This post is to help you guys wire up a double crossover with live frogs. This does NOT apply to walthers as they insulate their frogs (I personally dislike insulated frogs as it leads to stalling locos)...But this diagram should help with homemade track, like fast tracks.
In the diagram above red wires = track 1 and black wires = track 2The purple box (bottom center) is a DPDT 12V relay switch commonly available at mouser on the cheap. (I recommend you pick one out with at least 3 amps capability)
Edit:If your polarity comes out backwards for frogs 1 & 3, just flip wires 2, 3 on tortoise 1If your polarity comes out backwards for frogs 4 & 6, just flip wires on 2, 3 on tortoise 2.If your polarity comes out backwards on frogs 2 & 5, switch the center output on each side to attach to the opposite frog (move wire from frog 2 to frog 5, and from frog 5 to frog 2)
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Why 2 toggles? Can't you switch between "straight" and "crossed" with just one.
It would also help if you would indicate which points are thrown by which Tortoise.
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carl425 Why 2 toggles? Can't you switch between "straight" and "crossed" with just one. It would also help if you would indicate which points are thrown by which Tortoise.
Why 2? This is wired up for tortoise. A single cross over requires at least 1 tortoise. This is a double, so two are required.there are two throw bars. the left throwbar is attached to tortoise #1. The right throwbar is attached to tortoise #2.
this leads to 4 possible combinations:
DPDT switch 1 DPDT switch 2 Expected Track Movement
Up Up Bottom Track pass through. Top track invalid
Up Down Cross Top Upper left to Bottom lower right
Down Down Top Track pass through. Bottom track invalid
Down Up Cross from lower left to upper rightIf you want to use 4 tortoises (4 throwbars) so both tracks can pass through at the same time, let me know.Also I can show you how to wire it up to a 4 position rotary knob since only 1 route is valid at a time. (top pass through, upper left to lower right, left left to upper right, and bottom pass through)
DigitalGriffinWhy 2? This is wired up for tortoise. A single cross over requires at least 1 tortoise. This is a double, so two are required.
You can switch 2 or 4 Tortoises with only one toggle. You really only need 2 options - both straight or both crossed.
If you need one of the routes crossed, it doesn't hurt anything that the other is crossed so why not throw them both at once with the same switch?
What Carl said. Sure it's a 'double' crossover, but there are really only 2 valid settings: both routes straight or both routes crossing. Setting one to cross and one to straight will result in a derailment from running a switch or a collision as one train crosses over and runs into the one on the straight.
The easy and obvious option is 4 Tortoises, one per set of points. But Tortoises are expensive, and the flexibility to set each point differently is not needed. Two is fairly easy to figure out mechanically. You actually can do all 4 with just one Tortoise, but that requires some complex linkage to get everything to move in the right direction and the cost of one more Tortoise may not be worth it in terms of your time in building and adjusting a complex linkage.
The relay is a good idea. PREVENT shorts instead of detecting them and adjusting after things short out, as happens with autoreversers and frog juicers. 1ms response time or not, it's still allowing a short. Change the frog polarity as the points are moved, and there never is a short.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
DigitalGriffinHow do you know which is valid without knowing the route?
Ah... good question! I think I would be inclined to use some other form of automation based on occupancy detection or auto reversers.
If I only had toggles to work with, I think I would use one to control crossed or not, and the second to choose the route for frog powering when crossed. You would only have to worry about switch 2 when you wanted to cross. Label the two poles on the switch as "/" and "\". This would probably be less complicated for operation than lookuping up the solution on a matrix.
If nothing else, you've convinced me that I'm lucky I don't need a double crossover on my layout. Fortunately for me, the N&W had none on the section of line I am attempting to represent with my layout.
OTOH, making something like this work would be a cool feature to show off to visitors.
DigitalGriffin(I personally dislike insulated frogs as it leads to stalling locos)...But this diagram should help with homemade track, like fast tracks.
You can also just leave the frog gapped. Make it 3/4" or less in length. This should be sufficient. I took measurements between power pick up locations, and found that the shortest distances were between 15/16ths inch to 1" (Bachmann 44ton and Bachmann 4-4-0). As long as your dead sections are less than these measurements you shouldnt have problems. If you do then you may have broken pick up wires. I use insulfrog peco turnouts with no issues in both code 83 and code 100.
You (Prototypically) cannot put all four switches on one lever because that would set up a conflicting route. Levers on LION's GRS machine are interlocked so that booth cannot be pulled at one time.
As a model, you could do it, but the LION would not. The double cross over of him is at the terminal. You would not want to display a green signal to both trains at once, now would you? Oh My! Lions and Tigers and Bears! Somebody will hang for that one, and everyone will get to pee in a cup.
LIONS are amoured of interlocking equipment, and of course the LION built his GRS machine before him learned all of the details of railroad interlocking.
Here is the interlocking bed of a real GRS mahine. Pulling a lever raises the vertical member if it is unlocked. Normally a machine such a this is returned to the normal position after the passage of a train, so most levers should be unlocked, except of course the signals, those are normally locked in the RED positon.
Pulling the lever, it will only move half way. This sends the command to the switch machine to move the points or the signals as required, and it also locks all levers whose movements would now conflict with this lever. Once the trackside equipment is fully moved and locked, it sends back a signal to the interlocking machine to allow the lever to finish its movement, thus unlocking any levers that are no longer in conflict with this one (ie a signal lever).
On a GRS machine, two switches may be moved by one lever, but it will still take up two positions on the machine frame, since each switch needs to report back independently that it is aligned and locked.
Levers point up and down alternately for no other reason than not to pinch the operator's fingers on the adjacent levers.
Here is interlocking machine and model board of said LION with layout in the background.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
carl425switch up - all turnouts normal (both routes through) switch down - all turnouts reversed (both routes crossed)
Ahem...
Normal is normally the down position, and up is normally the reverse position.
This way when the piolot enters the cockpit he can wipe all of the switches down and every thing will be in the normal position. Remember that in fighter planes, the pilot has gloved hands because there is no heat in there, and it is cold way up there.
Ok, you are not flying an F4B over Vietnam, but do you think that this design was original with the Navy (or Air Force if you are that way). Nope, this is just normal mechanical archetecture. Normal on a GRS machine is with the levers in. Normal on a US&S machine is with levers vertical. On an old armstrong machine levers pushed back towards out of the way is normal because if they were all poking you in the belly, you would not be able to reach the ones in the rear.