The wife's HO Atlas layout...

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montanan

Whiskey Merchant
jdetray did bring up a very good point about the tracks having to be really clean when running a DCC locomotive. Is you know, I am a DC operator but I do have a few DCC locomotives and I have noticed that the DCC locomotives are extremely more sensitive to dirty track. I posted a video of some switching a few days ago and ran the train on tracks that hadn't been cleaned in quite a while and the DCC locomotive did have a couple of issues whereas when running a DC locomotive over the same tracks it was extremely smooth with no problems at all.
 

Yannis

Active Member
Hey Tony,

I hope that the dcc issues get sorted soon. As for the track plan changes, just check the s-curve on the right side of the layout that you plan to change (marked with red track) so that it doesnt cause any derailments with equipment that you might want to get in the future (passenger cars etc).
 

wombat457

Well-Known Member
Staff member
Glad that you finally can get trains running again. The change looks like it should help of you're running passenger cars.

You made a real good point, it's not a competition out there. Our model railroads are ours, and we all have different interests, model different eras and have different likes and dislikes. In a post by the IRON HORSEMAN, I realized that I have been building my layout for over 30 years, and it's still not done, and probably never will be. I have finally laid the last tracks, but will most likely go back and upgrade older parts of the layout using thing I have learned over the years using methods and skills I didn't have when the layout was started.
You also raise a very valid point Chet - our layouts are never done, especially the larger ones. As you said, once we get to a point where all of the "major work" is complete, it often becomes time to go back and start "upgrading" things based on newly found knowledge and experience. I expect to have this layouts fundamentals finished quite soon, but am sure that I will be going back over things I too did 12 months ago and try to improve on them.

I can tell you 100% that while I am happy, the Chief Engineer" is even happier - and that is a very good thing! I think now I have the layout working, I might even leave it as a DC layout. The Chief even said not to mess with it anymore now it is running so I may have just become a DC convert.

That being said, and with my luck, I think once I get it all running properly I'll just leave it :)

Hi Tony --

The derailing is hard to explain. The same locomotive running at the same speed ought to have an equal chance of derailing whether powered by DC or DCC, it seems to me.

Stopping and hesitating tells me there are places on the layout where the loco's wheels are not making good contact with the track. This could be dirty track or uneven track -- anything that would cause a loss of wheel-to-track contact.

When running DC, the loco's momentum carries it past the loss of contact, and the loco keeps going. A momentary loss of contact does not bring a DC loco to a stop. However, if I am correct, then speed is a factor. If a DC loco is moving very slowly then it, too, would stop at the "bad" spots.

With DCC, even a momentary loss of contact can be enough to stop the loco because the flow of data is interrupted. That's why so-called "keep alive" decoders and add-ons have been developed for DCC. These include capacitors onboard the loco to provide a continuous source of power to the decoder during a brief loss of contact with the rails.

A less expensive solution is to keep the rails and wheels squeaky clean. Even brand new from the box locos can often use a wheel cleaning.

- Jeff
Jeff,

Thank you for very clear and in plain english explanations. Everything you said actually makes sense to me, especially the reason for the hesitation in some places. I have been painstakingly trying to keep the track clean BUT forgot to consider whether or not it may uneven in those places. Time to take another look and see if that is the problem.

I also take your point re engines straight out of the box too. In hindsight, I recall someone saying that "some" manufacturers use some sort of cleaner or inhibitor on the wheels for shipping. I never thought about cleaning "new wheels" but will now.

I also like your solution to the problem - that definitely works for me :D

Hey Tony,

I hope that the dcc issues get sorted soon. As for the track plan changes, just check the s-curve on the right side of the layout that you plan to change (marked with red track) so that it doesnt cause any derailments with equipment that you might want to get in the future (passenger cars etc).
Yannis,

The "S Curve" (as shown) isn't as bad as it appears; although, I will run a Pullman Car around it to make sure there are no problems. Having the Wye Switch in there I think will help as well by taking out some of the "curve" so to speak and give longer cars the chance to "adapt". Well, it sounds good to me anyway :D
 
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Iron Horseman

Well-Known Member
Now with that being said. I am going to pose a question or two to you all - especially the DCC Guru's...

Why does everything run so well on DC, yet there are so many issues when running (trying to run) DCC?

This I do not understand. Regardless of whether it is DC or DCC all it is is power going from point A to point B. If DC power gets to point B without an issue, why doesn't DCC power do the same thing?

How is is that DCC engines will derail and stop and hesitate and mostly just not run period, yet DC engines have no problems on the very same track work and the very same wiring?

