Crossover problems?

Hello,

I am stumped here. btw this is a DC layout.

This is the part of the layout I am trying to figure the proper way to wire for 3 Tyco locos.

All my other locos make the crossover with no trouble but the Tycos’ wheels are powered differently.

The two front left wheels are powered positive, the two rear right wheels are negative.

This causes the loco to stop halfway on point A and B.

Also, when the loco enters the Crossover going forward one rail is positive, but when it exits the Crossover the polarity reverses because on the Main Oval the new direction is reverse.

Does anyone have any suggestions on how this can be wired with on - off toggles switches ar maybe set it up as a reverse loop, although due to the polarity change, is that possible?

Thanks for any help

I know this is just an image but in Paint or another app the print is readable.

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/current_zpsg0m1ez9s.jpg

cplmckenzie

What you have there is not a crossover, but a reverse loop. Instead of a seperate power pack running that track, it should be driven from the same pack that runs the loop of track around the whole thing, and you will need to wire in an additonal reversing switch, or else use the Atlas track components and follow their wiring guides, so that as the train enters the reverse loop cutoff at A, one it is fully within the A-B section, you flip the switch which changes the polarity of the main line (everything OUTSIDE of the A-B isolated section) and then the train can smoothly exit the reverse loop connection at B. Or vice-versa.

One of the best sources for info on this, because of pictorial diagrams, is the old Linn Westcott “How to Wire Your Model Railroad” book, or any of the older layout books - HO Railroad That Grows has the wiring info in, or if you have the All Access Pass you can look up old issues, one that has complete info on wiring stuff is the one on building the Manchester & Paradise

–Randy

Good Morning (EST)

Thank you for replying. You know I was thinking the same thing. So I wired in a on-off-on DPDT switch along the same principles as my reverse loop in another part of my layout ( where both ends of the loop are completely blocked off from the main oval), but it didn’t work.

See pictures of working reverse loop here…

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_060437_zpsr2fplcoh.jpg

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_060456_zps9vtqpb8n.jpg

I believe(?) because in the diagram at point A the polarity coming from the main oval and entering the crossover(?) track is the same on both rails, but in leaving at point B the rail polarity changes as going back to the main oval the direction changes to backwards.

Also, why do all my other locos (either powered and negatives wheels being on the same truck whether front or rear) crossover with no problems.

As opposed to my Tycos’ which have the wheels wired differently. See original post for description.

cplmckenzie

btw. I see you are in PA. So am I in New Castle.

Ehh? One side of the loco should have the wheels as positive and the other side of the loco should have the wheels as negative. Your description of the Tyco locos is confusing.

Rich

Yes that is true but after throughly looking over some of the diagrams at hoseeker and actually dismantling a couple for parts, that is the way they are wired.

cplmckenzie

If all your other equipment makes it through Your reverse loop ok…why don’t You just switch the motor leads on the Tyco’s and forget about changing Your wiring…for it very well might happen that when You change the way You have it wired and the Tyco’s make it ok, all Your other engines won’t…so You are back to square one!

Generally…engines are wired right side positive when facing forward and left side negative. There have been some older Tyco engines that were wired Left pick-up positive…I know…I had some 0-4-0 Shifter’s as they were called back then and that’s how they were wired.

Good Luck! [:D]

Frank

Hello

And thanks for responding.

These are Tyco GP20s’…see images for wheel layout.

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_105153_zpstyjpfkao.jpg

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_105302_zpshpkkwtmr.jpg

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_105231_zpsiwidowq5.jpg

Also please see the .jpg in my original post for a description of my problem area, as I am not sure this is a “true” reverse loop.

Now the images in my second post is a “true” reverse loop on another part of my layout and it works fine with all my locos.

Now these are pictures of my actual problem area.

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_105951_zpsrrjezy0e.jpg

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_110011_zpsphzlheph.jpg

Thanks.

cplmckenzie

That being the case, how are the front right wheels wired and how are the rear left wheels wired?

Rich

In the diagram included in your original post, the section of track between points A and B is what I refer to as a “reversing section”. So, on your DC powered layout, you are going to need a DPDT switch to manually flip the polarities inside the reversing section.

With the DPDT correctly wired and in place, if all of your non-Tyco locomotives work correctly, then the reversing section is wired and gapped correctly. You are going to have to re-wire the power pick-up wires on the Tyco locomotives.

