Date   

Re: DCC Bus reversing question

Blair
 

oops.  I forgot, this list strips attachments.

See Sketch "loop schematic e.jpg" in the files.  It'll be there momentarily.

Blair

On 2021-08-18 18:00, Blair wrote:
Attached is a rudimentary sketch to illustrate my staging yard. (remember, there are two such, very similar).

You can see, I hope , how it makes sense to me to simply reverse the entire B/C loop section, and thereby avoid other complications.  I looked at using an AR for each approach, e.g. L to N, or even just M to N, and similarly Q or R to S; in each case, there are use cases where the reversing block thus created could have a train entering and leaving.  Only the crossover bottleneck presents a single, unambiguous reverse vs don't-reverse use case.

I think, on the whole, reversing the booster would be best, if only the booster fed only sections B and C.  However, given that I still have hopes of initially running both staging areas from one booster, as shown, that option is off the table, leaving me with only one - reverse using a DPDT relay dedicated to each staging yard, as shown.  I don't want to use an AR here, as an AR will be used for track section D, and it will be connected to B, forming the dreaded "adjacent AR" conundrum.

Blair







Re: DCC Bus reversing question

Blair
 

Attached is a rudimentary sketch to illustrate my staging yard. (remember, there are two such, very similar).

You can see, I hope , how it makes sense to me to simply reverse the entire B/C loop section, and thereby avoid other complications.  I looked at using an AR for each approach, e.g. L to N, or even just M to N, and similarly Q or R to S; in each case, there are use cases where the reversing block thus created could have a train entering and leaving.  Only the crossover bottleneck presents a single, unambiguous reverse vs don't-reverse use case.

I think, on the whole, reversing the booster would be best, if only the booster fed only sections B and C.  However, given that I still have hopes of initially running both staging areas from one booster, as shown, that option is off the table, leaving me with only one - reverse using a DPDT relay dedicated to each staging yard, as shown.  I don't want to use an AR here, as an AR will be used for track section D, and it will be connected to B, forming the dreaded "adjacent AR" conundrum.

Blair


Re: Block Detection for signalling and automation

Blair
 

Hi Tim

That's more along the lines of what I was looking for in an answer, thanks.

I was already planning on dealing with industry, interchange, and house tracks that way.  As for turnouts for automation, it's a good point - but really, the automation should be looking at least 1-2 blocks ahead of the train and aligning turnouts appropriately, unless there are extenuating circumstances.  If a turnout is in a block, it shouldn't need to be thrown once occupied.

Looks like someone's going to have to push some more $$$ in to the detection budget.  Ouch!  I think I'm heading for somewhere around 100 blocks; between the detection, and the reporting equipment, and JMRI, I'll be busy for a while.  Good thing it's a hobby!  I think I'll gap it all for future detection, even if I then incorporate multiple sections into one block initially. Easier to separate out and detect separately if needed.

Thanks again

Blair


Re: Block Detection for signalling and automation

Tim
 

Hi Blair;

It depends (don't you love that answer?) 

Turnouts for industry spurs and other similar connections to "track other than main track" do not need to be individually detected. The tracks they lead to should be gapped and not detected. You don't want a boxcar at the Joe's Widget Factory loading dock to trip the detector. 

Given that, it is good practice to make turnouts lined away from the main track force the block to show occupied. I do this by placing a 10k ohm resistor between the frog and the diverging stock rail. 

As far as turnouts at the ends of passing sidings, or at the end of double track, or crossovers between multiple track, it depends. For the signaling on my layout (ABS/APB) turnouts are part of the block they are adjacent to, depending on signal configuration at that location. For CTC, these turnouts are isolated. It seems like a good to isolate turnouts for automation so that you can prevent throwing them while occupied.

Tim Rumph
Lancaster, SC


Re: DCC Bus reversing question

Blair
 

Thanks for the generic DCC reversing how to, Jim; I'm sure it is well intentioned.  Doesn't address my question exactly, but others will benefit.

I have to reverse a large area of my layout(up to 16 trains); that area is driven by it's own booster, BUT I want multiple sub-sections protected by SS breakers.  Though each track of my staging can be shut off, the upshot is I could have up to 4 multi-unit trains running simultaneously in the yard and approaches.  I want those trains to proceed without a glitch when I change the alignment of the |X|, so the reversing needs to be solid state.  I also want the yard and the approach tracks on separate circuit breakers.  So I see my booster either reversing and feeding breakers, or feeding an autoreverser* which then feeds two or more breakers. 

Your description of your layout is similar, though smaller I expect, than my situation.

