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Shorts at Frogs

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Shorts at Frogs
Posted by RicZ on Tuesday, June 23, 2015 1:44 PM

I have been experiencing some shorting at several of my turnouts.  Most of the problems seem to be on Atlas #6 turnouts, both code 83 and code 100 (in hidden areas).  I have read that shorts can occur when the wheels bridges the "clear" and "divergent" frog rails.

Several suggestions have been offered to correct this condition, and I would appreciate any others that may be out there.  One solution has been to paint these rails after the frog with nail polish, but since that wears off and has to be replaced, it is not a suitable solution to the problem, especially in the hidden areas.  

Another solution has been to place a 0.005" shim on the opposing guard rail to force the wheels away from the frog.  Is this a good solution or just an "iffy" one?

The last solution that has been offered in the past is to increase the insulated area by cutting gaps further aft of the frog.  How far back should those gaps be cut?  2mm, 5mm or an inch?

I am open to any and all suggestions and I greatly appreciate any help.

RicZ

Tags: shorts frog
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Posted by ICOrange on Tuesday, June 23, 2015 2:16 PM

An easier first step would be to check the gauge of the wheels.  Using an NMRA gauge for your scale would help determine if the problem is the turnout or the wheelsets.

Good Luck!

Dan.

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Posted by wp8thsub on Tuesday, June 23, 2015 3:01 PM

The diverging rails from the frog only have to be far enough apart to keep a wheelset from bridging across them.  Check your turnouts and any equipment that shorts to be sure the rail spacing is close enough for the wheels to short across them.

My layout probably has around 50 Atlas #6 turnouts, both code 100 in staging and 83 elsewhere.  I've never experienced shorting at the frogs, and the diverging rails are far enough apart after the electrical gap I can't imagine having any wheels wide enough to short.  Maybe your turnouts have some different dimensions, or you're running different equipment with problematic wheels.  Before doing anything drastic, ensure the wheels on the problem equipment are sufficiently wide to cause the issue.  You may have something else going on, like a steam loco shorting out going through the diverging route of a turnout due to pilot or trailing wheels or metal trucks hitting the frame.

Rob Spangler

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Posted by richhotrain on Tuesday, June 23, 2015 3:20 PM

Like Rob, I have a huge number of Atlas Custom Line #6 turnouts, both Code 83 and Code 100, and I have never experienced a short on the diverging frog rails.

But I have had that type of short on Peco Code 83 Insulfrog turnouts and crossings.  I have used clear nail polish, but a more permanent solution is a narrow strip of masking tape laid over the point where the frog rails diverge.

Rich

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Posted by wp8thsub on Tuesday, June 23, 2015 4:45 PM

richhotrain
But I have had that type of short on Peco Code 83 Insulfrog turnouts...

That does bring to mind a question, is the OP remembering the brand correctly?  I wonder mostly because a buddy recently reported some trouble with an "Atlas" turnout, and couldn't get any of the typical Atlas troubleshooting to solve the issue.  The turnout in question was actually an older Shinohara, and he had just forgotten.  The explanation he gave for the trouble made no sense for an Atlas product, but things were easily resolved once the brand was identified.

Rob Spangler

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Posted by yankee flyer on Wednesday, June 24, 2015 7:21 AM

RicZ

Hi.

Some times the gap between the rails is not wide enough and I have used a narrow file to increase this gap. Worked for me.

Good luck.

Lee

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Posted by RicZ on Wednesday, June 24, 2015 9:05 AM

Some additional info.  All questioned turnouts are Atlas #6.  locos are all diesels; Atlas, BLI and Proto.  Proble only occurs as the trucks pass over the frog.

RicZ

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Posted by wp8thsub on Wednesday, June 24, 2015 10:02 AM

OK so let's try some further diagnosis.  Have you measured the wheel treads, and the gaps between the diverging rails, to see if the wheels are wide enough to bridge the gaps?  Do you see physical evidence of shorting on the rail heads (pitting/"arc weld" marks) or the wheels?  If so, using a file or motor tool to remove the affected areas between the diverging rails should eliminate the problem.

Another possibility is an open instead of a short.  Atlas turnouts come with dead frogs.  If the contact between the points and stock rails and/or closure rails is poor, a loco can stall when one truck is on the frog, and the other on the points.  One whole side can lose electrical contact.  You can test for this using clip leads to temporarliy jumper around the failed connection, and solve it by soldering jumper wires.

Rob Spangler

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Posted by RicZ on Wednesday, June 24, 2015 11:05 AM

Checked the wheel gauge and width on the last engine that the problem  occurred on, a Proto 2k, Burlington E-7.  Gauge is proper and width is right at limits.  Wheels, measured with an NMRA gauge.  Should wheel width fit into the gauge or just at it (my case)?