Why do old, not all that clean, DC engines run fairly well on the track when "BRAND NEW" (never been out of the box) DCC Engines wont run at all? This was the straw that broke the camels back by the way.

I cannot answer the first question because I have had not had the problems running DCC (or any command control system for that matter) which you have experienced.

The second question is that it does. It isn't a matter of the electric power getting to where it needs to be but what happens after it gets there.

Other than the derailment problem which I cannot imagine has anything to do with power, the third and fourth questions have the same answer. With DC there is one very easy to interpret command signal - the voltage. Likewise that command signal is feeding directly to the motor. When a loco experiences a millisecond interruption in power the command hasn't changed it is still the same voltage being applied directly to the motor. So the loco trundles on. With DCC, the command signal is very complex and it must be interpreted before some command is sent to the motor. To a computer micro processor a millisecond is ffffooooooorrrreeeeeevvvveeeeeerrrrr. The power interuption might even be long enough for it to shut down and have to re-boot so to speak. Even if not forced to re-start, when the signal is re-acquired the transmission could be in the middle of a command to another unit. If the bit sequence is just so, the microprocessor could interpret the signal wrong and even think it has been told to go full reverse. What it needs to do is just wait for the next full command and act, but once again in computer terms that could be another eternity. "What should I do with the motor while I wait," it asks itself! Even if it goes to the memory to re-execute the last full command received, that millisecond power outage could have corrupted that memory to say anything, even full stop. I always like to think of it as a small child who has lost their parents in a store and are in a panic. Run this way, run that way, cry out, yell, scream, flail hands in the air. etc. Just a few of those dirty spots can easily cause the locomotive stuttering as it works through all the decisions that have to be made. This is why the "keep alive" capacitors help so much. While the micro-processor in the decoder might not be getting a full signal, it can at least continue giving the motor the last full command received. Whether or not a given decoder is truly micro processor controlled or just a set of nand / nor gates it is still a digital circuit that has to reset after power interrupt and the same concept applies.
 

wombat457

Well-Known Member
Staff member
Thanks Guys, this stuff IS slowly sinking in and for me, that's a huge step forward. Appreciate all of your time and explanations, advice and so forth.

Chet,

You hit the nail on the head, especially with the last "S" :)
 

wombat457

Well-Known Member
Staff member
Suzie,

Hey nice to see you again. I may have to re-check my feeders for connectivity from the main bus and to the track, even though I am pretty sure they are all okay, and I do have one every 3' roughly.

The more I am hearing, the more I am starting to think that perhaps the digitrax was faulty. Now I am not blaming my tools as an excuse for anything that I may have done or not done BUT, it does seem strange, after what you have just said, that things are running nicely with just DC.

The decoders in the engines, a Bachmann, Athearn Genesis and a Walthers are all factory fitted so I don't know what they are or how good they are. Sorry, the Walthers is Soundtraxx Tsunami decoder but as for the others, I wouldn't have clue. I'd really like to take those three engines to another layout and see how they ran on it.

As you know though, I have never been all too happy with digitrax so I will give the NCE a try and if that is no better, after double checking everything, I don't think I will have an option other than going straight DC; unless, I can find someone local to come and take a look at things.
 

wombat457

Well-Known Member
Staff member
Afternoon all,

In my search for my NCE System (still missing in action) I ran across a couple of radius gauges (18 and 20 degree) I had forgotten that I had bought. Checked the curves on my track to discover that most of them are at least 20 degree. The only ones that aren't are the ones I am changing - and they will be changed to 20 degree curves making running everything I have more than possible.

I also hand ran my 3 Pullman Cars around the track and they ran the "current curves" without an issue. Only problem I did discover was with a couple of small sections of my scenery being too close to the track for them. Fixing that will only require a Razor Saw and a bit of ground cover :) All in all, things are looking good so far.

I am also expecting to receive my 4 Amtrak Cars this Friday or Saturday, along with new Peco Rail Joiners both standard and powered. Once I get them, the front section of the layout will be redone (20 degree radius) and the new siding will go in as well. Not notwithstanding any major issues, I should be up and running (at least in DC mode) by Sunday evening.

Once that is completed, it will be time to "clean everything up" and start getting some of the structures back in place. I AM getting excited about this now, or at least, again! :D
 

wombat457

Well-Known Member
Staff member
Major Update!

Afternoon Guys,

As you guys know, or might know, I bought an Amtrak F40 for an Amtrak train. According to Walthers, the 85' Amtrak cars would run on 18" radius track ... WRONG!

Anyway, as mentioned in an earlier post, I had 2 curves that were less than 18" and needed to be increased. This morning was taken up increasing those two curves from around 15" to now 20".