The autoreverser must be FASTER than the circuit breakers in order to reverse before they act, else it won't act.  If the short is sustained (i.e. not resolved by the AR), then I want the circuit breakers to act BEFORE the AR swaps the polarity again; I strongly suspect the AR actions will suppress the sensing of a short by the breakers, resetting their timing.  So I don't think this will work well - I expect it will flip-flip-flip ad nauseum. 

Alternatives:

- Reverse the Loconet Railsync signals, which you don't seem to like, but which I see no fundamental issue with, or

- use an autoreverser that can be triggered externally by the same signal driving the tortoises on the |X|.  I can't quite see how to do this using the PSX-AR, but I may just have misread the manual.  Comments appreciated if someone has done this.

I'm presently reviewing my staging plan to see if I can identify a single stretch of track in each approach that could be considered a "reversing section" of it's own, thus allowing the staging yard itself to be fixed polarity.  Problem is, if I do that, I think I can still have multiple trains entering/leaving it simultaneously, due to the layout, which wouldn't be acceptable.  These concerns are what resulted in my "flip-it-all based on one crossover state" approach.

Blair



On 2021-08-08 20:39, Jim Betz wrote:
Blair/Don ... and all,

  You don't need to re-invent the wheel.  DCC works just fine as designed.  DCC wiring - if
you follow Gartner's recommendations - is also easy and fool proof (if you follow them
correctly).  Specific responses:

  1) No you don't need to swap railsync wires - and you shouldn't do so.
  2) Yes, you can use some kind of physical switch to "rewire" reversing
       sections.  Most guys like the automated aspect of a Reversing DCC
       circuit breaker.
  3) The best (in my opinion) DCC circuit breakers are the PSX series.  They
       work and work well.  They were designed with sound in mind.  They are
       electronic (which makes them fast).  Yes, they cost a bit more than 
       other brands of DCC circuit breaker - yes, they are worth it.
  4) A reversing section should not be up against another reversing section if
      you are using DCC circuit breakers.  They end up trying to out guess each
      other - and that competition usually goes on forever.  You can, with some
      breakers, set a different trip speed to prevent this ... but it is better to not
      have two reversing sections next to each other.  This is almost always
      possible thru careful selection of where your breaker boundaries are.
  5) A reversing section should be "longer than the longest train you will
      ever run thru it".  It does not have to be "the entire loop" - but most guys
      will set it up that way and it's usually easier.  Another way to say this one
      is "you don't want both ends of the train - or two trains at once - crossing
      the reversing section".  Again, the breaker gets confused and, in this case,
      ends up competing with itself.

  Reversing breakers work like this:

  a) Situation normal.
  b) A short occurs.
  c) The breaker -temporarily- tries reversing the polarity of the reversing
      section.
  d) If that works it leaves it alone and the train continues to run.
  e) If it didn't work then you have an "actual short" and the breaker goes
      into "there's a short" status.
  f) Most modern DCC circuit breakers also have an automated Retry.
     They will wait a second or two and then retest to see if the short is
     still there - this is what allows you to throw the switch and "clear the
     short".

  On my layout I have just one reversing section - it is the huge loop in
staging - the staging is 5 tracks wide and 3 trains long.  All trains enter
(and exit) staging thru just one track that goes to a switch.  All of the
track past that switch is both Staging and the reversing loop.  I have it
wired with just one circuit breaker.  If it ends up that there are too many
trains in staging (amp draw too high) I will cut the power to some of the
tracks (the ones that the turnouts make "unavailable".
                                                                                                - Jim

  


Block Detection for signalling and automation

Blair
 

Hi Folks

When blocking a section of track for signalling and automation, is it necessary to isolate and detect each turnout, or can the turnout be part of the approach block?  I can see how it might be 'better' to detect the turnout, but does it actually matter when it comes down to it?  I'm thinking the answer is 'isolate them for signalling, but don't bother for automation', but I'd like confirmation.  If I don't need separate detection in staging, it saves me a significant number of detection circuits.

Thanks

Blair Smith


Re: magnet wire

Craig Zeni
 

I use it regularly on the surface mount style LEDs.

Craig Zeni
Cary, NC
Despatched from my infernal Android

On Tue, Aug 17, 2021, 11:25 Richard Neil via groups.io <rneilphoto=aol.com@groups.io> wrote:
I just wondered why I don't see/hear questions about using magnet wire.  Are there reasons to avoid such wire or is it a matter of convenience in handling or some other factors??


magnet wire

Richard Neil
 

I just wondered why I don't see/hear questions about using magnet wire.  Are there reasons to avoid such wire or is it a matter of convenience in handling or some other factors??


