Automatic twin reversing loop not working

T

Tony ab

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15 Dec 2019
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Glasgow
Hi

I am very new to LGB train layouts and I am trying to get a twin fully automatic reversing loop to work.

I found the attached layout on the web and have set up my layout I believe identically however the train goes round the loop on the left perfectly but keeps stopping on the one one the right. I have marked on the attached file the layout and where the train stops (Red arrow).

After many hours of wiring, rechecking and rechecking I just can not get it to work.
Does anybody have any ideas what the problem could be

Thanks

Tony
 

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dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
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St.Neots Cambridgeshire UK
Hi

I am very new to LGB train layouts and I am trying to get a twin fully automatic reversing loop to work.

I found the attached layout on the web and have set up my layout I believe identically however the train goes round the loop on the left perfectly but keeps stopping on the one one the right. I have marked on the attached file the layout and where the train stops (Red arrow).

After many hours of wiring, rechecking and rechecking I just can not get it to work.
Does anybody have any ideas what the problem could be

Thanks

Tony
Have a look at my short tutorial on YT, plenty more there as well.


opps sorry you are not DCC, hm think that each loop should have separate reverse function also there appears to be no feed to the central section?
 
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T

Tony ab

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Hi John

Thanks for the feedback, I should have stated that the direction of travel as it goes into the Loop B is clockwise so it goes all the way around to T3 at which point it flicks the points motor PM2 and then it stops.

Hope that may make it clearer

Thanks again

Tony
 
dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
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Ok so looking at your diagram what I think should happen is this. When T3 is hit point should indeed be set to allow train to depart loop but should also reverse current on MAIN TRACK not the loop as if you do it on the loop train would immediately go backwards.

if you are happy with the train going round the loop same way each time a better way is to feed the loops via diodes as the LGB Reverse Loop for Analogue tracks does, then all you need to do is reverse the point and main track as the train will be coming out if the loop the other way and things will work just fine. If you are driving the loco you just reverce the controller each time before the train exits the loop.

Hope diagram of the diodes and isolations below makes things clear. You would need this in each loop.

EDIT I realised that the original drawing was wrong, you need Diodes at each end of the reverse loop, I have added the missing ones in Red. Sorry if I caused confusion with this.
326682C3-7692-4B97-834E-E9CF4B08E16E.jpeg
 
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T

Tony ab

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Hi John

Certainly looks easier to wire, thanks will try if your advice does not sort the problem.

If I try to go round anti clock wise, ie the points are set for that, then the whole system does not work - the straight or the Loop A

Tony
 
dutchelm

dutchelm

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24 Oct 2009
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The whole lot seems over complicated.
Get rid of the point motors on the loops & convert the points to sprung points so the train always goes the same way around. This means removing the motors & replacing them with hand actuators.
Wire permanent feeds to the loops. It the train always goes the same way you do not need a reversing relay on these feeds.
Feed the centre track through a reversing relay operated by a reed switch on each loop.

One relay, a signal works well as you can see the direction of the power. 2 reed switches,

Simples!
 
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Tony ab

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15 Dec 2019
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Glasgow
Hi john
Switched the connections at the back of pm4. Train now stops at T4 position.

Will try your proposed layout later in the week as will perseve with this layout as it definitely worked last year, the train layout is a Christmas one hence it gets set up and dismantled every December/January

Any other reconfigureing would be helpful

Tony
 
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Tony ab

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15 Dec 2019
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Hi dutchelm

You are spot on , so complicated, but bought all the gear last year and it worked but I am loathed to start again any buy more gear for something that worked before.

Tony
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
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When you say it 'stops'..

Is this just a 'no-power' stop, or does it trip the system? - Make the controller cutoff.
 
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Tony ab

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Glasgow
All

My friend came round with a current meter. The problem was my 1015t twin isolation track piece was not working and current was passing through it.
On further inspection, taking the cover off there was wires connecting across the gap.
Ahhhhhh
I bought this last year new as a spare so hence it worked last year but I inadvertently put it into the layout this year and was not aware there was a cable that stopped it working as an isolation unit.

Thank you all for your support and ideas.

Tony
 
dunnyrail

dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
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Just to complete this, I had made an error in the diagram with my post #5, corrected now.