That exercise required the pulling up of 10' of track, including a Wye Switch, and re doing it all with new track as well as inserting a second Wye Switch for a siding. I am very happy to say that it all went in without an issue and, even though parts of that track work are still floating in the air, my DC loco's still run on it nicely and without issues.

On this occasion, I did not use insulated joiners nor did I do any solder work so everything came out cleanly. The biggest aid was the use of the 20" and 18" track radius gauges that ensured I would end up with smooth curves the right radius.

Anyway, here are a couple of (possibly not so good) pictures of what was done going from left to right:

Img_0058_zpsehpofqqt.jpg


Img_0059_zpsjrrowpuv.jpg


Img_0060_zpsbubpv4t0.jpg


You'll notice some "loose wiring", that will be connected as soon as I find my NCE System :)
 

Yannis

Active Member
Nice going Tony! The broader the better for the track curves. I am glad the re-work went fine with your tracks.
 

wombat457

Well-Known Member
Staff member
Thanks guys,

Now all I have to do is convince the "Chief" to let me redo "all" of the curves and increase all of them to 20" radius. That isn't going to be easy as she has already put her foot down about any more improvement :(
 

wombat457

Well-Known Member
Staff member
A quick update - while I haven't convinced the boss to let me pull up track to redo the radius, she does seem to be more flexible about that, especially as she now has her beloved Amtak Train which, I am gradually convincing her of, needs at least a 20" radius to run smoothly and properly.

Keeping that in mind then, another modification to the track plan and one that will (once again) improve the running of trains. You might recall that I was going to put in a spur line along the front edge of the layout, well after careful consideration I couldn't see any reason why I couldn't just extend the main "outer line" around to where the new Wye Switch is and, effectively, have about 85% of the layout double tracked. Even if I do that (which I will) I still think I will have room for a small siding, long enough to hold a couple of engines if nothing else.

I'll throw in a picture so you can see what I am talking about ...

Final%20Plan%202_zps8qihws6a.jpg


The Green is the new section of track and will have 20" radius curves, as does the red section. This new section will give the "old" outside main track close to a 24" radius curve which, when alls said and done, irrelevant as I have to run on the smallest radius.
 

wombat457

Well-Known Member
Staff member
Darn, what an interesting evening I have had.

I really need to thank Genetk44 for his help with the NCE System this evening. After spending about an hour on the phone with him, I can now honestly say that I understand it to the point of programming (successfully) loco cabin address's and being able to run more than one loco at a time. For the first time, I have two engines operating (albeit a little sluggishly due to dirty track) on the layout and that is a huge thrill for me.

Now it is time to get the new section of track completed and am now also thinking about redoing all the wiring - perhaps. A fresh start with a properly operating system.
 

wombat457

Well-Known Member
Staff member
Oh and here you go again.... I'm about to do the same thing all new from the bench up!
Gator, I wish I could do what you are doing, start from scratch! I know if I could do that, with the knowledge I have gained from you guys, I would make a lot of changes and make different things the focus.

To be honest, I now look at the room I have and can see ways of doing the track plan differently that would give me a larger radius for curves, albeit not much larger. As it is, I guess I don't have the luxury (if you like) to rip everything up and start again so I have to do what I can with what I have. The annoying thing to me is that if I could "fudge" another 2" or 3" in all directions, I could have a much better track plan with (perhaps) 24" radius curves.

I am looking forward to seeing your rebuild and good luck with it :)

Please post updates. I'M a 'first timer' and need all the pointers I can get! Thanks!
new guy, if there is anything that you need to know, want to know, just ask ... you will get all the help and advice you will need, regardless of what it is. The worse thing you can do is NOT ask a question, believe me - there are so many facets to this hobby and so many things that can go wrong that it wont take long to end up being up to your neck with problems if you don't ask questions, ANY questions.

I think I can speak for others, such as gator - the reason we pull our layouts apart and redo things, or start over is because there was something that could be improved in the layout, things that may have been able to have been done from the start but weren't for some reason.

Best advice I can give you (from the experience of not doing it) is to be patient, know what you want for the layout (point to point, looped, passenger runs, freight, switching, realistic operations etc etc etc) don't rush anything and plan everything down to the last nut and bolt (so to speak) before doing anything THEN, get opinions from the experience here, take that experience and advice and then start the physical work of building the layout. Then, double check everything as you go and continue to ask questions, even if only to get verification of what you are thinking.

Lastly, and to save confusion, when you ask a question - ask a specific question about one thing per post to ensure you get the answer you need and not be, or end up being, possibly confused by multiple answers to multiple questions in one post.

Remember, the ONLY DUMB QUESTION is the one NOT ASKED!
 
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