Re: Isolated/Dead Frogs

D B
 

Gary,
You’re quite welcome. That’s what this list serve is for!
Bill D


Re: Isolated/Dead Frogs

Gary Chudzinski
 

Thanks Bill D for your response! Not being that familiar with HO products, I found the Shinohara double crossover configuration quite interesting with respect to Subject topic. I suspect later locomotive products with DCCC installed do in fact include some type of current keeper. I also suspect with the lesser power required for HO locos, the size of that component does not need to be as large as the larger scale S and O locos.   Gary Chudzinski


Re: Isolated/Dead Frogs

D B
 

Gary,

I have been reinstalling my entire track — long story — with Peco track and turnouts. I had wired my turnouts with jumpers to directly power the turnout rails (the moving parts — eliminating reliance on contact with the powered rails at the turn-out end), and planned to power the frogs through my switch machines. None of the switch machines have been installed yet.

In running test engines to be sure that re-installed segments of track and the turnouts were installed properly (and wouldn’t result in derailments that had plagued the original layout), I found that my engines ran well through all the turnouts even though the frogs were not yet powered. I believe this could be attributable to keep alives becoming “standard” on most modern engines from better manufacturers. Mine are from MTH and BLI.

On the other hand, the steam locos in question were fairly large (an understatement), including an MTH N&W “J” (4-8-4) and a BLI N&W “A” (2-6-6-4). Interestingly, I did not experience any issues with an older Bachman DC steam loco (a Mikado) that was converted to DCC (I’m not aware of whether the decoder that my local hobby shop installed included a keep alive capacitor).

In any event, I’m going to defer powering my frogs for now.

If you can use size 6 turnouts, Peco makes a new turnout that is terrific. I think it’s called a “Unifrog”. Greatly reduced frog length and powered (hard wired) moving rail components that eliminate need for jumpers. Currently only available in No. 6 turnouts.

Bill D
N&W Steam Only


Re: Building a yard ladder -Slightly Off-Topic?

Allan AE2V
 

As noted, this topic is 'off topic."  The original question has been answered.  Let's wrap it up and then I will delete the thread.

Thank you

Allan Gartner
Wiring for DCC


Re: T-25 Wire Staplers

Mel Chase
 

Several years ago a member of one of the io groups posted using a stapler to tie down wiring.  What a great idea it replaced all my other methods.  Adding a piece of .080 styrene to the bottom of the stapler near the head will prevent the staple from completely seating.   This will maintain a space for a nylon zip tie or even a bread bag tie.  First thing is to put the staple where needed and parallel with the wire.  Slide the zip tie, etc through the staple and wire and cinch up.  Leave a loop if all that is needed is holding the wire out of the way like a switch machine actuator/throw arm or string more wires at a later time.  Very easy and cost effective.  Mel


Re: Building a yard ladder -Slightly Off-Topic?

PennsyNut
 
Edited

True but to an extent. Look at all the proto yards that don't follow that rule. Especially when its a hump yard with the turnouts thrown by the tower operator. Or am I wrong? Sorry this is off topic, but I had to comment.
Morgan Bilbo, DCC since 8/18. Model PRR 1952.


Re: DCC Bus reversing question

Don Vollrath
 

However to answer the original question…
You SHOULD be able to wire up an auto-reverser from DCC mains (or use an auto-reversing booster) to feed several PSX (or other brand) electronic circuit breakers that feed several CB protected districts inside a common reversing loop/section. Just make sure each of the circuit breakers react faster than the auto-reversing controller and that there is an initial section of track at both sides of the single AR loops district entrance wired before any CB protected track.
However I’m not sure you would want to do that as the troublesome areas will be at the turnouts and it sounds like costly non-effective overkill.

DonV


Re: Building a yard ladder -Slightly Off-Topic?

Scott H. Haycock
 

Prototype yard throats, as much as possible, were designed so all the switch stands were on the same side of the lead for personnel safety. The switcher would be 'faced' so that the engineer could see the ground crew operating the switch stands. 

Scott Haycock
Modeling Tarheel country in the Land of Enchantm
ent

On 08/08/2021 4:07 PM ROBERT HULTMAN <hultman@...> wrote:
 
 
 
Assuming the diverging tracks from the ladder turnouts run parallel to each other, the amount of straight track between one turnout's frog & the subsequent turnout's point rails would depend on the distance between track centers.  In the US, back in the earlier days, maybe 40s-50s, the yard tracks were probably 13' on center, more modern yard design probably widens out the track center-to-center distance more than 13'.
 
Bob Hultman in Brentwood TN
 
On Sunday, August 8, 2021, 01:33:04 PM CDT, <alynmar@...> wrote:
 
When building a yard ladder is it acceptable to place your turnouts end to end or should there be some track in between the turnouts, if so what would the recommended track length be in OO scale?     Thank you for any suggestions.

Alan


Re: Bachman DCC EZ track turnouts

Joseph A. Correro, Jr.
 

Thank you, Glenn!




