Fully automated, DC reversing loops

A

alasdair555

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I'm sure there are already posts on topics similar to this, but I'm struggling to find one that explains the options available clearly.

In summary I'm planning a simple single track reverse loop, the railway needs to be operated by young children, and we've got DC track feed.

As a result I can't expect them to stop/start and switch points in perfect sequence, so would prefer either an off the shelf solution, or a simple wired solution which requires little if any intervention!

This is my other post with mor detail on the overall track layout etc.

Many thanks in advance for all suggestions,

www.gscalecentral.net

Under 5s and G scale

Made some progress on the layout today, cut some supports for the railway from a chimney pot, but used up 2 angle grinder cutting disks in the process, so I'll need to wait a little while before I can do much more on that front. On the plus side the remainder of the line now has profiles, and so...
www.gscalecentral.net www.gscalecentral.net
 
alasdair555 said:
I'm sure there are already posts on topics similar to this, but I'm struggling to find one that explains the options available clearly.

In summary I'm planning a simple single track reverse loop, the railway needs to be operated by young children, and we've got DC track feed.

As a result I can't expect them to stop/start and switch points in perfect sequence, so would prefer either an off the shelf solution, or a simple wired solution which requires little if any intervention!

This is my other post with mor detail on the overall track layout etc.

Many thanks in advance for all suggestions,

www.gscalecentral.net

Under 5s and G scale

Made some progress on the layout today, cut some supports for the railway from a chimney pot, but used up 2 angle grinder cutting disks in the process, so I'll need to wait a little while before I can do much more on that front. On the plus side the remainder of the line now has profiles, and so...
www.gscalecentral.net www.gscalecentral.net
Click to expand...
I have had success using a Dallee Electronics TRAK DTLR #566 which enables “hands off” operation of a double-ended reverse loop line. I use spring switches for ultimate simplicity. The details @ the Dallee website show other options for switch control. Using additional diode controlled block sections, you can automatically run as many as 3 trains in sequence on this single track. As this device simply serves as a reliable sensor to change polarity, the dioded sections provide reliable control if multiple trains are desired. Or one train will go back and forth all day with no attention required.
 
LVT said:
I have had success using a Dallee Electronics TRAK DTLR #566 which enables “hands off” operation of a double-ended reverse loop line. I use spring switches for ultimate simplicity. The details @ the Dallee website show other options for switch control. Using additional diode controlled block sections, you can automatically run as many as 3 trains in sequence on this single track. As this device simply serves as a reliable sensor to change polarity, the dioded sections provide reliable control if multiple trains are desired. Or one train will go back and forth all day with no attention required.
Click to expand...
Thanks Arthur, appreciate the detail, the only issue is that I've got DC track power. I'm also not sure if this product is available in the UK?
 
alasdair555 said:
Thanks Arthur, appreciate the detail, the only issue is that I've got DC track power. I'm also not sure if this product is available in the UK?
Click to expand...
Alastair: I operate dc also, seems designed for it. It does require regulated 12 v d.c. for the operating system, for which they do sell a power unit which operates off low voltage a.c. They might ship to the U.K., but my guess it would be at a cost equal to or higher than the product itself. I know there are other manufacturers of current-sensing control devices elsewhere, but I don’t know if they duplicate this configuration. Hopefully some direction will follow from those aware of model railway control sources “over there”.
 
Dallee Electronics list Brandbright as the 'European' contact for their products.. :wondering:

However, Brandbright changed hands, not so long ago, so this might be historical, rather than the current situation?

PhilP.
 
I have a dumbell branch line on my railway. The loops at each end have sprung points so they always go the same way & are permanently connected to the controller. The central section is fed through a double pole changeover relay , a LGB signal with an auxiliary switch. This is operated by reed switches, one in each loop.
When a train enters the loop it always goes the same way, it operates the reed switch & reverses the polarity of the central section for its return journey.
Fully automatic & using standard LGB components.
 
