Topics

PSX-AR Installation Query

John Cahill
 

I have been adding a large extension to my layout (DCC HO) which sits between what were independent and unconnected High level and Low level loops with great each having a station and fiddle yard. I have created two Wyes, one above the other and both double track, with a very complex point system to allow any train from the new section cross onto any track on both levels of the original layout. However complex pointwork takes a lot of space and I now find I am constrained by one of the stipulations regarding auto-reversers in tray the AR section should be longer than the longest train. 

one one end of the new module, a long length of track leads into the Wye so no problem with that side. However on the second level Wye, there simply isn’t enough length to achieve a satisfactory length. Then, reading the PSX-AR Instructions hoping for inspiration I read on p.7 Section E Notes, that it is possible to use a short length of track provided one cuts ADDITIONAL gaps inside the AR gaps longer than any bogies which would be used on this AR section. My problem is that it doesn’t say (that I can see) how to wire these new sections. I would be grateful if anyone can illuminate my darkness in this as I don’t see another solution to my space constraints. 

Thanks in advance 
John Cahill 

mgj21932
 

John,
I am a novice at DCC and haven’t found an explanation for the limitation you describe regarding the length of an AR segment needing to be longer than the longest train.  I’ve read that too, but haven’t seen an explanation for why.  Do you know?  
Bill


On Jan 20, 2020, at 8:53 AM, John Cahill <johncahill25@...> wrote:



I have been adding a large extension to my layout (DCC HO) which sits between what were independent and unconnected High level and Low level loops with great each having a station and fiddle yard. I have created two Wyes, one above the other and both double track, with a very complex point system to allow any train from the new section cross onto any track on both levels of the original layout. However complex pointwork takes a lot of space and I now find I am constrained by one of the stipulations regarding auto-reversers in tray the AR section should be longer than the longest train. 

one one end of the new module, a long length of track leads into the Wye so no problem with that side. However on the second level Wye, there simply isn’t enough length to achieve a satisfactory length. Then, reading the PSX-AR Instructions hoping for inspiration I read on p.7 Section E Notes, that it is possible to use a short length of track provided one cuts ADDITIONAL gaps inside the AR gaps longer than any bogies which would be used on this AR section. My problem is that it doesn’t say (that I can see) how to wire these new sections. I would be grateful if anyone can illuminate my darkness in this as I don’t see another solution to my space constraints. 

Thanks in advance 
John Cahill 

David Klemm
 

Bill,

Because you can’t have the train across 2 sections and trying to go in to a 3rd. There would be no way for the PSX-AR to flip to the correct polarity. 

Sometimes it helps to draw these out using a red pen for one rail and black for the other. Then you can see the fight that will occur. 

David Klemm
11 PRO Max


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of mgj21932 via Groups.Io <mgj21932@...>
Sent: Monday, January 20, 2020 8:00:55 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] PSX-AR Installation Query
 
John,
I am a novice at DCC and haven’t found an explanation for the limitation you describe regarding the length of an AR segment needing to be longer than the longest train.  I’ve read that too, but haven’t seen an explanation for why.  Do you know?  
Bill


On Jan 20, 2020, at 8:53 AM, John Cahill <johncahill25@...> wrote:



I have been adding a large extension to my layout (DCC HO) which sits between what were independent and unconnected High level and Low level loops with great each having a station and fiddle yard. I have created two Wyes, one above the other and both double track, with a very complex point system to allow any train from the new section cross onto any track on both levels of the original layout. However complex pointwork takes a lot of space and I now find I am constrained by one of the stipulations regarding auto-reversers in tray the AR section should be longer than the longest train. 

one one end of the new module, a long length of track leads into the Wye so no problem with that side. However on the second level Wye, there simply isn’t enough length to achieve a satisfactory length. Then, reading the PSX-AR Instructions hoping for inspiration I read on p.7 Section E Notes, that it is possible to use a short length of track provided one cuts ADDITIONAL gaps inside the AR gaps longer than any bogies which would be used on this AR section. My problem is that it doesn’t say (that I can see) how to wire these new sections. I would be grateful if anyone can illuminate my darkness in this as I don’t see another solution to my space constraints. 

