Demonic Double slip Switch~Help Bob or anyone that can help

[Fred Bear]

Hmm, wonder why a guy like me didn't think of that one! Thanks Bob, I'll power test that one this a.m. Jake

[lionelsoni]

The shay's wheels must not be providing a conductive path between the outside rails.  Perhaps it has traction tires that insulate the wheels on one side.  The fix is pretty simple:  Just move the control rails or lengthen them so that they begin farther from the slipswitch.  Then the tender will throw it before the locomotive gets there.

[Fred Bear]

The good news is the switches work perfectly! However, when running the 4 truck MTH Shay through it, the engine does not switch, but the tender wants to, causing a pretty impressive derailment, complete with a fair amount of sparks & other neat things.

The MTH Climax runs through it like a champ, flopping back and forth as if it were made to do that.

The Blue Comet? No go, stalls on the switch.  I need to get up on the layout where the double slip is and see if the wheels are tripping the switch. First couple of times it just stayed on the outside loop. If it's on the inside loop and approaches for a switch to the outside, no problem. However, it doesn't like to switch from outside to in. So...the switch is a success, a wonderful item the way it works. I'd say with conventional trains it would be a killer. Those outside two loops however are the only ones with curves big enough to accomodate the 4 Truck Shay. Oh well, things were fun, it might be possible yet. Jake

[Fred Bear]

Can't wait to try this now, but it's going to have to wait until Friday! Fly fishing tomorrow, I'll return tomorrow evening and jump on this Friday unless I can't hold off and end up getting in to it tomorrow evening ( most likely scenario! ). Thanks again Bob, much appreciation, Jake

[lionelsoni]

If any of the rails in the slipswitch do not get connected up to terminals U or A by virtue of their attachment to the abutting tracks, you need to provide that connection by adding wires.

We're very close, I think.  As I understand it, you are victorious over the forces of darkness with the transformer's terminal B connected to the middle terminals of both switch machines.  So the next thing is to reintroduce the capacitive-discharge circuit.  So now the transformer's terminal B will not connect to the switch machines.  Instead it will connect to the anode of the diode.  The cathode of the diode (the striped end) will connect to one end of the resistor.  The other end of the resistor will connect to the positive end of the capacitor.  The negative end of the capacitor will connect to terminal U of the transformer.  And the middle terminal of both switch machines will now connect to the positive terminal of the capacitor.

If you hook all this up correctly and it doesn't work or trips the circuit breaker, the most likely reason is that you zotted the diode earlier--it's the most vulnerable component.  You said earlier that you tested the diode and that it seemed to conduct.  Well, if you reverse the leads on your ohmmeter, it shouldn't conduct much at all.  So a good diode will give very different readings depending on which ohmmeter leads you connect to which end of the diode.  If it reads the same both ways, it is toast.

Of course you don't have to run a separate wire from the negative terminal of the capacitor all the way back to the transformer.  You can just connect it to one of the outside rails (not a control rail!) at a convenient place near the slipswitch.

[Fred Bear]

OK, I did not cut anymore track, but here's what I did. I wired the U post to the rails on the outside of the cut on the right side of the switch, using the outer most rails.( I cut the switch and some rail seperate from the rest of the layout on both ends of the switch, all four outside rails of the right side of the switch, left side too as far as that goes). Next, I hooked up B terminal to the two middle post on each switch. When running a car over the " cut ", it activates the switch nicely, does the same for both sides. One cannot use it this way though as you well know, it would burn out the switch in no time.

So....as far as this goes now, the switch works perfectly, but the diode, resistor and capacitor are not hooked up. If there was just a way now to shoot some voltage into those switches, or rob the ground and activiate it with the train wheels! So close, so close! Jake

[Fred Bear]

One more question. We are putting the U post to the non control rails, but I cut the rails somewhat back from the switch, and then back again another 12 inches or so. Do the outside rails within the switch get wired also? Thanks Bob, Jake

I took the capacitor out of the situation and I'm controlling the rails as you described, B is running the switch machines.

[lionelsoni]

But are the control rails now completely insulated from the rest of the track?

Yes, when we are finished, the positive end of the capacitor should go to the middle terminal of each switch machine.  However, for now, it would be better to put the capacitor circuit aside and connect the transformer terminal B directly to those middle terminals until we get the control rails sorted out.

(I am assuming that you are okay with using transformer terminal A for the track voltage--center rail--and transformer terminal B to power the switch machines.  If you plan to use a different arrangement, let me know so that I can describe the connections the way you will use them.  In any case, terminal U must go to all the outside rails that are not control rails.)

There will be voltage across the diode all the time.  There will be voltage across the resistor while the capacitor is recharging.  There will be voltage across the capacitor after it recharges.

 

[Fred Bear]

Do you think the control rails are the problem then? I understand NOT to use two rails on the same track.