You can do it with LGB EPL as well. The 10151 Reverse Loop Set is a set of Isolators that have a Diode that permite travel round a Loop, but one way only. With EPL Track Contacts and an Electric Point one can ensure that the point faces the right way when trains approach it from the main, another as the train approaches from the other way and the point will change again. One thing to remember with this method, as the train is in the reversing loop the current needs to be reverced, it can be done wile the train is moving and the train will carry on the same way.

this thread may help

forums.mylargescale.com

LGB reverse loop non-MTS setup

I know this subject has been discussed a lot but I'm having trouble setting up my first LGB 10151 T 10151K reverse loop. My LGB train enters the loop and crosses the "T" section and continues traveling until is hits the "K" section just before exiting the loop back through the switch track...
forums.mylargescale.com forums.mylargescale.com

this is the isolation recpverse loop product, though it is easy enough to make yourself with 4 diodes and 4 LGB Rail Isolators.

LGB 10151 Gauge G Reverse Loop Track Set, 2 each 150 mm / 5-7/8“ modellbahnshop-lippe.com

modellbahnshop-lippe.com - Online Shop for model trains and accessories - Märklin • PIKO • Roco • Trix • Fleischmann • ✓ Great offers ✓ Great selection ✓ Short delivery time ✓ Top service
www.modellbahnshop-lippe.com www.modellbahnshop-lippe.com
 
dunnyrail said:
You can do it with LGB EPL as well. The 10151 Reverse Loop Set is a set of Isolators that have a Diode that permite travel round a Loop, but one way only. With EPL Track Contacts and an Electric Point one can ensure that the point faces the right way when trains approach it from the main, another as the train approaches from the other way and the point will change again. One thing to remember with this method, as the train is in the reversing loop the current needs to be reverced, it can be done wile the train is moving and the train will carry on the same way.

this thread may help

forums.mylargescale.com

LGB reverse loop non-MTS setup

I know this subject has been discussed a lot but I'm having trouble setting up my first LGB 10151 T 10151K reverse loop. My LGB train enters the loop and crosses the "T" section and continues traveling until is hits the "K" section just before exiting the loop back through the switch track...
forums.mylargescale.com forums.mylargescale.com

this is the isolation recpverse loop product, though it is easy enough to make yourself with 4 diodes and 4 LGB Rail Isolators.

LGB 10151 Gauge G Reverse Loop Track Set, 2 each 150 mm / 5-7/8“ modellbahnshop-lippe.com

modellbahnshop-lippe.com - Online Shop for model trains and accessories - Märklin • PIKO • Roco • Trix • Fleischmann • ✓ Great offers ✓ Great selection ✓ Short delivery time ✓ Top service
www.modellbahnshop-lippe.com www.modellbahnshop-lippe.com
Click to expand...
The disadvantage of this is that the controller has to be reversed every time a train goes around the loop. Using the way that I suggest, using EPL components, the controller doesn't need to be touched.
 
dutchelm said:
The disadvantage of this is that the controller has to be reversed every time a train goes around the loop. Using the way that I suggest, using EPL components, the controller doesn't need to be touched.
Click to expand...
Ah that is so but the for the young ones the train goes in the opposite direction of the controller on the main line after each trip round the loop, horses for courses I reckon.
 
dutchelm said:
I have a dumbell branch line on my railway. The loops at each end have sprung points so they always go the same way & are permanently connected to the controller. The central section is fed through a double pole changeover relay , a LGB signal with an auxiliary switch. This is operated by reed switches, one in each loop.
When a train enters the loop it always goes the same way, it operates the reed switch & reverses the polarity of the central section for its return journey.
Fully automatic & using standard LGB components.
Click to expand...
Hi Dutchelm,

That sounds close to ideal, do you have the LGB component numbers so I can work out a parts list (and cost :( )
 
dunnyrail said:
Ah that is so but the for the young ones the train goes in the opposite direction of the controller on the main line after each trip round the loop, horses for courses I reckon.
Click to expand...
Hmm that could get confusing, we already have some issues with trains shooting off in the wrong direction. At present I can at least show them that the controller is configured in the correct direction. If it kep changing I'd have no one to blame! :)
 
Here's the easiest I ever came up with. I first used this on the distant stub track of a wye, facing me at right angles where the actual direction of travel is ambiguous, and it works brilliantly. the reversing switch is left alone and the loco simply enters the track selected by the points. I've adapted the idea to a reverse loop as well, where it's even simpler.

