Is it possible to run 2 trains with different speeds on loops connected by 1122 switches?
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Radioman,
Yes. But there are some contingencies. One important first question:
1.) Are you planning to run in conventional mode (via traditional transformer throttle), or via command control (using TMCC, Legacy, LionChief, or DCS remote)?
Mike
It will be conventional with a ZW. They are connected by 2 switches in each loop. They make use of the non derailing feature. John
Two switches connecting parallel track is called a "crossover," and you probably don't want to use the full non-derail feature in that situation. Instead, use a single switch control to throw both switches either "straight" or "through curve." You might then want to set up the non-derail feature only on the one side of both switches where the curve can not be accessed to avoid that potential derailment scenario.
Chuck
Ok do I need to Isolate the middle rail? How do I only use the no derail on one side? Just use manual controller for the one side? John
Radioman,
OK. With the switches set to keep the individual trains running on their own loops, and using only one ZW, this is fairly easy. Use one of the ZW's main throttles for one loop, say A-U, and another for the second loop, maybe D-U. Make sure that 'U' is connected to the outside rail of both loops and that there is an electrical break, or 'fibre' pin, in the center rail between the crossover turnouts.
The only time that a difference in voltage between the loops, i.e. different settings between the two throttles, becomes an issue is when you wish to route a train off one loop, and into the other. At that point set both throttles to approximately the same position and throw the turnout(s) to connect the loops. Once both trains have made it to their opposite loops, reset the turnouts back to physically re-isolate the loops and resume.
(This works but you'll notice however afterward that the throttles 'stick' with the loops and not the trains, i.e., A-U is now controlling the opposite train from what it was before the switchover, and the same for D-U.)
Mike
Thank you that is the info I needed. I'm used to HO and 3 rail is giving me some fits. Thanks John
My experience has been that at the junction you need three plastic pins, left, center, right. The outer pins are for the non-derailing feature for each switch, and the center pin to isolate the loop. I use command control, but it is nice to be able to cut the power to a loop, or run a conventional or PS2 engine now and then. Also some times you have a short out there somewhere, and dang where is it?
The three plastic pins will allow the switches to come apart easily, especially on a concrete floor. I solved that by using black plastic tie wraps. If you are on a a layout with plywood underneath, just screw them down.
Another possible solution is to use a small section of track between the switches, but with O gauge trains, usually you are trying to squeeze as much in as possible. Will still need three plastic pins.
The above applies to tubular track. I believe Fastrack switches have the non-derailing feature taken care of. Can't speak for MTH or Gargraves track.
Got it all working. Have 3 rails isolated between switches. Track is screwed to a platform. Also converted the switches to constant power. Will post a video later. Thanks everyone very much. John
I'm wondering because it seems logical: at the point of cross-over between inner and outer loop, when a car with metal wheels spans the connection point, what happens? The car is 'passing' different voltages thru its body, right?
- walt
@Mellow Hudson Mike posted:Radioman,
The only time that a difference in voltage between the loops, i.e. different settings between the two throttles, becomes an issue is when you wish to route a train off one loop, and into the other. At that point set both throttles to approximately the same position and throw the turnout(s) to connect the loops.
Mike
Walt,
You're quite right to raise that concern. That's specifically why I suggested setting both throttles to the approximately the same point.
The more different they are the more likely that the voltage won't be the same on both tracks. The more it's not the same the more current you'll get flowing through the car that is presently spanning the gap.
Think of a lighted passenger car with rollers on both trucks. The wire between them, inside the car, will act like a fuse unless the voltage is approximately the same on each truck, i.e., on each side of the gap.
Mike
@Mellow Hudson Mike posted:Think of a lighted passenger car with rollers on both trucks. The wire between them, inside the car, will act like a fuse unless the voltage is approximately the same on each truck, i.e., on each side of the gap.
This is the reason I put a PTC between the pickup roller connection when I do LED upgrades.
John
Glad to hear there is a new conventional controlled O gauger in the hobby.
I have a homemade 43 year old conventional controlled layout with three LW transformers and 33 remote operated Marx 1590 metal frog switches controlled by two Actionable Touch Track Diagram Control Panels.
I run two concentric loops with two sets of switches between the two loops. I use two LW transformers the main train board where as you use one ZW with two throttles.
