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Turnout Frog Sparking

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  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Sunday, August 17, 2014 9:39 AM

My club (Old Newburgh Model RR Club) had many old Atlas switches with the plastic frogs that were prone to shorting after we switched to DCC. They definately predate the production problems that Atlas is having. Several switches had the metal insulated frogs that didn't have the problem. We changed most of them to Peco long radius but some of the Pecos still have the same problem due to wheels with wider treads.

  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Sunday, August 17, 2014 6:03 AM

retsignalmtr

A dab of non metalic nail polish to extend the insulated area of the frog will stop the shorting and sparking. This will have to be reaqpplied when it wears off by use or an abrasive track cleaner. This is nothing new. I have this problem in both HO and N gauges on my home layout and on my clubs layout with Peco switches. The application of the nail polish stops the occurance. 

 

If this turns out to be the problem, it happens not only with Peco but also Walthers Shinohara, especially the 3-way switches.  

But, this is an Atlas Custom Line #6 turnout, so I will be interested to find out what the OP discovers about the short. I have upwards of 60 of these specific turnouts on my layout and never had that problem.  I am not saying that it is not the problem, however, if this turnout is part of a new batch of the post-production problem in China.  The new batch may have tighter tolerances, intended or not.

Rich

Alton Junction

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  • From: Westchester NY
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Posted by retsignalmtr on Sunday, August 17, 2014 5:39 AM

A dab of non metalic nail polish to extend the insulated area of the frog will stop the shorting and sparking. This will have to be reaqpplied when it wears off by use or an abrasive track cleaner. This is nothing new. I have this problem in both HO and N gauges on my home layout and on my clubs layout with Peco switches. The application of the nail polish stops the occurance. Running with DCC, this sparking will cause a short that will stop every train that is running due to the trip speed of the command stations short detection. DC short detection is not as fast so your train just keeps rolling past the bad spot. It usually happens with the loco taking the diverging route through the switch.

Another fix could be to shim the guard rail with Styrene to keep the wheel from reaching the other rail. Cars with metal wheels will do the same thing occasionally.

  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Sunday, August 17, 2014 5:02 AM

Here is the turnout diagram that I use to identify the various rail segments.

To test for continuity on the various rail segments, dial your multimeter to ohms.  Touch the two metal probes from your multimeter to the two ends of a rail segment.  

For example, if you place each probe near the opposite ends of the throught stock rail, you should get a reading, indicating continuity.  Same for the divergent stock rail.

What I would be most interested in, though, is a continuity test between the divergent point and the divergent frog rail.  Although these are two separate rail segments, they are connected together by built in rail jumpers, so touching one probe to one rail segment and one probe to the other rail segment, you should get a reading, indicating continuity.  You could do the same continuity test for between the through point and the through frog rail. 

Incidentally, the Atlas Custom Line has an isolated metal frog.  So, another informative continuity test is on the frog itself.  If you place one probe on the frog and the other probe of any one of the four adjoining rail segments (through frog rail, divergent frog rail, through closure rail, divergent closure rail), you should not get any reading.  If you do get a reading, the frog is not properly isolated, and that could cause a short.  Check all four adjoining rails with a series of four continuity tests.

Rich

Alton Junction

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Posted by zstripe on Saturday, August 16, 2014 9:55 PM

I would take it back, it is defective. There are flat metal jumpers under the frog that are separated by the plastic that is injected into the mold....obviously that one does not have the correct amount of insulation. No way to fix it without taking the frog out.

I have had it happen before. I called Atlas and they made arrangements to send me two, no charge, they wanted the defective one though and paid shipping.

Take Care! Big Smile

Frank

  • Member since
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  • From: Ontario Canada
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Posted by Mark R. on Saturday, August 16, 2014 9:37 PM

If you want to continue diagnosing the problem, use your meter to see if there is any kind of power at all in the frog itself. Judging by your description, the frog is solid metal, and out of the package should have no connections to it for power. If there is, the rail running under the bottom of it may inadvertantly be touching the bottom.

Mark. 

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
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  • From: Sierra Vista, Arizona
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Posted by cacole on Saturday, August 16, 2014 8:53 PM

I'd take it back to the place of puchase and ask for a replacement or refund on a defective item.