I think the main feature here is the gaps cut in the running rails opposite from the frog. or near enough. The idea is that all the confusion is contained on the switch track, which, once adapted, can be used in similar applications at another time.

You only need to throw the points at the throat to exit the loop. If you are troubled by the alternating direction of the controller's rev. switch, once your train is clear of the points simply throw them back to the way they were. See the sketch attached.
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This is one of Johnnychuffchuff's many track tricks.
 

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John Le Forestier said:
Here's the easiest I ever came up with. I first used this on the distant stub track of a wye, facing me at right angles where the actual direction of travel is ambiguous, and it works brilliantly. the reversing switch is left alone and the loco simply enters the track selected by the points. I've adapted the idea to a reverse loop as well, where it's even simpler.

I think the main feature here is the gaps cut in the running rails opposite from the frog. or near enough. The idea is that all the confusion is contained on the switch track, which, once adapted, can be used in similar applications at another time.

You only need to throw the points at the throat to exit the loop. If you are troubled by the alternating direction of the controller's rev. switch, once your train is clear of the points simply throw them back to the way they were. See the sketch attached.
View attachment 267707
This is one of Johnnychuffchuff's many track tricks.
Click to expand...
Thanks for this John.

Just a point I haven't mentioned yet which might be relevant, my points are AML with live frogs, does this make things simpler or more challenging?
 
It's simpler to see with live frogs, and operations will be more reliable as insulated frogs can cause certain problems. If it were an insulated frog both off rails would be connected anyway: follow the inner rail of the loop. It's all one rail. The whole circuit can be integrated into the track switch or 'points'' and so made portable. The only gaps you need are shown in the diagram. There is no problem. Just wire it like the diagram shows you. Look at it this way: what you are doing is drawing your mainline track power from either the left or right "side" of the loop.
 
John, there is no gap shown in the 2 rails from the frog. Unless the frog rails (the 2 short rails from the frog) are completely isolated (which they are not in LGB or Piko or Aristo or a live frog) you need gaps there...

This is because the frog rails will be tied to one or 2 of the stock rails. Also in most cases they are tied near the points.... therefore the "frog rails" will be fed from either or both of the stock rails which are powered from the relay...

short circuit. Just show gaps in both rails after the frog and you will be fine.

Greg
 
Gaps are needed in the closure rails if your metal flanges cause a short between stock and point rails. I understand this to be highly troublesome in DCC systems, momentarily bearable in DC systems, and unlikely in most proprietary pointwork.

A closure rail gap causes an unadapted point, with no additional contact or jumper added, to rely for power on contact with its stock rail, and this is highly problematic.

In my system here, all four rails from the frog have the same polarity. Their polarity is determined by the DPDT reversing switch on the controller. The new DPDT switch, connected to the throwbar of the points, controls the power from the loop to the to the running rails of the mainline. It simply aligns this power with the arm of the loop that the points lead to.

I set mine up so that in operation the front part of the loop accords with the direction indicated by the power pack and I recommend this choice. A train on the back part of the loop therefore will be going the opposite way, and as long as the points are aligned for the back track this will continue on down the main. The solution is simply to return the points into alignment with the front half of the loop.

The G gauge B'mann switch I first used for this had an insulated frog. It was one of the switches that matches B'mann's pressed steel tinplate track. These switches are made with cast metal rails that appear to be nickel-plated white metal. I used a small hacksaw to make my gaps in the running rails. The second project was in Sn42, using Triang HO/OO pointwork. This proprietary switch also had an insulated frog. Both switches had jumpers under the plastic of the frogs.

In practice all my gaps and all the wiring, including the basic power feed which, note well, must be fed to the reverse loop and not to the mainline, are integral with the switch, which makes for a very tidy, entirely portable, and extremely handy setup. I strongly suggest that if you are planning to adopt this scheme, plan to integrate all your wiring to the switch (UK points).

Thanks, everyone, for the attention you've given this.
 
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