Don, Your symptoms indicate that the crossover is not wired as Bob and I described. Can you remove the crossover from the layout and test it with wiring as described?
Before I add any more to the confusion, please note that a single line is used in the drawing to represent the two rails. Also, please refer to earlier drawings in this string and note that we never plan on running DC and DCC at the same time. We designed it with DPDT switches to enable us to switch between either using 3 DC power supplies (a separate one for each level) or a single DCC controller (Digitrax Zephyr), so that we could have either a DC session or a DCC session. It may not be practical to wire the level that contains the double crossover in a way that uses the cross over rout with DC operations. However, we do need to use the crossover in DCC operations. When we go "straight through" and do not use the cross over position on the double crossover, everything works perfectly, in either DC or DCC, as presently wired. (See illustration.)
If your crossover was wired this way, you DC or DCC locos would be able to use the crossover going both straight and crossing-over. Unfortunately this also requires the auto-reversing units on the outside loops for DCC and manual DC reversing on the outside loops (no continuous DC running on this level). It seems like it should be possible to wire the crossover section of track your current way for DC and with the polarity as described for DCC, with the appropriate switch(s). Another option would be to remove the crossover and add a single reversing siding so that the trains could be turned and head forward off this level. Bob
Since the entire problem seems to be with the double crossover, I think it needs to be separated from the layout for proper testing. This first picture is how I believe it should be wired (just the red and blue lines) and then tested: This second picture shows a different wiring and I believe it would cause a the symptoms that have been mentioned. I would suggest wiring it this way and testing: Please let us know if you can test the crossover without the rest of the layout involved.
I'd rather not have to tear out the crossover yet. I have another (pre-owned) double crossover that I can play with. Should it behave the same whether switched by hand or with a Kato remote switch control?
is it also a Kato 20-210?, if it is the same brand and model, then it should work the same. I do not own one so I cannot do the testing. The testing is simply to run power to all 8 end rails and then test a locomotive going straight and crossing over. Does not matter if the test is DC or DCC.
In this diagram, it appears that 4 feed-wires are going to the cross-over from the same power-buss-wires with no intervening block-control-switches. This makes the cross-over section of track one fix-phased-track-block. When these feed-wires are direct-connected so that a DC loco can continuously run the loop but not go over the crossover, there will always be a problem using the crossover path (DC or DCC makes no difference in this case)! I do not see anything that would lead me to suspect that the problem is with the crossover itself. Bob
That is correct. Four feed-wires are going to the cross-over from the same power bus wires. However, notice that these feeders go to 4 separate isolated blocks of track, because the double-crossover is split down the middle. Its two sides are from each other.
The same polarity. I think that is born out by the fact that it works in the straight through position.
And that is what prevents the use of the crossovers if you swap the wires on the lower half you should find that straight thru and crossover both work. after that we can address the reversing sections
Paul, I'm not understanding what you mean by swapping the wires on the lower half. Wouldn't that be putting one polarity on the lead trucks of the loco and the opposite polarity on the trailing trucks as the loco passed over the insulated track joiners?
Don, That is why I am suggesting to do this independent of th layout. Have you hooked up a switch (dpdt) for DC reversing loops or installed an auto reversing module for DCC yet?
Don, I believe that the way I am suggesting wiring the double crossover is the only way that will allow the use of the crossovers. The way you have it setup at this time, you pretty much have a dogbone layout on this layer with no reversing loops involved. Once you decide to wire it so that you can crossover, you will have to implement the reversing loop mechanisms.
Thanks for being so patient, Paul. I haven't had a chance yet to play with my spare used crossover or to get back to the layout in question. I've added small circles to clarify the difference between electrical crossing and connection points. Now, for the time being, ignore the wire from the DPDT switch that would connect the "DC" terminals of the switches to the power bus. IE. the layout would be wired for DCC only. That being said, do I have all of the wires connected correctly for DCC operation? If not, which connections do I need to change?
I run DCC. Its been almost 3 years...but...I just checked. The top track...coming into the X Over...the top rail is (red) ...the bottom rail of same track is (black). The bottom track is wired the same...the top rail is (red) ...the bottom rail of same track is (black). I wire a short piece of Unitrack...with feeders...before and after the double crossover on each track. This feeds the double crossover from both ends. Not sure how to wire it for combination DC/DCC...let alone 2 reversing loops
Actually, this only becomes a reverse loop situation when the cross-over switch is set to cross over. In the straight-through position, the mainline is a simple oval, squeezed to ALMOST touch in the middle. Why am I still so baffled?
Take your thumb and one finger, pretend that you hand is forward moving train, and the thumb is getting the positive-DC. Now you present layout wiring keeps the outside rail of the loop the same polarity. You hand will move around the loop with the thumb always on either the inside or outside rail as long as you travel straight across the crossover. But when you use the crossover to cross over to the other side, the position of your thumb and finger are reversed on the two rails. I have actually done this with a DC loco and it was moving fast enough to make it across, but it immediately reversed direction because the + DC changed form one rail-wheel-motor-connection to the other. You need to be able to understand this concept; it is the first step in the wiring of a layout, either DC or DCC. Hang in there; we all have trouble at one time or another making the right wiring connections. Bob
Don, The attached diagram represents the wiring required for DCC to be able to utilize the crossover functionality. I happen to use the PSX-ARs on my system but they can be be replaced with any auto-reverser product. For the blue section, it is important that the wiring be as indicated other wise you would not be able to run trains thruough the double crossover when thrown. For DC operation, you would replace the PSX-ARs with DPDT switches and you would need a DPDT for the blue section (feed all the Pos together and all the Neg together to the center poles on the DPDT). The ramp down to level two should be part of the right hand reversing loop so that you do not need to worry about matching polarity with level rwo. I hope this helps and if you have any questions about it, just ask away.
