I'm not a user of any RTR turnouts except I occasionally use ME C55 #6's, but I have built hundreds of C55 "DCC friendly" turnouts on my bench, and from an electrical standpoint, Peco's "Unifrog" design isn't anything different than what I've been building for the last 30 years, which is a turnout with (1) an electrically isolated frog (including the frog wing rails) and (2) closure rails and point rails which are the same polarity as the adjacent stock rails.
What's the difference between Peco Streamline Code 55 N Scale Electrofrog & Unifrog turnouts??
Electrofrog Turnouts:Photo (1) - Peco Streamline Code 55 N Scale Electrofrog Large Turnout:
With Peco Electrofrog turnouts, all the rails between the straight and diverging stock rails are electrically isolated if the point rail toes aren't touching either stock rail. When the switch is aligned so that one point rail toe touches its adjacent stock rail, the entire central portion of the turnout becomes the same polarity as the stock rail the point toe is touching. This includes (a & b) both point rails (c & d) both diverging rails (e & f) both frog wing rails (g) the frog (h & i) both through rails. That's a total of 9 separate turnout and switch components whose polarity changes each time the switch's point rails are aligned.
The advantages are that the frog's polarity is very simply determined by how the switch is aligned, making it a "live" frog so even very short and small locomotives will run through it without any electrical interruption. This also eliminates having to use any integral switch motor relays, or a Frog Juicer, or any electrical toggle or slide switches to have a "live" frog since as long as the switch is aligned, and one of the point rail toes is touching it's adjacent stock rail, the frog is the same polarity, along with everything else between the two stock rails.
The disadvantages outweigh the advantages. The potential electrical problems with the Electrofrog design come from the front of the turnout where the point rails are located in the turnout's switch. If a metal wheel traveling on the stock rail (on the open switch point rail side of the switch) touches both the adjacent stock rail AND the open switch's point rail at the same time an electrical short will occur, since the entire switch assembly's polarity is determined by the closed point rail toe which is touching its adjacent closure rail. Peco minimizes this potential by designing the point toe gap on the open side of the switch to be extra large. For DC operation, since the voltages rarely run more than 12 VDC (at full-open throttle!) if an engine shorts at the switch's point rails, it may stop, or it may just jerk momentarily then continue on. However, in DCC since the constant voltage in the rails is several volts higher than 12 volts in N-scale and is usually 5 to 8 amps, when an engine shorts, it will shut down the entire power district, and if power block protection doesn't actually turn off the power, if left unnoticed the stalled engine's metal wheel plastic supporting structure can melt...WILL melt..maybe along with several plastic ties on the turnout.
Because of this quite drastic potential of the Peco Electrofrog turnouts when using them with DCC, there are quite a few videos demonstrating how, and articles telling how to make them "DCC Friendly" because as they come, they are definitely "DCC Unfrlendly" even if most users have never had problems with them running DCC. The potential is still there.
Also, since the closure rail toes are what carries the voltage to everything in the middle of the turnout, electrical continuity is dependent on that small contact being clean and unobstructed. I never trust nickel silver rails for carrying either electricity or DCC signals without a feeder, so this IMHO is a big disadvantage.
Unifrog Turnouts:Photo (2) - Peco Streamline Code 55 N Scale Unifrog Medium Turnout:
The new Peco "Unifrog" turnout is basically the same electrically as what I have been building on the bench for 30 years, and what C55 Atlas and C55 Micro Engineering have been doing the last couple of decades...that is, making isolated frog, "DCC Friendly" turnouts.
As of today (4/4/2019) the Unifrog C55 N Scale turnout is only available with Peco's "medium" turnout. Small and large Peco Streamline Code 55 N scale turnouts are still Electrofrogs, at least as far as the Peco website is concerned. Incidentally, the photo at the Peco website illustrating the new Unifrog Medium turnouts is wrong, having only the gap on the back of the frog, and no gap at the front of the frog.
The huge difference between the Electrofrog and the Unifrog turnouts is that with the Unifrog turnout, there are only two components on the turnout that can be made to change polarity, the (a) frog and the (b) frog wing rails. The point rails and the closure rails all stay the same polarity as their adjacent stock rails...constantly, and they are connected using wire feeders, or "droppers" as the British call them. The through rails (or "frog rails" as they're sometimes called) are also fed with wire feeders to make them constantly the correct polarity. This means that all of the rails are constantly the correct polarity and are live, except the frog and the frog wing rails, which means if your engine's extra wide, thick-flanged wheels brush the open point rail toe as they goes by, it won't short, since both the point rails and the closure rails are the same polarity as the adjacent stock rail.
Frankly, I don't see hardly any possibility of a short at the frog either, so I would say that rumors about that are spurious unless somebody has wired their Unifrog turnout's frog the wrong way. The only valid problems I found online were with HO scale Peco Insulfrogs...with metal wheels that are wide which short on the back of the frog...but the N-scale Insulfrogs frog is differently constructed and doesn't have that problem. On the N-scale code 55 Unifrog turnout, if you've got REALLY thick flanges or your wheelsets are very out of gauge (narrow) you just might have a problem at the front of the frog where the frog wing rails bend and are gapped, and turn into closure rails, but I highly doubt it. To totally eliminate any problem here, Peco should have gapped the frog another tie space forward as the closure rails are beginning to diverge, rather than at their narrowest position.
Also, on the Unifrog turnouts, you don't need insulated rail joiners on the two through rails (frog rails/point rails whatever) like you do using Electrofrog turnouts, since the through rails will always be the same polarity as the rails they will attach to.
Not having to use two big ol' ugly plastic insulated joiners on the through rails of every turnout more than makes up for the small, black, plastic-filled gaps on the Unifrog turnouts IMO.
On the medium sized Unifrog turnouts, the frog is short enough that dead frogs may work with your small wheelbased motive power...maybe. I run B-B trucked Key Imports Alco S3's without any hesitation through my two dead-frog ME #6's at Echo.
However for live frogs, you'll have to power the frogs independently, which will add to the complexity. I'll let you figure that out.
Conclusion:In conclusion, unless you're going to find old stock where you are buying your turnouts, you're stuck with Unifrog Medium turnouts, which is a good thing. Small and large turnouts are going to be Electrofrogs, as is every other turnout (curved, three-way, slip, double-slip) from Peco.
If I were doing it and was going to run DCC, I would definitely find out how to make your Electrofrogs "DCC Friendly" 'cause I've had a couple of Kato F-3's melt their truck sideframes on a friend's module without "DCC Friendly" turnouts no matter if some people think the term is "erroneous". All I know is that the truck cooking didn't happen until he converted to DCC and left his old, unfriendly turnouts on his module.
The proper way to cut gaps on your turnouts before you install them, is to use a jeweler's saw, with fine toothed blades. I would highly discourage the use of a Dremel to do this job unless the turnout is already installed. Learn how to do this by watching this video at the Fast Tracks website here:
https://www.handlaidtrack.com/FTV-Turnouts-12 If you don't have a jeweler's saw or blades already, you can get both at the Fast Tracks website here:
https://www.handlaidtrack.com/tl-0043 and here:
https://www.handlaidtrack.com/36-480Photo (3) - Gaps cut in my hand-built turnouts on the bench using a jeweler's saw with a fine blade:
I think that about does it.
Cheerio!
Bob Gilmore