One other question. Do you think there should be a lead from the capacitor + to each middle post on each switch? Thanks Bob, Jake

Bob, just curious, when this is all wired up and hot, will there be voltage across the diode, resistor and capacitor all the time?

[lionelsoni]

Well, there's one problem.  You made the right number of cuts, but in the wrong places.

An insulated control rail should be insulated from all the other rails; so you need two cuts to make one control rail.  (But you can use a rail joint between the slipswitch and the track leading to it, with an insulating track pin, if that's convenient.  Think of it as a cut that is already made for you.)

The other part of the problem is that you apparently made two control rails side-by-side in the same part of the track.  This won't work, because the idea of the control rail is that the wheels and axles are supposed to connect it to the regular rail on the other side of the track, that is, the rail that is connected to the transformer's U terminal.  So there should be only one control rail in each track leading to the slipswitch.

I assumed that you wanted this thing to work when a train came through from any of the four possible directions.  If trains are coming only from the right, then you don't need the two control rails that would be in the tracks on the left.  However, if you do include those control rails, the only cost will be the two pieces of wire to connect them up, and you will be all set if you ever run a train the other way.

[Fred Bear]

My insulated track pieces are only single cut. In other words, I cut the track around the switches only once per rail. so I made 8 cuts total. There is NOT a small section of track completely free of the layout. Should there be two pieces free of the entire layout for control rails? Jake

[Fred Bear]

Bob, if you think a phone conversation would clear this up, feel free to call me collect at 304-843-1740. Thanks, Jerry

[Fred Bear]

This worked exactly as you described. Not to jump the gun here, but I nearly had the thing working. It would work perfectly with one incoming train. I had it wired as we described, the insulated rails were connected to each two wires of the outside terminals. If we call each post on the switch, 1,2,3, the 1's and the 3's were wired together, and the 1's were going to one set of control rails and the 3's to the other.

I think these next two questions are paramount. One, if you are looking at the switch in front of you, with the trains running right to left, should anything be wired on the insulated track over on the left hand side of the switch? I have the insulated control rails on the outside loop, using the outside rail, wired back to the 1's on the switch. I have the outside rail on the inside loop, wired back to the 3's. Is that correct?

Next question. Should there be a wired running from the + side of the capacitor to EACH middle terminal of both switches? The fact that one side of this switch throws should indicate I'm very close.Now, if I take the wires off the side that works and hook them up to the side that doesn't work, they work. But when BOTH are wired up, neither will work. I have done something wrong I'm sure. I'm also blowing components because of have 400 bare wires hanging everywhere I need to remedy next go round. I bought plenty of components, there were fairly cheap.

So if you look at this thing as a big X, with a break at the end of each X for the insulated rails, where in the heck do the wires coming from U post go, and where do the wires coming from the outside terminals of the switch go? Are we dealing with only one side of this switch for wiring? Do all 8 cut rails need wired? Trains are only coming from one direction, so I'm trying to get the right hand side of this switch to throw as each approaches. Bob,thanks for your patience, sorry I cannot grasp this any better than I am. Jake

[lionelsoni]

Let's try to simplify this setup.  This is not what you would want eventually; but it might help us to find the problem by putting things into the circuit one-by-one:

Connect ZW-U to all the outside rails, except for insulated control rails.  Connect ZW-A to all the center rails.  Connect ZW-B to the center terminal of both switch machines.  Leave everything else not connected.  Turn up the transformer controls.  Then connect a test wire to one of the outside rails, the ones that are all connected to ZW-U.  Touch that wire briefly to each of the other, unconnected terminals of each switch machine.  You should be able to operate each switch machine each way by doing this.

Then disconnect the test wire and reconnect it to one of the insulated control rails.  Try touching each of the other, unconnected terminals of each switch machine just like you did before.  Nothing should happen.  Then repeat this test with the wire connected instead to each of the other three insulated control rails.  Nothing should happen.

Let us know what happened in these tests.

 

[Fred Bear]

One other thing, I cut all 8 rails associated with this mess, the two outside rails on both incoming and outgoing loops. The inside or power supply rail was left intact. Jake

[Fred Bear]

OK, almost had it, now none of it will work. I trip the breaker on the transformer somehow, what do you think I cooked in the way of elements? I tested the diode, resistor and capacitor for continuity, all seemed OK.

Here is what I wired

Power to Diode to resistor to + Capacitor, then a wire from the + side of the capacitor to each middle terminal on both switches.

The U post from the tranny went to the outside rail on the right side of both incoming loops with track still connected to the switch, so not the insulated track., so two connections there, one to each rail on the outmost side. The insulated rail was connected to both terminals on the outside of each switch, and the other insulated rail received the other two wires from the say, inside terminals of the switch. No wires were connected to the insulated rails on the left side of X, only the right side. What have I done wrong? It would work and toss the switch to accomodate a train one way, but would not switch back, without me taking the wires off one side that work and putting them on the other side. Now I'm back to square one! Help! Jake