Atlas has had to change manufacturers in China and may be having QC problems.

 

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Posted by NittanyLion on Saturday, August 16, 2014 8:13 PM

Yes, its a brand new #6 Custom Line.  Got it about a month ago.  The hobby shop I got it at date stamps their inventory and they'd received it in early July.  There is something different about it compared to other Atlast turnouts, at least as best I remember.  On the bottom of the frog, there's a section of exposed rail instead of a fully plastic frog-bottom.  I don't know if this is significant.

I cleaned the area, to remove any possible metal debris.  Nothing was located and the problem persisted.  I put down masking tape, just in case there was something making contact that evaded me, laid the track on top, still did it.

Checked the wheelsets, everything was in gauge.  I checked the track, but I'm not sure if I interpretted the NMRA gauge correctly on the flange side.  Wheelsets are, like, the easiest to do with that tool.

Took the offending turnout away from the layout and laid it down on a scrap for Homasote (with some sectional track to use as approaches) that I know has no metal fragments or wire or anything anywhere nearby.  Again, the bright orange sparks!  Putting my face much closer than I could before (and with eye protection!), I have observed that the first discharge occurs right as the leading wheel enters the from the diverging leg it does not do so when its entering from the main.  Additional observation shows that there's three locations that cause sparking: entering the frog, right at the V part that I don't know the name of, and when it reaches that rail just beyond the frog when its back to "regular rail."  I should consult a diagram to get those names.  Each wheel causes it at each one of those locations.  Some sort of...something is going on during this testing because its starting to remove the blackening from the frog and expose what appears to be nickel silver rail.  I have suspended testing, as it seems to be causing damage.

richhotrain
 

Take the turnout off the layout and test each rail segment for continuity.  I am wondering if a jumper is misplaced.

 

How would I go about doing this, procedurally?  I have a multimeter.

I don't want to give up on this guy yet, but if I do...is this something I should take up with Atlas, given that it appears that this is defective?

  • Member since
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  • From: Ontario Canada
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Posted by Mark R. on Saturday, August 16, 2014 5:36 PM

Are they Snap switches with the plastic frog ? If so, the problem is that the two diverging rails embedded into the plastic frog are too close together. The wheel tread is wide enough to contact both these rails at the same time causing a short ....

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

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Posted by richhotrain on Saturday, August 16, 2014 4:45 PM

If I understand you correctly, the turnout is brand new, right out of the packaging and onto your layout.

Take the turnout off the layout and test each rail segment for continuity.  I am wondering if a jumper is misplaced.

Sounds like the frog is shorting, badly.

Rich

Alton Junction

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Posted by jrbernier on Saturday, August 16, 2014 3:57 PM

  Sounds like the frog is shorted to the main.  Maybe there is wire or something metal under the turnout.

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Turnout Frog Sparking
Posted by NittanyLion on Saturday, August 16, 2014 3:40 PM

So I'm splicing in a turnout after coming across a store with a supply of Atlas turnouts.  While testing to make sure everything was fitting, before painting and such, I ran a locomotive (Athearn BB of indeterminate age (10 years?)) over it and the frog threw sparks when the locomotive ran over it.  Not the little blue ones that you liked when you were a kid.  Big scary orange ones.  It only does it on the divergent route and both directions.  I'm running straight DC too.  They're quite big and I swear it pitted the frog and the wheels on that side of the truck.  I ran it back and forth a bunch trying to see if I could figure out what's going on.  

I tried a second BB (a much older one that I've had for 20 years now) and it did it too.  There's no hesitation or anything.  They just plow right through, looking like they've crushed a guy with a cutting torch.  I also attempted it with a DC BLI F unit that I have and that produced a different result.  No discharges, but the loco would stop dead at the frog.  Either truck too.  Like first truck would stop, I'd nudge it, it would move, second truck stops it dead.  I tried cleaning the frog with some 91% iso, figuring maybe some sort of material from the manufacturing process was on there, but it made no difference.

I've never seen this before and I'm quite vexed.

Oh, also tried a metal wheelset'ed truck and it didn't do anything.  Straight leg also doesn't do anything with the locomotives (all three test units).

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