Seperation bewteen divergent rails at the frog exit was also right at proper gauge width.

RicZ

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Posted by wp8thsub on Thursday, June 25, 2015 10:48 AM

RicZ
Gauge is proper and width is right at limits.  Wheels, measured with an NMRA gauge.  Should wheel width fit into the gauge or just at it (my case)?

 

I can't recall for certain what the standards gauge instructions say on tread width, but I seem to recall a code 110 wheel (the normal width for HO) is not supposed to drop into the notch.  It sounds to me like the wheels you measured are OK or very close.

So... measure the distance between the diverging frog rails on your turnouts to see if any of them are close enough for the correct width wheelsets to bridge across.  Again, if you find any that are too close together, look for evidence of arcing.  I'd recommend using a motor tool or file to remove enough of the back side of the rail head to keep wheels from being able to short across the gap.  Make sure the issue is being properly diagnosed and it's a short instead of an open, otherwise fixing for a short won't do anything.

Rob Spangler

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Posted by RicZ on Thursday, June 25, 2015 11:38 AM
Pretty sure it is the divergent rail gap since it is very short. DCC sound Locos restart immediately after a short jerky pause.

I will check the gap on each switch and file/grind the gap a little wider. Thanks for your help, I greatly appreciate it.
RicZ
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Posted by richhotrain on Thursday, June 25, 2015 2:50 PM

RicZ
Pretty sure it is the divergent rail gap since it is very short. DCC sound Locos restart immediately after a short jerky pause.

I will check the gap on each switch and file/grind the gap a little wider. Thanks for your help, I greatly appreciate it.
RicZ
 

Before you file the gap and run the risk of damage, try the nail polish suggestion and see if that solves the problem.

Rich

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Posted by zstripe on Thursday, June 25, 2015 4:32 PM

richhotrain
RicZ Pretty sure it is the divergent rail gap since it is very short. DCC sound Locos restart immediately after a short jerky pause.

Just my My 2 Cents.....I believe He is experiencing loss of power at the unpowered frog of the Atlas turnout and He is calling it a short, rather than an open....Loss of power. I have never experienced any type of shorts on Atlas custom line turnouts, in all the umteen yrs. I've been using them...especially wheel threads bridging rails.

Take Care!Big Smile

Frank 

BTW: Rob Spangler, has the same thought!

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Posted by wp8thsub on Thursday, June 25, 2015 4:49 PM

zstripe
...I believe He is experiencing loss of power at the unpowered frog of the Atlas turnout and He is calling it a short, rather than an open....Loss of power. I have never experienced any type of shorts on Atlas custom line turnouts, in all the umteen yrs. I've been using them...especially wheel threads bridging rails.

I strongly suspect this as well.  Unless something really unusual is at work, I just don't see wheels on any of the locos the OP listed being able to short on Atlas turnouts.  I've never seen it happen.  I went to my train room for grins and measured the gaps on Atlas code 100 and 83 turnouts, and none of them were anywhere near close enough for any of the wheels I have to short across them after departing the frog.

I HAVE seen plenty of cases of contact being lost through the points, which, combined with the dead frog, results in hesitation as the affected side of the loco has one truck on the frog and the other on the dead point rail.  This problem can be exacerbated by the tendency of Atlas frog castings to be too high, which leads to further loss of contact as the truck goes over the frog and lifts wheels off the adjacent rails (unless you file the casting flush).  This issue especially affects three axle trucks.  Proper diagnosis is key.  I hope the OP takes the advice previously given above to rule out an open before modifying to correct a short that isn't there. 

Rob Spangler

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Posted by NHTX on Thursday, June 25, 2015 5:17 PM

  May I suggest retiring the overly wide code 110 wheel to the same place brass rail, fiber tie strip and the x2f coupler went?  I went to code 88 nickel-silver wheels and a whole list of problems disappeared along with shimming gaurdrails and painting frogs.  Time for some updated NMRA standards?

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Posted by richhotrain on Thursday, June 25, 2015 8:47 PM

zstripe

 

 
richhotrain
RicZ Pretty sure it is the divergent rail gap since it is very short. DCC sound Locos restart immediately after a short jerky pause.

 

Just my My 2 Cents.....I believe He is experiencing loss of power at the unpowered frog of the Atlas turnout and He is calling it a short, rather than an open....Loss of power. I have never experienced any type of shorts on Atlas custom line turnouts, in all the umteen yrs. I've been using them...especially wheel threads bridging rails.

