O Scale Switch and Track Wiring DCC and MRC 2000greenspun.com : LUSENET : Wiring for DCC : One Thread
I have an O scale layout in the making and will be using Old Pullman switches which may or may not be DCC friendly. Outer rails are independent of the points, frog and closure rails which are a single connected entity. How should the switches be gapped and wired individually, in a three way and in single and double crossovers?? The same question holds for tracks connecting with the switch set ups. The layout is 22 by 27 around the walls, has 35 switches, about 500 feet of track, one wye, a turntable and will be using the MRC 2000 for control. Will be using 12 ga single strand for the buss lines and 16 or 18 ga single strand for the feeders. It is time to start laying track and doing the wiring, however, my knowledge of wiirng in DCC is nil. All track, switches, wire and the MRC 2000 is on hand. Started putting the layout together in 1983 before retiring and it would seem wise to ask for guidance. Appreciate any help someone may be willing to offer.
-- Allen G. Mews (firstname.lastname@example.org), February 19, 2001
I'm not sure how your question ended up in the MRC section! Oh, well. I'll move it one of these days - if I ever find the time to go through this Q&A forum and clean it up. Anyone want a job???
I couldn't answer your question before, because I was not familar with Old Pullman switches. Evidently, neither was any of the other excellent people who often answer questions on this forum.
Now that you have sent me a drawing, IF I AM UNDERSTANDING your words and drawing correctly, what you basically have is a Walthers/Shinohara turnout. Since you are into O scale, making this turnout DCC friendly should be very easy. Just follow the instructions for the Walthers/Shinohara.
Note that my drawings on my web page, except for insulated frogs, don't show anything that is non conducting.
If your hinge mechanism for the points and the throwbar are already nonconducting, that your turnout is almost DCC friendly and even easier than the Walthers/Shinohara! Just isolate your frog and make the electrical connections shown for an Atlas in my web page or the drawing I show for the first type of DCC friendly turnout.
If you want to make a single or double crossover from 4 of these Old Pullman switches, you could the Atlas/"first type" of turnout from my web page.
I can't answer your three-way question. Do you have an Old Pullman 3way? Don't worry answering because with me physically having one of these turnouts and very possibly having to do a "destructive analysis" on it, I probably wouldn't be able to help you. Not even a photo can help me.
Note to all: One of the the reasons a Walther/Shinohara has not appeared in my web page is because after analyzing one I did have, I determined that it was unclear how the turnout was internally making all it's electrical connections. I would have to take one apart to be sure. Someone has since given me a turnout I can ruin to make this determination. All could still be a waste of time. The soldering surgery would definitely require a resistance soldering iron and the person doing the work would have to be an excellent solderer. My page seeks to help the person who knows absolutely nothing about electricity and wants bulletproof help. What would have to be done to a Walthers/Shinohara 3way is probably well beyond their ability and would be so delicate and tricky, the people who read my page and think I'm a nut would be convinced beyond any shadow of doubt if I recommended people try to make a Walth/Shin 3way DCC friendly!
To answer your last question. #12 for buses should be okay. I'd use the #16 for the feeders. I would think #18 would be okay if you really wanted to and you are using quality locomotives that won't draw more than about 2 amps. Keep your feeders short - about 6".
Remember! The ultimate test for adequacy of wiring is whether placing a quarter on the tracks at every point causes the auto shutdown in your booster to immediately trigger.
-- Allan Gartner (WiringForDCC@augustmail.com), March 23, 2001.
Old pullman has been taken over by someone who made a good product great.
Upon receipt of three 1st class stamps they will send you their catalog which has a sketch on how to make the old pullman turnouts DCC friendly.
Basicly it involves isolating the frog and installing a jumper wire from each insulated point to it's stock rail.
The new turnouts are very nicly done w/smaller ties and better gauge.
-- tom thorpe (email@example.com), November 12, 2004.