I like to be able to run each loop on different LW and have fiber one pin to isolate the cross overs. I have added a selector switch (single pole, double throw switch) on the control panel that lets me run one transformer for each loop or use one transformer to run both loops to have one transformer run the whole layout with total of three LWs.
Here are pictures of the layout and a write-up of how I wired is on the OGR topic linked below.
https://ogrforum.com/...ra-027-layout?page=1
Main Board One on Page 1 post 8
The 1T ---2 Trans, the slide switch with the red dot ( for Red LW) and the red / Green dot is for the Red LW inner loop and Green LW for the outer loop.
My layout is more complicated now that I have added a third adjacent loop and third LW transformer so now I have one Red lighted LW run the whole layout, or two (Green and Orange) LW run two loops and the third Orange LW run the new loop or have each of three LWs run only one loop each.
New train board control panel with LW selector switch (with Green and Orange dots) shown on left of panel and Orange LW to way left
Found on page 3, post 24
You can click on the above OGR link and see how I hooked up the the LW transformers to use One LW, Two LWs or Three LWs. The topic shows (in 8 pages) how I built the layout over the last 33 years; how I made a Homemade $10 turntable, and homemade round house, log dumper, mountain and coal dumping coal mine and everything else including cars.
There is a table of contents on Page 1 post 1
Charlie
@gunrunnerjohn posted:This is the reason I put a PTC between the pickup roller connection when I do LED upgrades.
Excellent idea. It also solves the problem of the the two rollers on opposite ends of a derailing car unintentionally connecting the center rail with an outside rail.
Mike
Thanks for all the comments. I will have to check out your control panel Charlie. What size or value of PTC do you use. I have plans to use breakers in the lines to the track and for the accessories. Also will have 2 sidings controlled by toggle switches. I have had O gauge for several years but only around the Xmas tree. Decided to make a permanent(?) layout in the other half of the basement. The other half is my HO layout, both under construction. John
I use 6 Amp Circuit Breakers as described below
Each Lionel LW train transformer runs only trains and is protected with a 6 amp circuit breaker mounted below the control panel with the reset button sticking up threw the panel face. The CB's have a 18 volt light bulbs wired across the contacts and mounted below red plastic to show the light (labeled "Short") when the CB trips. The CB is reset with by pushing the red reset button on the control panel shown below at the top and labeled RESET and SHORT under the red plastic window. Each CB is about 2 inches long x 1/2 inch wide X 1 inch deep with the red reset button sticking out. Extra fast CB are not necessary for conventional control without electronic e-Units, etc. Mine will trip on most derailments and protect mainly the transformers
John
I have found the control panel with the buttons on the track on the diagram is the only reasonable way to control 33 switches. The control panel is not needed for a few switches. I also have dozens of switches for accessories, lights, isolating track sections.
You may notice the labels RELAY and OUT and IN. These are for operating the two loops (IN and OUT) with blocked sections and insulated track sections using relays to operate two trains on a loop, simultaneously, in either direction. The relay will delay the following train when it gets too close to the front train but keep a few volts on to keep from cycling the e-unit. Details in my layout write up.
PS I see your handle is Radioman77, I am into vintage 1970s stereo receivers and audio and my brother was a life time ham operator.
Charlie
Got all running here is a small video. Thanks to everyone. John
Attachments
Videos (1)
I can barely make out those are model trains, what resolution is that video? You might consider cranking up the resolution a bit. 
Getting back to the basics of the question, I think this opens some traditional conventional possibilities:
https://ogrforum.com/...lays-nor-electronics
And this:
John not sure of the resolution it is a new phone for me. First time taking video. Also I'm a luddite with this stuff. Bmoran4 ,interesting ideas will look into them a little down the road. Getting ready to take a short vacation. When I return I plan on further progress on the layout. John
gunrunnerjohn, What value PTC do you use? Digikey part # will help thanks John
@Radioman77 posted:gunrunnerjohn, What value PTC do you use? Digikey part # will help thanks John
Bel Fuse 0ZRC0025FF1E is a good choice for LED lighting in passenger cars.
The Bourns MF-R075-0-99 is a good pick for connecting in a locomotive motor lead to protect against short circuits or motor stalls. I also use these in the power leads between a locomotive and tender to protect the tether wiring.
Ok thanks will see about getting some. I have to order some other parts. John