Take Care!Big Smile

Frank 

BTW: Rob Spangler, has the same thought!

 

Frank, I agree with you and Rob.  I have over 60 Atlas Custom Line #6 turnouts on my layout and never had a short.  As you point out, it has a dead metal frog and that could be his problem.

Rich

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Posted by mobilman44 on Friday, June 26, 2015 5:57 AM

Question for the OP......... when were these turnouts bought/made?

In building my current layout, the turnouts that were Atlas #4 and #6 which I had purchased over many decades.  In fact, I found I had 4 generations of them.  Well, they all worked fine on the DC layout (from whence they came), but some shorted at the frogs when I was putting in the DCC layout.

Turns out wheels were touching both rails where they come to a point at the frog.  The sensitive DCC shut down the locos, while the "not so sensitive" DC did not.  I found that this only applied to the oldest generation of the turnouts, and of course did not end up using them.

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by richhotrain on Friday, June 26, 2015 5:59 AM

mobilman44

Question for the OP......... when were these turnouts bought/made?

In building my current layout, the turnouts that were Atlas #4 and #6 which I had purchased over many decades.  In fact, I found I had 4 generations of them.  Well, they all worked fine on the DC layout (from whence they came), but some shorted at the frogs when I was putting in the DCC layout.

Turns out wheels were touching both rails where they come to a point at the frog.  The sensitive DCC shut down the locos, while the "not so sensitive" DC did not.  I found that this only applied to the oldest generation of the turnouts, and of course did not end up using them.

 

Perhaps the oldest generation of Atlas turnouts exhibited that fault, but I started purchasing Atlas Custom Line Code 83 and Code 100 turnouts in early 2004 and none of them short at the frog where the frog rails converge.

Rich

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Posted by BroadwayLion on Friday, June 26, 2015 7:08 AM

Shorts in your frogs is better that frogs in ... ....

Oh Noes, Mr. LION! you couldn't resis that no could you.

 

ROAR

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Here there be cats.                                LIONS with CAMERAS

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Posted by zstripe on Friday, June 26, 2015 7:49 AM

Surely more info is needed from the OP......we're just pulling at straws here. How many engines do that? All or just one? Does the engine have both trucks picking up power? What kind is it? Lift one truck off the rails with power on....can You do that to both trucks? And quite a few more.

I have some Atlas #6 customline turnouts from the early 80's on my layout, about the only thing they changed over the yrs. really noticeable were to replace the rivets at the points. I have never had any problem's with wheels bridging rails and creating shorts and I still run Athearn BB's with sintered wheels...I've had to make the guard rail gap larger, but that's it. I also run DCC with sound engines all over the layout...real Shinohara 5 1/2's, Atlas #4's and #6's and they all work fine. Something else is going on with the OP's turnouts or engine.

Take Care! Big Smile

Frank

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Posted by zstripe on Friday, June 26, 2015 8:04 AM

RicZ

Some additional info.  All questioned turnouts are Atlas #6.  locos are all diesels; Atlas, BLI and Proto.  Proble only occurs as the trucks pass over the frog.

RicZ

 

I did not know that the OP posted this.....but I still have my doubts about the wheels bridging the rails......why don't mine do that? Have over 45 of them... had trouble with a BLI SW7 with sound always stalling on any turnout, but it was the engine...not the turnout.

Take Care! Big Smile

Frank

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Posted by RicZ on Friday, June 26, 2015 11:31 AM

[quote user="richhotrain"]

 

 
mobilman44

Question for the OP......... when were these turnouts bought/made?

In building my current layout, the turnouts that were Atlas #4 and #6 which I had purchased over many decades.  In fact, I found I had 4 generations of them.  Well, they all worked fine on the DC layout (from whence they came), but some shorted at the frogs when I was putting in the DCC layout.

Turns out wheels were touching both rails where they come to a point at the frog.  The sensitive DCC shut down the locos, while the "not so sensitive" DC did not.  I found that this only applied to the oldest generation of the turnouts, and of course did not end up using them.

 

 

 

Perhaps the oldest generation of Atlas turnouts exhibited that fault, but I started purchasing Atlas Custom Line Code 83 and Code 100 turnouts in early 2004 and none of them short at the frog where the frog rails converge.

 

Rich

 
richhotrain

 

 
mobilman44

Question for the OP......... when were these turnouts bought/made?

In building my current layout, the turnouts that were Atlas #4 and #6 which I had purchased over many decades.  In fact, I found I had 4 generations of them.  Well, they all worked fine on the DC layout (from whence they came), but some shorted at the frogs when I was putting in the DCC layout.

