Software Tools
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The LGB 55085 or Massoth 8157001 is better, as it does not rely on a momentary short-circuit being created to activate the polarity switch.
R3 reverse loop
- Thread starter gscalerookie
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The LGB 55085 or Massoth 8157001 is better, as it does not rely on a momentary short-circuit being created to activate the polarity switch.
AlanL
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Reverse loops naturally create a short circuit. You therefore need to isolate both of the rails of the reverse loop This reverse loop has to be long enough that there is no conflict with power pick ups at both the front of the train and the rear as Gizzy explained. Coaches and wagons with lighting can also cause problems so generally the reverse loop should be longer than your whole train. If it is just a loco that uses the power then the length of the reverse loop is irrelevant but who knows in the future what you may be running?
Then to drive through the reverse loop, the power supply has to be reversed. In the LGB diagram that you attatched it uses DPDT switches but that is outdated now. It is easy with DCC by installing a reverse loop module that automatically detects the wrong polarity and reverses the supply for a seamless operation. Early reverse loop detectors were triggered by the short circuit but the latest versions as suggested by Software Tools above are better. Reverse loop modules are available from various DCC manufacturers but you will need one that is large scale capable.
Alan
As mentioned reverse loops need some sort of device to change the polarity in the loop itself. DCC is the easiest with a Massoth reverse loop module, this comes with 4 isolating rail clamps that can be used to mount the wires, fitted to the point that leads to the loop is desirable.
But if that is not the choice as line analogue not DCC, then the simplest solution is again to have 4 isolation joints at the points with a DPDT switch operated by the point to reverse the polarity in the loop whilst the train is stopped, then restart the train in the opposite direction and all is well as the train will run in reverse but exit the loop at the other end.
The diagram below was originally prepared tor a Wye (triangle) the dotted lines show how it works with a loop. DPDT can be an LGB motor auxiliary switch with connection from before the loop for power and revised polarity to the loop.
Note the wiring will also work for DCC, just reverse the point whilst train traversing the loop and no other changes required.
But if that is not the choice as line analogue not DCC, then the simplest solution is again to have 4 isolation joints at the points with a DPDT switch operated by the point to reverse the polarity in the loop whilst the train is stopped, then restart the train in the opposite direction and all is well as the train will run in reverse but exit the loop at the other end.
The diagram below was originally prepared tor a Wye (triangle) the dotted lines show how it works with a loop. DPDT can be an LGB motor auxiliary switch with connection from before the loop for power and revised polarity to the loop.
Note the wiring will also work for DCC, just reverse the point whilst train traversing the loop and no other changes required.
Gizzy
A gentleman, a scholar, and a railway modeller....
As Phil mentions, I'm not sure this is the case for DCC.
The direction of the loco is done by the decoder, and changing the DCC 'polarity', (which is a modulated frequency signal carried by an alternating voltage) via a DPDT switch wouldn't work....
gscalerookie
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This was the best I could do to get it to connect. Any suggestions? Putting the straight on the diverging side didnt allow me to connect
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Gizzy
A gentleman, a scholar, and a railway modeller....
Less curves, just add an extra curve to turn past 180 deg, and more straights.
I think it's 9 R3 curves....
gscalerookie
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Ok tried the 9 still couldn’t connect
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Gizzy
A gentleman, a scholar, and a railway modeller....
You just need a short straight at the half way point of the curve, possibly LGB 10152 for Anyrail.
But in practise, the flex in the track will let you connect....
Rhinochugger
Retired Oik
It all depends what you are wanting to run - a reverse curve in LGB R3 isn't too bad, but what you could do, if you have space, is insert a short straight between the reverse curves, and an equal one the opposite side - that'll keep the geometry in order.
gscalerookie
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Something like this?
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gscalerookie
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I have long trains like the ns rescue trian. I wanna say it’s 23” at least without cars. I just remember reading somewhere that you didn’t want the reverse turn and if you had to, at least put straights in. So my goal was to have a reverse loop with minimal reverse curves
Gizzy
A gentleman, a scholar, and a railway modeller....
I think you've hit the spike in the sleeper....
Rhinochugger
Retired Oik
Yep, I'd only seen your Mk1 diagram, and hadn't got as far as Mk2 - a better solution and a bit closer to prototypical track layout.
Gizzy
A gentleman, a scholar, and a railway modeller....
A few miles away to the north of Cambridge, is the city of Ely. To the north of the station and city limits, is Ely North Junction.
If you look at this on Google Maps or similar, you will see a prototypical 'balloon loop' which is very similar to your Anyrail plot.
It allows freight trains from NW England to route North to Kings Lynn and North East to Norwich without having to reverse and run round in Ely station....
If you look at this on Google Maps or similar, you will see a prototypical 'balloon loop' which is very similar to your Anyrail plot.
It allows freight trains from NW England to route North to Kings Lynn and North East to Norwich without having to reverse and run round in Ely station....
Rhinochugger
Retired Oik
.............................. and includes a tight radius bend with check rails if I remember rightly
I've been across the bridges and crossing at Queen Adelaide many, many times, and I've never worked out which line is which, I really ought to look at a map!
craigwrdouglas2
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I've had the Massoth Module down in my layout It's been down for 15 years without issue, and it stays outdoors all year round inside a purpose built jigstones building that is sealed to prevent water getting in.
I have it setup with the sensor track configuration so there is no short, but if you are going to fit it this way you might need to take this into account in your track geometry. (the sensor track components are included with the module)
Manual is here:
Product page is here:
www.massoth.de
I have it setup with the sensor track configuration so there is no short, but if you are going to fit it this way you might need to take this into account in your track geometry. (the sensor track components are included with the module)
Manual is here:
Product page is here:
8157001 Reverse Loop Module – Massoth Elektronik GmbH
www.massoth.de
The Massoth one appears to be more robust for outside use than the LGB ones, though inside a building does help. We originally had LGB ones on the Ruschbahn in plastic food containers, but they broke down letting in damp that trashed them, done now I would have sprayed to containers Matt Black to stop the plastic breaking down. Even better if possible would be to have the units inside even a dry shed would be good with extended wires well labeled or marked to the track sections.