Being "electrically challenged" I am having a problem using my old Shinohara turnouts. My son, the electrician, says I need to cut gaps because my trackage keeps changing polarity. OK so where do I cut these gaps?
I don't believe that pre-1980 has much to do with it. I think they still make them the same way unless you buy a Walthers/Shinohara which says DCC friendly on the box. Here are a couple links that might by helpful to you:
http://www.proto87.com/making-rtr-turnouts-dcc-friendly.html
http://www.proto87.com/turnout-wiring-for-DCC.html
http://www.wiringfordcc.com/switches.htm
Both rails that diverge from the frog must be insulated because the frog and diverging rails change polarity according to which way the turnout is set.. Then you'll need separate power feeder wires beyond the insulated rail joiners.
So if I understand you correctly, I cut a gap just above the frog itself in the diverging rails; that part I think I understand (electrically challenged remember). I have two power feeders about two feet above the turnout....should that be sufficient; and also do I need to fill the gap with anything? I am currently using DC but may (depending on budget issues) switch to DCC at a later date.
I'm not sure about your terminology when you say "above the frog." The gaps should be cut at or near the rail joiners or those joiners should be plastic ones instead of metal. If you can remove the turnout, just change from metal or plastic rail joiners on both rails.
I'm not sure if I can remove them but I could use a Dremel tool and cut through the rail joiners. Would that be sufficient? However, if I do that what keeps the locomotive running with power to just one rail of the turnout?
BobL609 I'm not sure if I can remove them but I could use a Dremel tool and cut through the rail joiners. Would that be sufficient? However, if I do that what keeps the locomotive running with power to just one rail of the turnout?
I believe that a lot of what you are asking is explained on the links I gave you above.
[quote user="maxman"]
BobL609: I'm not sure if I can remove them but I could use a Dremel tool and cut through the rail joiners. Would that be sufficient? However, if I do that what keeps the locomotive running with power to just one rail of the turnout?
With all due respect, the links you gave me all relate to DCC operation; I am not operating DCC but rather DC. That could be part of the confusion on my part...are the concepts the same?
Yes, the concepts are the same. A short is a short in DC or DCC. Modifying the turnouts per the information on the Wiring for DCC site will make them more reliable for both DC and DCC.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
[quote user="BobL609"]
maxman BobL609: I'm not sure if I can remove them but I could use a Dremel tool and cut through the rail joiners. Would that be sufficient? However, if I do that what keeps the locomotive running with power to just one rail of the turnout? I believe that a lot of what you are asking is explained on the links I gave you above. With all due respect, the links you gave me all relate to DCC operation; I am not operating DCC but rather DC. That could be part of the confusion on my part...are the concepts the same?
Yes, I know you're running DC, but I believe that in one of your posts you mentioned possibly converting to DCC. Being that as it may, as Randy says the concepts are the same.
Anyhow, there was another thread on this subject not that long ago that included a sketch showing where the gaps are supposed to go. It is here: http://cs.trains.com/TRCCS/forums/t/188321.aspx.
You will note that there are several differences mechanically between the turnout shown in the sketch and the one you have. First, there are gaps on the frog rails, both before and after the frog. This isolates the frog electrically from the rest of the turnout. Isolated means that there is no electrical path from any of the turnout rails to the frog, so the frog is unpowered as the turnout sits there. This is normally not an issue unless you are running very short wheelbase engines or engines that have limited electrical pickups at the wheels. Most people will find a way to power the frog. One method to do this is to use electrical contacts on the switch machines to power the frog as appropriate to the direction that the points are thrown.
Second, if you look at your turnout you'll see that there are two metal bridles or connectors at the point assembly. The first is at the throw bar, and the second is at the point where the points pivot. If you notice on the sketch the second bridle does not exist and the point rails join the closure rails with rail joiners (the closure rails are the rails that go from the end of the moving point to the frog).
Although the throwbar is not shown on the sketch, the metal bridle at that point is replaced with a plastic, non-conducting piece on a so-called DCC friendly turnout. I have some Shinohara code 83 turnouts which had the metal bridle, and I replaced this bridle with a throwbar made of circuit board material. It is necessary to cut a gap in the board cladding between the two point rails to eliminate a circuit between them.
The purpose of this bridle replacement exercise is to have the point rails have the same polarity as their adjacent stock rails.
Anyway, all that explanation is probably more than you initially wanted to know. So what you need to do is to have insulators, or gaps, located as shown on the sketch where it says insulated joiners.
And to answer the how does it operate with only one rail powered, it won't if you isolate the frog unless you have power to the frog as shown where it says power routing switch mechanically connected to points. If you don't isolate the frog, then the frog is powered by contact between the point rail and the stock rail it is against. If the points are thrown to the other side, then the frog polarity is automatically changed.
Just be aware that if you eventually switch to DCC you could potentially have problems with certain engines in certain conditions if you don't make the other modifications I mentioned.
I hope this is helpful and not more confusing.
Regards
I like to point those who don't understand power routing turnouts to the set of diagrams at http://www.proto87.com/turnout-wiring-for-DCC.html. As has been said, the principles of turnout wiring are the same for both DC and DCC. DC happens to be a little more tolerant of momentary short circuits that shut a DCC layout down. But momentary short circuits are not a good thing in DC either.
Your Shinohara turnouts are called power routing as they are made, and follow the wiring conventions in picture #4. The insulating gaps are needed at Y when ever there is a power feed to the track beyond Y in the picture. If one branch ends in a spur with no power feed, the gap at Y is not needed for that path. The turnout will route power to the spur only when the turnout is thrown for that path. Hence the name "power routing".
In DC operation, the potential short circuits at X in picture #4 are rarely a problem. Even with DCC, 80% or more of the Shinohara turnouts will never give you a problem.
For DC, the 1st step towards increased reliability has been to add a frog polarity contact so that if the points do not make good contact to with the stock rail, there is still power to the entire turnout. This contact is shown in picture #6, although your points still remain wired as in #4.
Changing the points to #6 means cutting and replacing the metal straps that link the 2 points, as detailed in a previous post. This is a fair amount of work, and I would not go there unless I was using DCC and experiencing short circuit problems at X.
hope this helps
Fred W
I thank you all for your assistance and patience. I am not a "concept" type person; I need to see a picture and have someone point at it and say "do this dummy". I'm thinking that converting to DCC might be easier if I just rebuild the enter layout. Again, thank you all for your assistance; I'm off to buy a cut off wheel for my Dremel.
BobL609 I am not a "concept" type person; I need to see a picture and have someone point at it and say "do this dummy".
I am not a "concept" type person; I need to see a picture and have someone point at it and say "do this dummy".
You, also? There's a lot of that going around. I need a picture, a bat, and someone to swing the bat at my head to get my attention!
rrinker Yes, the concepts are the same. A short is a short in DC or DCC. Modifying the turnouts per the information on the Wiring for DCC site will make them more reliable for both DC and DCC. --Randy
Well, it's a little shorter in DC than DCC...
(Just kidding :-)
John
Yeah but DCC packs a bigger punch