Turns out wheels were touching both rails where they come to a point at the frog.  The sensitive DCC shut down the locos, while the "not so sensitive" DC did not.  I found that this only applied to the oldest generation of the turnouts, and of course did not end up using them.

 

 

 

Perhaps the oldest generation of Atlas turnouts exhibited that fault, but I started purchasing Atlas Custom Line Code 83 and Code 100 turnouts in early 2004 and none of them short at the frog where the frog rails converge.

 

Rich

 
I do have an older code 100 #6 (not installed) and there is definitely a difference.  Not just plastic frogs but also very large (0.040") gaps between the guard rails.  But my current set up uses all newer track purchased since 2011.
 
I am continuing to work on this track and will either lengthen the divergent rail gaps or file the outer edges of these rails after the frogs.
 
The problem is instantaneous shorts, as verified at the CBs.  Dead frogs shouldn't bother 6-wheeled trucks.  Even when the engine passes through the frog, you can hear that static and the sound re-start.
 
Thanks to everyone for their assistance.
 
RicZ
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Posted by wp8thsub on Friday, June 26, 2015 12:29 PM

RicZ
Dead frogs shouldn't bother 6-wheeled trucks.

Atlas frog castings that sit too high can cause the entire side of the truck to lift off the live rails enough to interrupt electrical flow.  It's potentially worse with three axles since the center wheel can be pushed up and lift the others with it.  If the point rail is also dead due to faulty contact, the loco will stop.  A two axle truck is more likely to just rotate so at least one set of wheels will remain in contact with the rails.

Rob Spangler

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Posted by mobilman44 on Friday, June 26, 2015 1:32 PM

Hi,

To clarify, the oldest #4 & 6s I had were bought in the mid 1970s.  These had the opposing rails coming extremely close to one another at the point of the frog.  The slightest, momentary touch of both rails by a loco wheel shut down the DCC. 

In comparing these older turnouts with more recent ones, the problem was fairly obvious.  I confess it took me awhile to figure it out, however.

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by Redvdub1 on Friday, June 26, 2015 4:25 PM

It is important to know the specific Atlas turnout.Customline 4, Customline 3, snap switches, or the older switches with the folded metal points?  The newer CL4 switches are really good, The customline 3s will after a while need jumper wires between the point and closure rails to avoid "dead" closure rails, and we have found the really old Atlas switches will have shorts on the convergent side of the frogs.  As others have said..Atlas switches do sometimes have "humpy" frog which lift the rails up and cause loss of contact.  Shorting on the divergent side of the frog doesn't exist on our Atlas switches which range from really old to Customline 4s.  If they really are shorting you can file away outer edge of the diverging rails and fill with expoxy...and you can even put an automobile light bulb in one of the power feeds which should/might  allow you to "ride over" the short. 

George T. 

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Posted by BroadwayLion on Saturday, June 27, 2015 9:33 AM

mobilman44
These had the opposing rails coming extremely close to one another at the point of the frog. The slightest, momentary touch of both rails by a loco wheel shut down the DCC.

 

If that is the problem, the solution is simple, Cut the rails leaving the frog further from the frog with your motor tool. 1/4 to 1/2  inch should do it, ad if your locomotive trucks can bridge the gap, all well and good. If not, wire the two metal stubs together and bower them from the tortoise or other contrivance.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by zstripe on Saturday, June 27, 2015 10:27 AM

Cutting new gaps further from the one's that are there won't work...you would have to cut through the gaps that are there first, because Atlas turnouts are Jumpered under the unpowered metal frog, on the straight and diverging route, they don't rely on the points for power past the frog.

Take Care! Big Smile

Frank

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Posted by richhotrain on Saturday, June 27, 2015 6:08 PM

The OP says that he has older Atlas turnouts with plastic frogs, so if that is the case, then the frogs are dead and not the cause of the shorts.  He also says that the gaps between the frog rails are very wide which, if true, would rule out wheel flanges cause the shorts when touching rails of opposite polarity because that only occurs where the gaps are too narrow.  So, who knows what the problem is unless and until we get further info from the OP.

Rich

Alton Junction

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Posted by SouthPenn on Saturday, June 27, 2015 11:24 PM

Maybe something from Proto87 would help.

http://www.proto87.com/

Or maybe Fast Tracks

http://www.handlaidtrack.com/

 

South Penn

South Penn
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Posted by cacole on Sunday, June 28, 2015 6:52 PM

Atlas frogs at one time were higher than the adjoining rail, which would cause locomotive wheels to be lifted off the rail and the loco would stop.  The solution was to sand or file down the height of the Atlas plastic frog.

The OP may have some of these turnouts on his layout.

 

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