Thanks in advance 
John Cahill 

John Cahill
 

My assumption is that it will not confuse the AR unit by each lit coach or other powered wagon from constantly sending a shorted gap message as the wheels cross the gap between. Hence the point about the new section being longer than any bogie.
John

mgj21932
 

David,

Thanks for the advice   I am using Tam Valley juicers as AR devices and in principle they should work the same.  Unless I’m mistaken, however, the only thing that should count for purposes of switching polarity is the length of the locomotive and tender UNLESS a subsequent car also draws power from the rails, e.g., a lighted passenger car or caboose.  Otherwise, as long as the passenger or freight cars are electrically isolated from the locomotive and draw no power from the track, they should have no effect on polarity and effectively be neutral as far as synchronizing polarity is concerned once the loc travels from section 1 into the reversing section 2 or out of 2 into 3 where all are reversing sections wired with AR controls and appropriate circuit breaker protection.  
Maybe the exception noted for cars drawing power for lighting is the reason for the “rule” as a safety precaution.  But otherwise I don’t understand why the rule would exist.  Lots of experience in the real world where rules of convenience are driven by the exception; and I suspect this is another example of that.  
Bill
P.S.  My degree in Chemistry is not very helpful in dealing with this electric wiring stuff! 😆


On Jan 20, 2020, at 9:24 AM, David Klemm <davidklemm7511@...> wrote:


Bill,

Because you can’t have the train across 2 sections and trying to go in to a 3rd. There would be no way for the PSX-AR to flip to the correct polarity. 

Sometimes it helps to draw these out using a red pen for one rail and black for the other. Then you can see the fight that will occur. 

David Klemm
11 PRO Max

From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of mgj21932 via Groups.Io <mgj21932@...>
Sent: Monday, January 20, 2020 8:00:55 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] PSX-AR Installation Query
 
John,
I am a novice at DCC and haven’t found an explanation for the limitation you describe regarding the length of an AR segment needing to be longer than the longest train.  I’ve read that too, but haven’t seen an explanation for why.  Do you know?  
Bill


On Jan 20, 2020, at 8:53 AM, John Cahill <johncahill25@...> wrote:



I have been adding a large extension to my layout (DCC HO) which sits between what were independent and unconnected High level and Low level loops with great each having a station and fiddle yard. I have created two Wyes, one above the other and both double track, with a very complex point system to allow any train from the new section cross onto any track on both levels of the original layout. However complex pointwork takes a lot of space and I now find I am constrained by one of the stipulations regarding auto-reversers in tray the AR section should be longer than the longest train. 

one one end of the new module, a long length of track leads into the Wye so no problem with that side. However on the second level Wye, there simply isn’t enough length to achieve a satisfactory length. Then, reading the PSX-AR Instructions hoping for inspiration I read on p.7 Section E Notes, that it is possible to use a short length of track provided one cuts ADDITIONAL gaps inside the AR gaps longer than any bogies which would be used on this AR section. My problem is that it doesn’t say (that I can see) how to wire these new sections. I would be grateful if anyone can illuminate my darkness in this as I don’t see another solution to my space constraints. 

Thanks in advance 
John Cahill 

mgj21932
 

John,
Thanks.  See my email to Dave.  I think we are on the same wave length. 
Bill


On Jan 20, 2020, at 9:25 AM, John Cahill <johncahill25@...> wrote:

My assumption is that it will not confuse the AR unit by each lit coach or other powered wagon from constantly sending a shorted gap message as the wheels cross the gap between. Hence the point about the new section being longer than any bogie.
John

Carl
 

Hello David:

If a car has metal wheel sets just the truck crossing the gap can cause a short. And if the car has a metal frame and metal wheels, the short can last longer. Back in the day even metal couplers could cause a short from one car to an other car. ( I have trouble with my metal Kadee couplers shorting to the center rail. )

So why fight the rule?

