in everyone on board having their tea emptied into their laps.

 

To brake smoothly and steadily the driver will apply brake force intermittently as the first part of the brake duration has little impact on speed reduction compared the rate of deceleration at low speed with same brake force.

 

The ZIMO brake feature imitates this in this way if used with a 'momentary' key - this is why it is assigned to F2 in my projects (and adopted by other providers, probably for similar reasons) as this key is often the only one which can be used as 'momentary' with many (mainly US design) controllers.

 

When you press the F2 brake key there is a (few milleseconds) delay before the brake force is applied. After this initial period, a small proportion of the maximum brake force is applied, after another short duration a higher percentage of the maximum is applied, and so on as long as there is movement and the brake key is held 'on'. The longer the duration of each brake application the harder they 'bite' until just before stopping, the brake force is at maximum. This why the action of the ZIMO brake feature is progressive.

 

So you will see that a series of short 'dabs' will produce an average brake force much less that full application (brake key held on). You can control this average brake force by the way in which you operate the brake key. This is directly analagous with real brake performance.

 

I recognise that some operators will not wish for this level of immersion and so the ability to vary the brake force is available at CV349. (This also allows operators to equip their locos with very good or with less efficient brakes - this was the primary consideration when designing the feature).

 

My projects come with the ability to select either light engine or heavy train (usually on F5) when the the brake force is also automatically adjusted to suit either case. (Light Engines can usually stop more quickly than when hauling a heavy train). This will be the case even if a user varies the maximum rate via CV349.

 

This means that if you engage F5 before or even during braking, the brake force can be immediately increased, giving additional control of brake performance in real time.

 

A further enhancement is possible with CV394 Bit 6. If this Bit is active it will produce a 'parking brake' effect. Opening the throttle will rev the engines, but the model will not move until brakes are released. You can use this this to simulate part of the 'brake test' performed before movements commence.

 

I think I covered all the most likely scenarios of this feature during its design.

 

Best regards,

 

Paul

Edited August 20, 2019 by pauliebanger

[pauliebanger]

On 02/08/2019 at 12:31, Phil Bullock said:

Setting CVs for top speed and appropriate acceleration/deceleration certainly adds to realism

 

And all the sound projects we have - 100 + - have a function which disables the inertia settings and reverts to direct drive. Far better for stopping/starting in the fiddle yard - but then reinstating the inertia once rolling means that the sound of thrash persists as the loco accelerates past the watching public.... most effective - or vice versa, accelerate up to top speed and then switch inertia back on and throttle back for nice coasting nosies - ohh, listen to that turbo over-run whistle on the MD655s in a Western....

 

Phil

 

 

 

This 'Direct Drive' key has also been possible with ZIMO decoders for as long as I can remember.

 

It is incorporated into many ZIMO sound projects as 'Shunt Mode',for which it is eminently suited. It can be set up on any ZIMO decoder very easily.

 

CV156 sets the operating key

 

CV124 sets the desired reduction in CVs 3 and 4 if the key specified in CV156 in engaged. (CV124 = 3 removes all inertia and momentum).

 

Best regards,

 

Paul

[melmerby]

On 01/08/2019 at 00:13, SRman said:

Speed adjustments may also be useful if you want to run two or more locos or units together. DCC allows you to match different characteristics more closely. In another topic there was a recent discussion on running multiple units together, and we got to Bachmann's class 150, which tends to have quite a low top speed, and Hornby's class 153, which has quite a high top speed. I haven't done this with mine (yet!), but the easy solution is to lower the class 153's top speed until it matches the 150 (which cannot be made to go any faster). 
 

If you use a computer control program you don't need to speed match, the program does that anyway.

Just lash 2 (or more) together and the will drive as one.

[SRman]

2 hours ago, pauliebanger said:

 

Jeff,

 

I don't wish to suggest that you do not know the following, but I include it for the sake of any reader who may not have 'hands-on' experience with real locos.

 

As you probably know, I designed the Progressive Brake Key feature for ZIMO decoders. My aim was to replicate how the Brake control was operated in all the steam and diesel locos that I have driven and all that I have observed whilst on the footplate.

 

If you have a high value in CV4 the model will have realistic momentum and consequently authentic looking coasting. As mentioned earlier in this thread this results in difficulty in stopping precisely where desired.

 

The Brake Key feature in ZIMO decoders helps to make it possible to stop reliably and in a controlled way.

 

Holding the brake key 'on' should only be used to simulate a controlled emergency stop - (not the dead stop of a 'Red Button' press) but the maximum force the train is capable of applying. The CV349 value sets this rate.

