DCC-Friendly Double Slip Wiring

[jimsabol]

Preamble: Guys I thought I knew how to wire a double slip but I keep seeing cryptic references to DCC-friendly wiring for same, and I'm starting to have doubts that I know what I'm doing.  I thought it was a simple matter of fully insulating the frog, but: stupid me!  Poser: Assuming a double slip in O scale--scratch-built from rail, not Walthers, not Shinohara nor any other commercial make, frog all rail, not plastic, insulated  (from each other) point rails, of course--is there some special way of wiring a double slip?  Problem: The big gun on DCC wiring--Allan Gartner's website "Wiring for DCC" says "Most modelers and clubs will not allow the use of double-slip turnouts because of  . . . problems" and " . . . do not try to run a reverse loop through the double-slip."  Also: a guy at the O Scale National a couple of years ago did a clinic on this topic. I wasn't present and asked him via e-mail if he could send me a copy of his diagram or, better yet, submit it to O Scale Trains Magazine; said he'd think about it; never heard any more.  Plea: Help, anyone!  Postscript: If you can find the time to answer, please include your idea of whether the frog should be powered and tell us what's up with the reverse loop prohibition.  Jim here.

[JulesB]

Go to Fastracks.com website and log onto their forums. Somewhere in there you will find a diagram to wire double slip swithes. They also make a jig to make those turnouts. Wath the video if you choose to.

Jules

 

[jimsabol]

Thanks, Jules.  I'll check Fastracks.  Jim here.

[tomikawaTT]

Everybody treats wiring a double slip as if it were some arcane experiment in Boolean algebra.  Actually, it is exactly the same as wiring two ordinary turnouts laid with their points almost in contact.

If the acute-angle frogs are hot, they must be wired to the switch thrower (machine or electrical switch) contacts for the device that moves all four points at the far end of the double slip.  If they are electrically dead, no problem.

Now, draw a line from one acute-angle frog point to the other.  Assuming you have put isolating gaps in the frog approach rails, and that your points are electrically dead when open, everything to one side of that line (obtuse-angle frog and both curved rails) is a single electrical unit and can be powered through a single feeder.  If your points AREN'T dead, make sure that the acute-angle frog gaps are beyond the sharp ends of the points.

I have built a fair number of double slips over the last forty years, without any of them ever giving me any problems.  They aren't as complicated as they appear at first glance.

Chuck (modeling Central Japan in September, 1964)

[gandydancer19]

"DCC friendly" usually refers to how close the backs of the point closier rails are when open, to the backs of any wheels (flanges) going through the turnout or points (riding on the stock rails) and causing a short as the equipment passes through.  You will have the same wiring to do for a DC system or a DCC system. (two rail track)

If you can't find any good information that you are looking for, draw a BIG diagram of your doubleslip and show each rail as it is either connected to something else or insulated. Draw it in a neutral configuration, that is, inbetween being thrown one way or the other.  Make a couple of copies that you can draw on, then just fiddle with it. You might also want to think "crossing" for some wiring help. Chances are you are going to wind up using some relays and possibly a diode matrix to control the relays, through toggle switches.

As to the reversing loop, don't wire it into the doubleslip. Make the doubleslip as one block and the reversing loop as a separate block. I think you may have a better chance of understanding it that way.

[jimsabol]

Chuck and Gandy Dancer: thanks for the lucid comments.  Jim here.

[JulesB]

Look here.

http://www.handlaidtrack.com/forums/viewtopic.php?f=4&t=809

 

 

[jimsabol]

Jules, thanks for the hint.  Unfortunately something called MSN Search Team blocked me from the site, fearing somthing called "Malware."  I'll try later.