"DCC/DC Friendly" N-Scale Hand-Laid PCB Turnout Diagram

[robert3985]

Edit:  I've posted this a couple of other times today here at TRW and if the mods think that's not permissible please feel free to take it down.

I had one of our TRW members ask me for a link that explains exactly what a DCC Friendly PCB hand-laid turnout is and how to create the electrical turnout circuit to make it "Friendly".

After doing half an hour of Google searching, I could only find diagrams and explanations of HO and N RTR commercially available turnouts, soooo....I decided to create a diagram explaining what "DCC Friendly" means, and how to gap the rails and PCB ties to make that happen for hand-built N-scale PCB turnouts.

Also, I've known since I was a kid in the 1960's what the best way to ensure no shorts and reliable running on model railroad turnouts, but I think it's not correct to assume that every model railroader knows what a "DCC Friendly" turnout is, so I'm posting this little diagram here for those of us who build our own PCB turnouts, or those who wish to make sure their hand-made PCB turnouts are gapped correctly for electrical "Friendliness".

Note that a "DCC Friendly" turnout is also a "DC Friendly" turnout.

Photo (1) - My "DCC Friendly Turnout" captioned diagram:


Cheerio!
Bob Gilmore

[nkalanaga]

And this one might ought to be a"sticky" post, probably in at least N/Z Scale and DCC/Electronics forums!

I imagine there are a lot of people who are confused by the term "DCC Friendly".  As you said, it's also DC friendly.  I wish I'd done this with my dual-gauge turnouts, but they were built before DCC became common, and I never thought of it.

[jagged ben]

The reason it got the moniker 'DCC friendly' is that when using DC locomotives may more likely roll through the shorts and keep going, with perhaps tolerable results.  Whereas on DCC most circuit breaker functions act quickly enough to stop the loco on the short every time.  But this is a minor point that can't even be relied upon.  So yes, this is the best way, really the only way in my opinion, to build turnouts for both DC and DCC.   Thanks Bob.

[Sokramiketes]

I usually go one more PC tie on the front of the frog, as your pinch point there is the same use-case shorting scenario as the points... ie the back of a wheeset shorting against the opposite polarity.  Cutting that gap one more tie out leaves more clearance between green and red. 

[robert3985]

I usually go one more PC tie on the front of the frog, as your pinch point there is the same use-case shorting scenario as the points... ie the back of a wheeset shorting against the opposite polarity.  Cutting that gap one more tie out leaves more clearance between green and red.

@Sokramiketes - I'm doing that now too.  This photo was of an older turnout I'd constructed 15 years ago.

Even though this is a potential problem, I've never had any shorts at the frog because I make sure that any metal wheelset (either on an engine or car) is perfectly gauged before running them on my layout since I built my turnouts to a "tight" NMRA standard as far as the frog & guardrail flangeways and the Check Gauge are concerned, and if they're not perfectly gauged, they'll bounce at the frog because of the tight Check Gauge there, especially if they're narrow.

I also saw the frog gapping being one tie too "short" at the front of the frog when photoshopping this diagram, but didn't want to take the time to correct it.  I'll re-photoshop this sometime today and correct that potential problem on all of my "DCC Friendly PCB Turnout" posts.

Cheerio!
Bob Gilmore