Rich

So, if I understand correctly the return loop where everything works you have both rails at each end of the loop gapped with insulators.

But the reverse section where there is a problem both rails at each end are not gapped. Is that correct? If so, you need to gap both ends of both rails.

Also, if I remember my reverse loop wiring, I think you need to have two dp/dt toggle switches, one for the loop and one for the rest of the railroad.

maxman raises an important point. As I mentioned in my reply, if the reversing section that fails with the Tyco locomotives works just fine with the non-Tyco locomotives, then it is wired and gapped correctly. So, Test #1 is to determine if both of your reversing sections perform flawlessly with your non-Tyco locomotives.

Rich

No all rails in both section a gapped (both rails).

Yes tested many times, all directions and the non Tycos run fine

Hey Rich,

Thank you. These pics are the best I could come up with.

These trucks came out of some Tyco loco I had to salvage. Out of 6 total I got 3 running.
I will try to explain them.

These first images are front and rear trucks. Front trucks to the left. There is a black wire coming from the rear trucks (on the right) that leads to the front trucks.

Notice the pickup wheels on the front trucks.

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_164000_zps8fhq1hyv.jpg

Now the same trucks flipped around.
Rear trucks on the left(the black wire from them can be better seen and notice the pickup wheels)

Front truck on the right (notice the non pickup wheels.

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_164041_zpsmjbdvgx7.jpg

Now these pics are from a working loco with the center weight removed. Hopefully you can make out the black wire running from rear truck to front truck

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_164556_zpsr3fh2qpf.jpg

http://i935.photobucket.com/albums/ad200/gmckenzie444cplmckenzie/IMG_20160722_164610_zpsw65mekuf.jpg

Any directions on how to rewire these is appreciated.

cplmckenzie

So, it sounds like the layout is wired and gapped correctly.

That being the case, why not follow Frank’s advice and rewire the trucks - - right side positive and left side negative?

Rich

Well, I had looked at that option a while ago because it seemed like the likely solution but.

  1. I am pretty new at this model railroading stuff, a year next month.

  2. I know you can’t make it out in the pics I posted but the design of the wheel setup, I believe presents a problem,.

On the other side of the powered wheels are non pickup wheels with gear setups, both front and rear trucks.

To make a long story short, I have no idea of where to begin to make this type of modification…uuummmm.

Let me ask a question here.

In my first .jpg post, at point B where the rail polarity changes (positive to negative and negative to positive) instead of insulating both rails I leave the (I believe) the negative rail connecting and put in an on/off toggle switch. Because at other places in my layout where I have these toggle switches, the Tycos cross with no problems.

Is that possible?

cplmckenzie

The tail end of the turnout at point A and the tail end of the turnout at point B should be gapped. A DPDT switch should control the polarities inside the reversing section and another DPDT switch should control the polarities on the main layout.

To quote a section of commentary from the azatrax web site, “On layouts with DC power, the track power connections must be swapped on the track that is not occupied by the train. On DC layouts, the track polarity (which rail is positive vs. negative) determines the direction of train travel. If we changed the polarity of the loop power while the train is in the loop, the train would suddenly change direction. Therefor we must change the main track polarity while the train is on the loop track”.

Rich

ahh, so one side of each set of trucks is unpowered. I am a DCC guy, so I am no expert on DC rail power. But I wonder if the unpowered side of each truck contributes to the problem?

Rich

Yes, you are right and that is correct.

Both points A and B are gapped and while the loco is between A and B (on the loop), I change the polarity (direction) from forward to reverse, it still stops.

I would guess there is no immediate solution. I had been wanting to use my Tycos in my train operations. I will just have to let the yard loco break a train apart to put cars in my yard.

I don’t model a particular Railroad but I model eras for Railroads nationwide.

I have Southern, Pennsylvania, Penn Central, Conrail, CSX and Norfolk Southern as my east coast era trains and Union Pacific, Western Pacific, Burlington Northern, Santa Fe and BNSF as my western trains.

Most of my western trains are the Tycos. I have a UP and a BNSF that are not Tycos.

I will just have to operate (hopefully) keeping my Tycos off that piece of track.

I have learned that “a solution will eventually come”.

Thanks for all you guys help.

cplmckenzie

Yes, therein lies the entire problem.

As only side of each truck is powered, front positive - rear negative. When it enters the section of track or exits that section, the loco is stuck, half in - half out.