Also you might rethink what should be the reversing section. On Jim's layout we have three reversing sections, but if we were to rewire we could do it with two with no track changes.

Carl.


Pete
 

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses the polarity gap will cause the Auto Reverser to switch the polarity if there is a difference, so if your loco hits a second gap before the whole train is through that section, the loco will switch the polarity again and then  the wheels of the cars behind that cross the first gap will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but I'm following the advice that was given to me as it makes sense.
Pete

mgj21932
 

Thanks Carl. 
Your answer to “David” I believe was directed to me. 
Good advice.  Not going to fight the rule but trying to understand it.  
Bill


On Jan 20, 2020, at 2:53 PM, Carl <carl.blum@...> wrote:



Hello David:

If a car has metal wheel sets just the truck crossing the gap can cause a short. And if the car has a metal frame and metal wheels, the short can last longer. Back in the day even metal couplers could cause a short from one car to an other car. ( I have trouble with my metal Kadee couplers shorting to the center rail. )

So why fight the rule?

Also you might rethink what should be the reversing section. On Jim's layout we have three reversing sections, but if we were to rewire we could do it with two with no track changes.

Carl.


mgj21932
 

Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io <Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses the polarity gap will cause the Auto Reverser to switch the polarity if there is a difference, so if your loco hits a second gap before the whole train is through that section, the loco will switch the polarity again and then  the wheels of the cars behind that cross the first gap will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but I'm following the advice that was given to me as it makes sense.
Pete

Chuck
 

To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc=yahoo.com@groups.io> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete

John Cahill
 

Thanks for all your replies so far.  I get the requirement for the AR section being longer than the longest train.  However, what I'm struggling with is the note in the DCC Specialties PSX-AR (see original posting above) stating that it IS possible to have a shorter section PROVIDED a second set of isolating cuts are made at each end of the AR section.  This means, if my understanding is correct, that there are now 3 sections, the original (now middle) AR and one at each end of that original AR.  I can't figure whether these are wired through separate PSX-AR's or in some other way.  Can anyone help me with this one please?
John


On Mon, Jan 20, 2020 at 8:03 PM mgj21932 via Groups.Io <mgj21932=yahoo.com@groups.io> wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io <Kayakerpc=yahoo.com@groups.io> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses the polarity gap will cause the Auto Reverser to switch the polarity if there is a difference, so if your loco hits a second gap before the whole train is through that section, the loco will switch the polarity again and then  the wheels of the cars behind that cross the first gap will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but I'm following the advice that was given to me as it makes sense.
Pete

mgj21932
 

Nice idea.

On Jan 20, 2020, at 8:03 PM, Chuck <railfan@...> wrote:

To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete. Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc=yahoo.com@groups.io> wrote:

As it was explained to me...
If you are running metal wheels, every pair of wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete


Carl
 

Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      



John Cahill
 

But how does the loco drive across this 5cm unpowered gap?

Best Regards,
John

On 21 Jan 2020, at 02:55, Carl <carl.blum@...> wrote:



Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      


whmvd
 

That seems the only sensible explanation, but the fact remains that it won't help
- for wagons/carriages that have current pickups for lighting from more than one truck (or from all axles)
- for train configurations of critical length that contain a pull and a push unit
- power pickup for engines that are already marginal on pickup in the first place.
What happens is that the gaps are artificially made into very large gaps. A usable idea if the above does not pose a problem.

Wouter


On Tue, 21 Jan 2020 at 02:55, Carl <carl.blum@...> wrote:

Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      

    

whmvd
 

John,

By having a wheelbase larger than 5 cm.

Wouter


On Tue, 21 Jan 2020 at 10:37, John Cahill <johncahill25@...> wrote:
But how does the loco drive across this 5cm unpowered gap?