 

Fortunately I have never been involved with such an emergency. Mostly, the speed is controlled by anticipation of power required and the driver's experience of the loco, road and the train weight/brake force available info passed to him/her by the guard before the trip commences where applicable. When braking is required it is most often to trim speed to suit local conditions or to stop at signals or stations etc. In these cases applying the brake control continuously would result in everyone on board having their tea emptied into their laps.

 

To brake smoothly and steadily the driver will apply brake force intermittently as the first part of the brake duration has little impact on speed reduction compared the rate of deceleration at low speed with same brake force.

 

<snipped>

 

Best regards,

 

Paul

 

 

Hi Paul,

 

I didn't want to swamp this post with the whole of your reply so forgive me for cutting it down. I agree with most of what you say, but I found that doing very quick, short dabs on F2 was also not particularly realistic for me. As such, I wanted a compromise between the extremely short dabs on F2 of the original set up, and using a series of longer presses, thus simulating some of what you describe, where the brake is applied by the driver, then eased off a bit, see-sawing between two or more braking rates. Playing with CVs 4 and 349 allow a better compromise for my way of thinking (and driving!), although it almost certainly won't suit everyone. By holding F2 for a longer period, I get the higher braking rate, then releasing it, I get the lower rate set in CV4.

To be honest, I haven't quite got this right, yet, but I think I am close to achieving my goal. I will publish the final settings once I play with them a bit more. 

I should add, that my layout has quite a long continuous run, and the settings I choose won't be so good for a smaller layout or an end to end one.

Even an emergency brake application on the real things can take quite a long distance to stop, and can also result in wheel flats if the wheels lock. In my case, if all else fails and I really need an instant stop, there are always the big red buttons on my NCE cabs.

[w124bob]

Driving a (model)train correctly is as much about attitude and observation as CV settings, how many of us actually pause after coupling up, for instance. Guard/shunter dives under to put the pipes on, strolls down to release the handbrakes, etc . There are no CV settings for this it's just about thinking how the real thing is done, even something as simple as an engine running into a yard. Stop the loco short, get some instructions off the shunter , change a couple of points . Youtube and DVD's are priceless for this, take time to watch the background as well as the big shiney loco. Try to learn a little about the loco's you have and how the real thing reacts, a class 31 for example, had a very different feel to the power handle,  more clicks. This made it slower to operate(the mechanics of the handle)then throw in the ponderous over weight nature of the 31. I picked up this attitude watching and reading certain US modellers(I have US stock) as well my personal footplate career experience. Ulitmatley it's just enjoying yourself, so ignore the ramblings of an insomniac!

Edited September 4, 2019 by w124bob

[AMJ]

Even on DC I used to have to think carefully whilst driving the Wren BR standard 4 as it used to take some time to accelerate and with the weight etc used to take some time to stop.

 

It can be fun shunting where you have left a gap between some wagons and then you forget to slow down and end up having to go under to uncouple them.  Or run into the buffer stop!

 

How many SPAD's are there by drivers not slowing down enough?

[Phil S]

With the Roco Multimaus Family, the 'STOP' button on each individual handset can be set to 1 of 3 options:     Stop and remove power from the layout,   Stop (Broadcast Zero Speed) but keep track power

and rather usefully STOP ONLY YOUR currently controlled LOCO - leaving all others running unaffected.

 

With our shunting puzzles (G Scale) - which we get the visitors to operate - they find it useful (when they realise) that if the STOP is local to only their controller ( and we set it so it is, so as they don't stop other trains running on the 'distractor' track at the back ) - as they can stop their loco PRECISELY at the position where the uncoupling ramp has released the wagon - from which they can then restart the loco in the opposite direction without risk of recoupling.

 

We always operate with 1 cabled controller - as an emergency backup - and this is probably set to to stop all ( either of the first 2 options )  ... and the wireless handsets  can then be stop only your own...

HOWEVER - care has to be taken of the battery-saving time-out option which switches the handset off ... and this CAN cause the whole system to STOP. (Again an option).

 

On the shunting puzzle, locos are programmed down to only 1/4 to 1/2 normal speed range. Some inertia is programmed  ... use the 'shunting button' would be inappropriate as they are always shunting.

(I always think it was a bad error that Hornby omitted CV5 from their basic loco decoder !!)

 

A 'downside' of programmed inertia CAN be that the operator simply uses the knob as a pre-set maximum speed switch [ much like driving a modern emu ??? ] - relying on the programmed inertia to provide the smoothing.  'DIRECT' CONTROL' - in the hands of someone trying to simulate a real loco - can be used effectively.

I have found the CONFLICT to be when a loco is intended to be operated by computer - especially if it has sound - is that the computer wants micro-control (direct drive) but the sound file is best driven with appropriate slugging to match. ... perhaps such stock is not intended to be moved between layouts.