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Is it absolutely necessary to fill the gaps when isolating frogs?

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  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, January 22, 2016 6:49 AM

 One other point - the gap doesn't have to be within the turnout dimensions. You can gap those diverging rails anywhere, as long as they are gapped. The whole section from frog to gap will be powered by whatever you use to power the frog, so you don;t want to put the gaps 10 feet down the track, but if you leave 6 inches of rail past the frog so it has support and then cut gaps, it will be fine. I'm looking at some Peco Code 83 Electrofrogs I have on my desk and there are only 4 ties with support past the frog - the 5th one has the tie hollowed out underneath so the rail joiner slides on without popping the rail off the spikes. I'm not so sure I'd want to cut in there, too close to the frog and the frog has little support, too close to the end and there's nothing to hold the little cut bit of rail in place. I was planning to put together a small switching layout and just use the Peco insulated joiners - they are very tiny and clear, nearly invisible when in place (at least the Code 83 ones are). On the 'real' layout I think I'll just gap a few inches down the adjoining flex track and solder the short piece of rail to the turnout. That also means the frog feed doesn't have to use the existing attachment point under the turnout - anywhere prior to the gap will feed the frog area. If there's no room to leave space before cutting, I'll probably just use the Peco insulated joiners.

                                    --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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  • From: Dearborn Station
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Posted by richhotrain on Friday, January 22, 2016 5:23 AM

hon30critter

Everyone:

Thanks for your answers.

So far I have used a dremel saw with a reinforced cut-off wheel. It cuts quite well but the gap is larger than I would like it to be. I will give the thinner discs a try but my hands are not all that steady so breakage will likely be a problem. Eye protection for sure! Someone recently suggested putting two discs in the mandrill at the same time to reduce breakage. That makes sense but the cut will then be almost as wide as with the reinforced disc. I'll give it a try and report back.

One thing I did notice on one of the Peco Electrofrog code 100 medium turnouts was that after I cut the gap the rails went out of alignment. That turned into a bit of a challenge to fix.

Regards

Dave

 

Dave, in that case, why not just fill in the gaps?  Eliminate the risk of breakage and eiminate the need for two discs instead of one.

Rich

Alton Junction

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  • From: Bradford, Ontario
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Posted by hon30critter on Thursday, January 21, 2016 9:03 PM

Everyone:

Thanks for your answers.

So far I have used a dremel saw with a reinforced cut-off wheel. It cuts quite well but the gap is larger than I would like it to be. I will give the thinner discs a try but my hands are not all that steady so breakage will likely be a problem. Eye protection for sure! Someone recently suggested putting two discs in the mandrill at the same time to reduce breakage. That makes sense but the cut will then be almost as wide as with the reinforced disc. I'll give it a try and report back.

One thing I did notice on one of the Peco Electrofrog code 100 medium turnouts was that after I cut the gap the rails went out of alignment. That turned into a bit of a challenge to fix.

Regards

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    November 2002
  • From: US
  • 2,455 posts
Posted by wp8thsub on Thursday, January 21, 2016 7:55 PM

I rarely fill these gaps.  They're often useful to handle expansion and contraction as well as electrical isolation.  If you have one that closes, try coating the ends of the rails with something like CA for insulation.

Rob Spangler

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Posted by maxman on Thursday, January 21, 2016 7:32 PM

riogrande5761
One suggestion I've read is to not install insulated rail joiners on the diverging rails, but instead use standard rail joiners and cut the rail just past the metal frog,

If it is otherwise not necessary to cut the diverging rail, I would just use an insulated joiner to keep the diverging and connecting rail in alignment.  I'm not sure I see a virtue to closing an existing gap and then cutting another.

  • Member since
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Posted by riogrande5761 on Thursday, January 21, 2016 2:05 PM

Speaking of gaps, I have some older pre-DCC friendly Walthers (Shinohara) code 83 #8 curved turnouts.  I was testing continuity after wiring drops in my yard and found that (as some have commented), the bronze wiper under the points do not reliably transmit routed power to the rail in the divergent part of the turnout.  Ok thats beside the point - apparently using a relay to send power to the correct rail is the long standing solution to that issue.  Moving along to the cut rail part...

