Y turnout

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Ogster
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Y turnout

Postby Ogster » Fri Feb 24, 2017 12:06 am

Chaps

DCC layout and wiring up a Y turnout to enable loco to reverse direction when running on the main - this via two normal turnouts to the main.

I have a DPDT switch in place to reverse the (polarity?) of the short section of track from the head of the Y to facilitate the changeover in wiring required when the loco runs over the electrofrog Y points again in the other direction. Y is fully isolated to the the two spurs leading to the main.

I also intend to wire up the Y point itself using a PECO points motor with the microswitch - PL15? or a similar Tortoise.

However the Y point blade contact is not great. Loco stalls. How would I wire the frog up to ensure sound contact for any passing loco? Presumably I wire the frog to the common on the microswitch, but for the DCC supply, I assume it must be from the head of the Y - which in itself is controlled by the DPDT?

Or - is there a simpler method?

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Flashbang
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Re: Y turnout

Postby Flashbang » Fri Feb 24, 2017 11:36 am

Is the Y point Insulated frog or Electrofrog?

This shows the basic idea for a Y if this is what you're intending to do? Link Scroll down a little to the Y formation. The Reverse Loop Module can be replaced with a Y point motor operated Double Pole Double Throw (DPDT) switch if wished such as the Peco PL15. If you have the IRJs as shown on the end of the Y point you can bond the switch rail to the adjacent stock rail on each side of the point, this then overcomes any poor point blade contact onto the stock rail when closed togetehr
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Ogster
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Re: Y turnout

Postby Ogster » Fri Feb 24, 2017 4:07 pm

Flashbang

Thanks for the link - useful - and electrofrog Y.

Still unsure of your solution. Surely the DCC feed has to be reversed somehow if the loco is to travel down the other arm of the Y? I have done this with a DPDT for the DCC feeds only.

Also

If you have the IRJs as shown on the end of the Y point you can bond the switch rail to the adjacent stock rail on each side of the point, this then overcomes any poor point blade contact onto the stock rail when closed together


Not sure about the above either - sorry!. Won't this mean the switch rail/frog is fed by both DCC feeds simultaneously - which is clearly unacceptable.

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Flashbang
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Re: Y turnout

Postby Flashbang » Fri Feb 24, 2017 5:10 pm

Ogster wrote:Flashbang

Thanks for the link - useful - and electrofrog Y.

Still unsure of your solution. Surely the DCC feed has to be reversed somehow if the loco is to travel down the other arm of the Y? I have done this with a DPDT for the DCC feeds only.

Also

If you have the IRJs as shown on the end of the Y point you can bond the switch rail to the adjacent stock rail on each side of the point, this then overcomes any poor point blade contact onto the stock rail when closed together


Not sure about the above either - sorry!. Won't this mean the switch rail/frog is fed by both DCC feeds simultaneously - which is clearly unacceptable.

Hi
On DCC you only ever reverse the polarity on the rails for a reverse loop or the top straight bit of the Y. This is usually done automatically by using a DCC Reverse Loop Module or a Dual Frog Juicer or via a DPDT switch fitted to the Y points motor. All this is doing is matching the polarity across the IRJs at the end of the Y point so as no short occurs as the metal wheels travel over the IRJs. E.G. if no switching is used then red feed rail meets a black feed rail!

Bonding the stock rail to its adjacent closure rails is the normal way of bonding the two together. However you MUST have a gap / cut in each closure rail. This isolates the rails from the gap towards the frog and the Vee rails to the IRJs. These are feed via frog polarity switching as per normal for electrofrog points. The rails (Closure and switch blades) are bonded together between gap and pivot on each side, thereby making the stock rail and moving switch rail all the same polarity, this removes the reliance on the switch rail blade making 100% contact onto the stock rail when the two are closed together. Sorry I assumed you understood this conversion!