"Life is not measured by the number of breaths we take, but by the moments that take our breath away!"


On Sun, Aug 8, 2021 at 5:58 PM Glenn <ghazel@...> wrote:
I don't think its possible. I think Bachmann turnouts draw power from the track.
-----Original Message-----
From: <w4dccqa@groups.io>
Sent: Aug 8, 2021 5:10 PM
To: <w4dccqa@groups.io>
Subject: [w4dccqa] Bachman DCC EZ track turnouts

I couldn't get anything from Bachmann regarding how to wire its DCC Onboard turnouts to my bus. Can anyone help me? Thank you!








Re: DCC Bus reversing question

Jim Betz
 

Blair/Don ... and all,

  You don't need to re-invent the wheel.  DCC works just fine as designed.  DCC wiring - if
you follow Gartner's recommendations - is also easy and fool proof (if you follow them
correctly).  Specific responses:

  1) No you don't need to swap railsync wires - and you shouldn't do so.
  2) Yes, you can use some kind of physical switch to "rewire" reversing
       sections.  Most guys like the automated aspect of a Reversing DCC
       circuit breaker.
  3) The best (in my opinion) DCC circuit breakers are the PSX series.  They
       work and work well.  They were designed with sound in mind.  They are
       electronic (which makes them fast).  Yes, they cost a bit more than 
       other brands of DCC circuit breaker - yes, they are worth it.
  4) A reversing section should not be up against another reversing section if
      you are using DCC circuit breakers.  They end up trying to out guess each
      other - and that competition usually goes on forever.  You can, with some
      breakers, set a different trip speed to prevent this ... but it is better to not
      have two reversing sections next to each other.  This is almost always
      possible thru careful selection of where your breaker boundaries are.
  5) A reversing section should be "longer than the longest train you will
      ever run thru it".  It does not have to be "the entire loop" - but most guys
      will set it up that way and it's usually easier.  Another way to say this one
      is "you don't want both ends of the train - or two trains at once - crossing
      the reversing section".  Again, the breaker gets confused and, in this case,
      ends up competing with itself.

  Reversing breakers work like this:

  a) Situation normal.
  b) A short occurs.
  c) The breaker -temporarily- tries reversing the polarity of the reversing
      section.
  d) If that works it leaves it alone and the train continues to run.
  e) If it didn't work then you have an "actual short" and the breaker goes
      into "there's a short" status.
  f) Most modern DCC circuit breakers also have an automated Retry.
     They will wait a second or two and then retest to see if the short is
     still there - this is what allows you to throw the switch and "clear the
     short".

  On my layout I have just one reversing section - it is the huge loop in
staging - the staging is 5 tracks wide and 3 trains long.  All trains enter
(and exit) staging thru just one track that goes to a switch.  All of the
track past that switch is both Staging and the reversing loop.  I have it
wired with just one circuit breaker.  If it ends up that there are too many
trains in staging (amp draw too high) I will cut the power to some of the
tracks (the ones that the turnouts make "unavailable".
                                                                                                - Jim

  


Building a yard ladder -Slightly Off-Topic?

ROBERT HULTMAN
 

Assuming the diverging tracks from the ladder turnouts run parallel to each other, the amount of straight track between one turnout's frog & the subsequent turnout's point rails would depend on the distance between track centers.  In the US, back in the earlier days, maybe 40s-50s, the yard tracks were probably 13' on center, more modern yard design probably widens out the track center-to-center distance more than 13'.

Bob Hultman in Brentwood TN

On Sunday, August 8, 2021, 01:33:04 PM CDT, <alynmar@...> wrote:

When building a yard ladder is it acceptable to place your turnouts end to end or should there be some track in between the turnouts, if so what would the recommended track length be in OO scale?     Thank you for any suggestions.

Alan


Re: T-25 Wire Staplers

Glenn
 

Hold the stapler so the bottom rests flat on the wire and not on an angle. That way the hammer of the stapler will not touch the wires.

-----Original Message-----
From: <w4dccqa@groups.io>
Sent: Aug 8, 2021 4:47 PM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] T-25 Wire Staplers


 
Ken,
If you lighten the pressure on the stapler it will penetrate less. It takes very little practice and you can test with a piece of scrap. If you want a piece of plastic between, put a piece of tape on the wire.
jd
 
On Sunday, August 8, 2021, 12:26:58 PM EDT, Ken Harstine <kharstin@...> wrote:
 
 
I am not seeing any T-25 staples with plastic to prevent shorting if the metal breaks through the insulation.  As long as only one wire is run under them it is not a problem but it seems like it is asking for a problem if two wires run under one staple.  Plastic insulation deforms under pressure and it seems like it would might break through the insulation on occasion and with enough time.

Regards,
Ken Harstine

 

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