One suggestion I've read is to not install insulated rail joiners on the diverging rails, but instead use standard rail joiners and cut the rail just past the metal frog, which othewise causes a short when a train enters the turnout when it is thrown the wrong way.  So when cutting the rail, some have suggested using a Dremel Cut off wheel but I've some experience with those and don't see that going too well - melting ties with the heat, getting an angled wierd looking cut, a wide cut and maybe a nasty accident if not careful.  About the only other way I can think of is the old razor saw method. 

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by selector on Thursday, January 21, 2016 1:42 PM

It depends on the gaps....how wide, if they have rough edges, and even where they are.

Fast Tracks turnouts with the multiple copper clad ties must have the frog fully isolated for reasons that those who understand their construction will realize.  Tim Warris shows him using a jeweler's saw with a super-fine filamental hairlike blade. It cuts a very fine, barely perceptible gap in four places once they are all completed.  I have several longish #8's cut like that because I went ahead and paid through the nose for such a saw from the States.  I have never had the two adjacent rail ends close for any reason, and never had a short. I have used several of them on two layouts now, and will use them a third time very soon.

Assuming you don't mangle the rail ends, or twist or torsion the rails when you make the cuts, there is almost no chance you'll see a marked rise in derailments due to the gaps.  If you do, or if you are worred about it, simply take a small flat needle file and gently file the tire bearing surfaces edges and do the same for the inside flange faces at those gaps.  I think it's likely to not be needed, but it couldn't hurt to swipe the gaps with something to make them that much smoother.

In places where I have elected to use a fine cut-off disk in a hobby power tool, the gaps are larger, and unfortunately I have snagged and lifted the ends when I attempt to withdraw the spinning disk from the fully cut gap.  I'm getting older and my grip isn't as steady as it used to be.  Cutting a commercial turnout like a Peco Insulfrog to creat gaps near the frog is un-necessary, but if you wanted to isolate an Electrofrog version just 'cuz, I would clamp it and sever the frog in the same four places using the same jeweler's coping-style saw.

JXC
  • Member since
    January 2016
  • From: Vancouver, BC
  • 35 posts
Posted by JXC on Thursday, January 21, 2016 12:08 PM

I find installing the insulation in gaps a bit of a challenge.  The difficulty is that I haven't yet found a glue that will attach a piece of styrene to the rail ends sufficiently well to stand up to the stresses of cutting and filing the styrene to match the  rail profile.  I've had greatest success when the styrene is glued to the roadbed and protrudes up through the rail gap, but that obviously depends on the roadbed material (I have ABS plastic roadbed for a weather-proof outdoor setup). Has anybody tried these http://www.handlaidtrack.com/StopGap-Rail-Gap-Fillers-p/sg.htm (which look like they are made of wood instead of styrene)?

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Posted by richhotrain on Thursday, January 21, 2016 5:02 AM

The gaps should be filled for several reasons: to avoid unintended closure, to avoid derailments, just to mention two.

Rich

Alton Junction

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Posted by mlehman on Thursday, January 21, 2016 3:27 AM

Dave,

ME doesn't fill the gaps in their HOn3 turnouts. They seem to work just fine.

Mike Lehman

Urbana, IL

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  • From: Bradford, Ontario
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Is it absolutely necessary to fill the gaps when isolating frogs?
Posted by hon30critter on Thursday, January 21, 2016 2:08 AM

Call me lazy if you want, but I'm asking why it is necessary to fill rail gaps in turnouts?

As many of you are aware, I'm in the process of powering the frogs in my Peco code 100 Electrofrog turnouts. The common practise is to fill the rail gaps after they have been cut. I can see the necessity for filling gaps in flex track so the sliding track doesn't close the gap. However, the rails in the turnouts seem to be pretty well anchored in place. Why fill the gaps? If the polarity is correct there won't be any difference from the frog to the closure rails. Even if the polarity was not correct, filling the gap wouldn't change anything. Peco makes no mention of filling gaps if you are isolating the frogs.

So, what say ye?

Thanks

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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