Unless Peco have altered the Y point, last time I looked at one (Electrofrog version), they hadn't fitted the factory gaps and insulation in the two closure rails which most of their other electrofrog points have factory fitted. The gap can be cut in each closure rail between the pivot and the frog with a razor saw, Jewellers Piercing saw or a Dremel with metal slitting disk, of all the three I prefer the Jewellers piercing saw as the cut is much finer but has to be done before the point is laid. The cuts being made between sleepers.
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Ogster
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Re: Y turnout

Postby Ogster » Fri Feb 24, 2017 7:46 pm

Flashbang

Right thanks again - I think I understand, but as the Y is in situ, pinned, glued and ballasted and only insulated at the the two arms it could be tricky to effect!

Plan B then

At the head of the Y is a siding - just for the loco. This also joins to the Y point proper with no IRJs but with fishplates as normal. On the siding, I have the two droppers leading to a common (middle pair of terminals) to a DPDT switch. To the two terminals on on the left is fitted a DCC feed, to the other two on the right, the same feed but reversed. Throwing the switch takes care of the reverse polarity required in order for the loco to travel down/back either of the the two arms.

For the poor contact blade issue, I was simply thinking of wiring in a 6 pin Peco PL15 points motor or a Tortoise - one with a microswitch anyways. Power for the motor and (mimic board) switch would take up the usual 3 pins, another for the frog, and the other 2 would lead back to the droppers on the siding - whose polarity in turn is controlled by the DPDT.

Question then

Would this work as a cure for the poor contact issue? Presumably, as there are no gaps in the closure rail, then whatever polarity the frog is, is also conducted to the closure rail - which should be the same as the stock rail which it comes into contact with?

This of course depends on throwing the DPDT correctly beforehand!

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Flashbang
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Re: Y turnout

Postby Flashbang » Fri Feb 24, 2017 10:33 pm

I'm somewhat lost?
You say your siding has no IRJs only two in the end if the Y points Vee rails. So the outer rails are through connected? If you flip the sidings rail polarity via a DPDT toggle switch, Surely in one position the sidings rail match the exit track polarity out onto the main line but flip the switch the other way and the two rails flip polarity too then opposite rail polarity occurs connecting a positive rail to a negative rail?

Think a drawing of the the track plan, all IRJ locations and all rail feeds etc is needed.
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Ogster
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Re: Y turnout

Postby Ogster » Fri Feb 24, 2017 10:46 pm

Think of the Y inverted. The top is connected to the dead end siding with normal fishplates

The two lower arms are fully insulated with 4 IRJs to the two spurs leading to the main

kebang
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Re: Y turnout

Postby kebang » Sat Feb 25, 2017 2:08 am

I've been following this thread, or trying to, but without a diagram of your track I don't think anyone here will be able to help.

However the below diagrams may be of use
.
Y wiring.jpg
Y wiring.jpg (90.59 KiB) Viewed 874 times

You can use FIG 2 if your loco is the only electrical connection to the track. Use FIG 1 if any of your trains have rolling stock which draws power from the track, coach lights etc. If this is the case then whole train length needs to fit into the orange section.

Ogster
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Re: Y turnout

Postby Ogster » Sat Feb 25, 2017 4:20 pm

Diagrams no use. I shall attempt a simpler explanation.

Forget the Y point is inverted. It actually is so if looking at the layout, but it is immaterial.

The stem of the Y is connected with normal fishplates/RJs to a very short dead end siding.

One arm of the Y, fitted with 2 IRJs, connects with track which veers left along the main line and is connected to it with normal fishplates/RJs to a normal turnout

The other arm is similarly fitted with 2 IRJs, connects with track which veers right along the same main line, - but further along the track than above - and is connected to it with normal fishplates/RJs to a normal turnout.

All turnouts and the Y are electrofrog.

The siding leading from the stem of the Y is connected up to the DPDT - as previously mentioned - to allow the reverse polarity required for the siding and Y point when the loco stops on the siding and runs in the other direction. This works.

Poor contact at the blade means the loco stalls on the point. Suggested solution as previous post.


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