Digitrax PM 42


Steven Tobias
 

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Kurt Konrath
 

You need to separate each district. 

Plastic joiners work but if rail is down you can use thin fiber disk in Dremel tool to cut a thin gap. 

This gap can be filled with styrene glued in place with CA and filed to profile of rail.  

It’s but one way to gap rails. 

You don’t have to pull track up to isolate rail districts. 

Kurt 


On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Blair
 

A jewelers saw, commonly used for cutting rail, will also do in a pinch, just be sure to go gently, or when the saw snags, as it will, you'll rip the rail out of the plastic ties.  If you don't own a Dremel, it's an expensive solution compared to a small saw.

Be sure to cut both rails to isolate districts.  You can't get away with just one cut, you need both cut.  And for reversing sections, the same thing applies.

Blair



On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Steven Tobias
 

Very helpful. Thank you. What is CA?

On Thu, Jan 13, 2022 at 11:24 PM Kurt Konrath via groups.io <kurt.konrath=yahoo.com@groups.io> wrote:
You need to separate each district. 

Plastic joiners work but if rail is down you can use thin fiber disk in Dremel tool to cut a thin gap. 

This gap can be filled with styrene glued in place with CA and filed to profile of rail.  

It’s but one way to gap rails. 

You don’t have to pull track up to isolate rail districts. 

Kurt 


On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Kurt Konrath
 

Generic name for Super Glue


On Jan 14, 2022, at 8:10 AM, Steven Tobias <srtobias29@...> wrote:

Very helpful. Thank you. What is CA?

On Thu, Jan 13, 2022 at 11:24 PM Kurt Konrath via groups.io <kurt.konrath=yahoo.com@groups.io> wrote:
You need to separate each district. 

Plastic joiners work but if rail is down you can use thin fiber disk in Dremel tool to cut a thin gap. 

This gap can be filled with styrene glued in place with CA and filed to profile of rail.  

It’s but one way to gap rails. 

You don’t have to pull track up to isolate rail districts. 

Kurt 


On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


whmvd
 

Cutting both rails or just the one ("common rail") is a choice rather than a necessity. It is worth researching, so that that choice is an informed one. Common rail works well for me. For a garden layout (such as I plan) every wire saved is important.

Wouter


On Fri, 14 Jan 2022 at 13:27, Blair <smithbr@...> wrote:

A jewelers saw, commonly used for cutting rail, will also do in a pinch, just be sure to go gently, or when the saw snags, as it will, you'll rip the rail out of the plastic ties.  If you don't own a Dremel, it's an expensive solution compared to a small saw.

Be sure to cut both rails to isolate districts.  You can't get away with just one cut, you need both cut.  And for reversing sections, the same thing applies.

Blair



On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Blair
 

Wouter
Strictly not necessary, I would agree, but three factors warrant it in most cases, to me.
1) there may come a day when another booster is added; it's not advisable to connect either rail in this case.
2) there may come a day when it becomes necessary to make a section autoreversing, and the gaps will be needed.
3) when diagnosing a short circuit, having isolated sections makes the number of possible problems fewer.
Agreed, there will always be use cases that speak to other alternatives, but exceptions-to-the-rule need context.  In your case, you know what your doing, and can make a value judgement.


On 2022-01-14 10:07, whmvd wrote:
Cutting both rails or just the one ("common rail") is a choice rather than a necessity. It is worth researching, so that that choice is an informed one. Common rail works well for me. For a garden layout (such as I plan) every wire saved is important.

Wouter

On Fri, 14 Jan 2022 at 13:27, Blair <smithbr@...> wrote:

A jewelers saw, commonly used for cutting rail, will also do in a pinch, just be sure to go gently, or when the saw snags, as it will, you'll rip the rail out of the plastic ties.  If you don't own a Dremel, it's an expensive solution compared to a small saw.

Be sure to cut both rails to isolate districts.  You can't get away with just one cut, you need both cut.  And for reversing sections, the same thing applies.

Blair



On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


JoAnn Donaldson
 

Yes, you need to separate the districts electrically. I have my version of the Red Oak Line and have a PM42. The front track is Zone 1. The hidden staging tracks is Zone 2, The hidden Staging tracks for the Interchange is Zone 3. The Interchange is Zone 4. The nice thing about using a PM42, is if you accidentally short a track, it does not shutdown the other Zones. I have plastic insulators on my layout. If you have already laid all your track, then you need to decided which tracks belong to which Zone and then use a dremnal tool to cut very small breaks in both rails. Cutting both rails is important.


On Friday, January 14, 2022, 09:26:32 AM CST, whmvd <vandoornw@...> wrote:


Cutting both rails or just the one ("common rail") is a choice rather than a necessity. It is worth researching, so that that choice is an informed one. Common rail works well for me. For a garden layout (such as I plan) every wire saved is important.

Wouter

On Fri, 14 Jan 2022 at 13:27, Blair <smithbr@...> wrote:

A jewelers saw, commonly used for cutting rail, will also do in a pinch, just be sure to go gently, or when the saw snags, as it will, you'll rip the rail out of the plastic ties.  If you don't own a Dremel, it's an expensive solution compared to a small saw.

Be sure to cut both rails to isolate districts.  You can't get away with just one cut, you need both cut.  And for reversing sections, the same thing applies.

Blair



On Jan 13, 2022, at 8:28 PM, Steven Tobias <srtobias29@...> wrote:

Hello

I am using the Digitrax PM 42 to segment 4 power sub-districts. 

My track is already down and soldered. I did not use plastic insulating rail joiners to separate the districts. Is this required? Do I have to pull up track?

Thanks,
Steven Tobias


Al Silverstein
 

Steven,
 
There are many different ways to isolate the rails of an electrical block.
 
The method I use is rather simple. I apply super glue to the rails at three ties on either side of where I want to cut the rails. I use the super glue not super glue gel.
 
After I am sure that the glue has dried I generally use a razor saw to cut the rails. I have also been know to use a Dremel jewelers cutting wheel. After I have cut the rails I apply another drop of super glue between the cut rails. When that has dried I use a 1200 grain sand paper to clean the top of the rails. The super glue between the cut rails insures no future short.
 
The above has been working great for me for over 20 years.
 
While it is not always necessary I always cut both sides of the rail at each rail at each end of an electrical block.
 
BTW I used the PM42 as a circuit breaker from the introduction of the PM4 until the introduction of the BXPA1 and BXP88.
 
Al Silverstein


Steven Tobias
 

Great info. Thank you. 

Steven Tobias

On Fri, Jan 14, 2022 at 2:56 PM Al Silverstein <alsilverstein@...> wrote:
Steven,
 
There are many different ways to isolate the rails of an electrical block.
 
The method I use is rather simple. I apply super glue to the rails at three ties on either side of where I want to cut the rails. I use the super glue not super glue gel.
 
After I am sure that the glue has dried I generally use a razor saw to cut the rails. I have also been know to use a Dremel jewelers cutting wheel. After I have cut the rails I apply another drop of super glue between the cut rails. When that has dried I use a 1200 grain sand paper to clean the top of the rails. The super glue between the cut rails insures no future short.
 
The above has been working great for me for over 20 years.
 
While it is not always necessary I always cut both sides of the rail at each rail at each end of an electrical block.
 
BTW I used the PM42 as a circuit breaker from the introduction of the PM4 until the introduction of the BXPA1 and BXP88.
 
Al Silverstein