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I was wondering if a reverse loop module would work with Hornby Digital and if you had a non isolating point would there be any issues?

Do you need a non isolating point at the entrance to the return loop?

Do points switch automatically when using a reverse loop module and how does this work to avoid a derailment?

Hornby do an isolating track section and point motors and also an accessory module.

I'm thinking of doing a narrow single line modular layout like the one done by that Z gauge Scandanavian modeller featured elsewhere using a similar composite material as the base and running it all around the perimeter of the rooms at home!

This has been covered generally elsewhere but it got a bit overcomplicated. I was thinking of using the Bachmann reverse loop module.

Happy modelling
Gary
 

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>I was wondering if a reverse loop module would work with Hornby Digital and if you had a non isolating point would there be any issues?

A reverse loop module is required regardless of the behaviour of the point. The problem with a reverse loop is that the "left" rail eventually makes contact with the "right" rail which means you have a short. The reverse module deals with this problem by detecting the short and switching the polarity in the loop so that at the point of contact the polarities of the rails are correct.

This is another area where Allan Gartner's website has clear diagrams which explain what is going on. You can get to it via this forum's Links - DCC section.

David
 

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You just need a double break at each end of the reverse loop and supply power to this section via the reverse loop module. Anyone's reverse loop module should do --- I have a Tony's trains one at the moment and have a Digitrax AR1 on order (its only £20). The easiest way to create the required break is to use 4 insulating joiners.

The only complicated bit is that the reverse loop module needs to trip at a lower current than your DCC system unit. In the case of the Tony's train unit you tell them what you have when ordering and they set it for you. The AR1 has an adjustment that you do yourself. The Bachmann unit will no doubt suit any of the lower power DCC systems.
 

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QUOTE Do points switch automatically when using a reverse loop module and how does this work to avoid a derailment? You can set up points to switch automatically with the new Ecos system and S88 occupancy detectors. Some other top end systems like Maerklin Central Station and the new Viessman Command centre will do this too. Other systems may need with extra equipment and software. What you would need to do is to set the S88 occupancy detector a given distance before the point and set your system to switch when a loco passes the S88 detector. This process would be independant of the reverse loop module. The reverse loop module only deals with current. If you set the Command centre correctly the point would switch automatically to avoid a derailment.
 

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QUOTE (Gary @ 5 Nov 2006, 13:25) <{POST_SNAPBACK}>Do points switch automatically when using a reverse loop module and how does this work to avoid a derailment?

If you only intend to "go round one way" just use a lighly sprung point (such as a Fleischmann or Roco) set to the "entry" & just run through - the extra cost of a decent point is then offset by not having to buy a point motor and/or additiona controller.

regards
Brian
 

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Discussion Starter · #7 ·
QUOTE If you only intend to "go round one way" just use a lighly sprung point (such as a Fleischmann or Roco) set to the "entry" & just run through

Thats what I was wondering. Thank you for the info.

Happy modelling
Gary
 

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Here are some good diagrams from Lenz to show how to hook-up a reversing look module.

The basic hook-up method:


This is interesting. You can keep all the yards and stations the same polarity and reverse the polarity on the mainline loop. This prevents having to install reversing sections between the mainlines within the station and goods yard areas:


Wye reversing section. Less common on British layouts though:


Turntable implementation. This also need a reversing module as the loco is swinging around and you want to drive on and off without switching direction on the controller:
 

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Discussion Starter · #9 ·
Thats good info Doug.

I've checked out some Roco points that I have and as suggested above they are absolutely perfect for the job in mind.

Happy modelling
Gary
 

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QUOTE (Doug @ 6 Nov 2006, 14:28) <{POST_SNAPBACK}>Turntable implementation. This also need a reversing module as the loco is swinging around and you want to drive on and off without switching direction on the controller:

That depends on the design of the turntable and how the turntable tracks get their power. Some have a built in commutator arrangement that reverses the power for you and a reversing module is not required. If building a turntable from scratch it's easy to arrange this.

Andrew
 

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Hi all

I am one of I am sure many who have joined the DCC revolution via Hornby's system ( My wife bought me the Pullman set for Xmas.

I used to model N gauge in the 80s and have been thinking about re entering the hobby in any case - an excellent suprise pressy.

My question is this I am planning to have 2 reverse loops on my layout - do i need two reverse modules or can i use the same one

Thanks
keith
 

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You probably could use just the one but only if there was no chance at all of a loco being in each loop at the same time. This would probably require a lot of extra wiring, so best advice would be to use 2 reverse modules.
 

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QUOTE (dbclass50 @ 18 Jan 2007, 18:25) <{POST_SNAPBACK}>You probably could use just the one but only if there was no chance at all of a loco being in each loop at the same time. This would probably require a lot of extra wiring, so best advice would be to use 2 reverse modules.
Or, if the loops are at the end of a dog-bone style layout, make the central section the reversing one using a single reverse module. You still need to be careful you don't have two trains bridging the isolation gaps at the same time.

If you can arrange auxilliary switches on your point motors (if you use them) then there's no need for a reverse unit at all. Just feed the appropriate polarity to the loop depending upon which way the points are set.

Andrew Crosland
 

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I am still confused as to what happens if the 2 reversing loops are bridged to form a triangle layout.

As im new to the forum is it possible to attach a diagram of my layout to this post? ive tried clicking the "insert image" icon but it seems to only want a URL, just like the "link" icon next to it

Can anyone help?

My main problem is I have 2 reverse loops bridged at their "tops" with points connecting to the rest of the layout; If i reverse polarity wont tha affect the rest of the track layout with other locos running DCC ?

Its rather complicated and Im starting to lose my mind!!
 

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A couple of points (no pun intended) here:-

1) To post photos / images / diagrams etc, this topic explains how.

2) The reverse loop module applies the polarity change to the track in the reversing loop, not the rest of the layout so sanity is maintained for all concerned.

I don't think we've had a topic on triangular junctions, so if you could get your image loaded, it would be great to have the accumulated wisdom of the Forum applied to it. The thought that occurs to me is that the distance through the triangle is a lot shorter than a reverse loop. If you don't restrict the triangle to one loco in steam as it were, you might need a reverse module for each leg??

David
 

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Just thinking about small triangles I think the solution for a single line triangle is as follows. I refer to the three tracks coming in as A, B and C.

Insulate both rails of sides AB and AC of the triangle just beyond the point where track A diverges to form these two sides.

If A is a stub end (or doesn't connect back to B or C except through the triangle) then just reverse the polarity of A and its point according to which way the point is set. No reverser necessary.

If A connects back to B or C by another route then insulate both rails of A one train length away from the other insulated breaks, and feed the intervening section through a reverser. This should work with trains standing on both AB and AC, but not for unsignalled type layouts where trains can queue up on track A and therefore possibly bridge the rail joints.
 
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