Best Regards,
John

On 21 Jan 2020, at 02:55, Carl <carl.blum@...> wrote:



Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      

    

John Cahill
 

Seems obvious when you put it that way, Wouter! I’m going to go with that because I think I’ve been overthinking it and missing the point (no pun intended). Thanks all for your helpful responses!

Best Regards,
John

On 21 Jan 2020, at 14:24, whmvd <vandoornw@...> wrote:


John,

By having a wheelbase larger than 5 cm.

Wouter

On Tue, 21 Jan 2020 at 10:37, John Cahill <johncahill25@...> wrote:
But how does the loco drive across this 5cm unpowered gap?

Best Regards,
John

On 21 Jan 2020, at 02:55, Carl <carl.blum@...> wrote:



Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      

    

whmvd
 

A bit too obvious, slick and facile I'm afraid. There are a few gotchas. First: wheelbase is one thing, but it's all about *powered* axles, i.e. they all must have power pick-ups. And if you find you have engines with asymmetrical power pickups (some steam engines have pick-ups on one track only, and the (mechanically and electrically) coupled tender picks up from the other rail) then expect Big Trouble.

I honestly think you're way better off finding a way to get the section length required by the theory instead of mucking about with kludges. Wyes can sometimes be seen in surprisingly different ways for purposes of cutting the rails for an auto-reverser. You might put a picture of the plan, with the proposed gaps, in the photo area of this group.

Wouter

On Tue, 21 Jan 2020 at 20:32, John Cahill <johncahill25@...> wrote:
Seems obvious when you put it that way, Wouter! I’m going to go with that because I think I’ve been overthinking it and missing the point (no pun intended). Thanks all for your helpful responses!

Best Regards,
John

On 21 Jan 2020, at 14:24, whmvd <vandoornw@...> wrote:


John,

By having a wheelbase larger than 5 cm.

Wouter

On Tue, 21 Jan 2020 at 10:37, John Cahill <johncahill25@...> wrote:
But how does the loco drive across this 5cm unpowered gap?

Best Regards,
John

On 21 Jan 2020, at 02:55, Carl <carl.blum@...> wrote:



Hi Gang:

I think the suggestion is to have a short section of insulated and unpowered track, say 5cm. That way the two wheel of one truck can't connect the powered sections.

Carl.

On 1/20/2020 3:33 PM, Chuck wrote:
To avoid the metal wheel problem, simply glue a piece of styrene into
the gap and when dry sand or file to match the rail. The wheels will no
longer contact both rails at the same time.

Chuck

On 2020-01-20 3:03 p.m., mgj21932 via Groups.Io wrote:
Pete.  Your metal wheels explanation makes absolute sense. Thanks
Bill


On Jan 20, 2020, at 2:58 PM, Pete via Groups.Io
<Kayakerpc@...> wrote:

As it was explained to me...
If you are running metal wheels, every pair of  wheels that crosses
the polarity gap will cause the Auto Reverser to switch the polarity
if there is a difference, so if your loco hits a second gap before the
whole train is through that section, the loco will switch the polarity
again and then  the wheels of the cars behind that cross the first gap
will switch the polarity again before the whole train is through
Your AR will be flipping back and forth as each set of wheels hit the
two gaps.
I hope I interpreted this correctly as I am new to DCC wiring too, but
I'm following the advice that was given to me as it makes sense.
Pete 

      

    

John Cahill
 

OK Wouter, I've opened a file called "PSx-AR Problem" and added 4 files showing a large part of the track plan and blow-ups of the two Wyes which sit virtually one above the other.  The drawing was done in AnyRail6 and pasted into Word as screenshots, so I hope you can read them. 

As to what locos run on the layout, a mixture of all they types you describe by Fleischmann, Roco, Piko, Marklin/Hamo and Rivarossi, mixed steam and diesel and all with various wheel and pick-up/power transmission arrangements.  Coaches are all fitted with lights, pick ups on opposite ends and feeding a flicker-free capacitor through a rectifier into LED Striplights.

Any feedback or questions welcome!
John