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I'm sure many people have already solved this but I'm in the process of building my first big layout and only. Bought a new MTH P&W Dash 8. Due to its length keeps stalling on my atlas turnouts. Most of them have power on track to at least two ends. I was told I should put power to all track/switch ends. This seems like overkill, any simpler solutions for a guy who is not a full train techie?

 

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Do you have any of these switches back to back or connected directly to other switches? Sometimes when you do that the 'dead spots' (no power) end up just right with certain engines so no pick up rollers are touching.

One thing to try is when the engine stops, note where the pick up rollers are and see if there is power to either one. Also check both pick up rollers to make sure they are both working and that a wire hasn't come loose somewhere on one of them.

The curved switches probably all cause a problem with an engine or two sooner or later just due to the way they have to be made because of the curve and the distance between the powered rails.

On my new dash 8 I have two rollers. Yes it seems that the curve 72/54 are causing the most trouble. but most of them do act up. when I try to run my dash. So far my NH ABA has not had the same problem. I'm powering the switches separate from track power. All told I have 23 switches on a 10 x 20 layout, two levels, using a math 4000 for track and a prewar train master for switches. I also seem to having up and down power issues, although I have 20 v going through the track. Guess I will figure it out one short step at a time.

I have a lot of experience with Atlas switches.  I suggest that you get a simple voltmeter and check that all of the third rail sections are powered throughout the switch.  You may have to run a jumper from a powered third rail section to the dead third rail section.  Atlas switches, especially the older ones, are notorious for not passing power to all the third rail sections.

Another problem that seems to plague these switches is dirty track - especially the third rail.  I have found that just cleaning the track on the switch will allow engines to pass over them.  The switch can be dirty even when the other track is clean and engines are running fine on the rest of the track.

Another problem may be that the wheels are contacting both the outside and middle rail at the same time. This happens on some engines and not others.  This causes a short which stops the engine without tripping the power supply circuit breaker.    The way to find this problem is to turn off the room lights and watch for a spark as the engine goes through the switch.  You can see this best when the engine has some speed.  Place a short piece of insulated tape on the rail where you see the spark to see if this solves the problem.  Several of my switches have pieces of insulating tape installed on the running or center rail.   

A third problem that happens with all switches is that some engine rollers are spaced so that both are on insulated parts of the switch.  Sometimes this can fixed by turning one or more of the engine rollers around or installing an extra roller on the engine.   

If all else fails, you may need to use a relay to power one of the running rails depending on which way the switch is thrown to fix this problem.  This is a last resort solution and requires connecting the relay to the switch machine.  Try the other solutions first.

NH Joe

New Haven Joe posted:

 

If all else fails, you may need to use a relay to power one of the running rails depending on which way the switch is thrown to fix this problem.  This is a last resort solution and requires connecting the relay to the switch machine.  Try the other solutions first.

NH Joe

I've attached the Atlas wiring diagram for the above solution.

Attachments

I too am experiencing Atlas switch problems and would appreciate some feedback.

I am using a O-45 switch in a crossover.  It is powered from a feed about 8 feet away.  I have tested electrical continuity through the switch with a home-made battery/light arrangement which tests out fine on any other part of the layout.  I have tested three locos through the switch: Lionel GP-7, Lionel HF15-44, Lionel Docksider.  I'm running all conventional.  All locos stop in exactly the same place right in the middle of the switch.  I have tested that the track is level.

Electrical continuity shows OK on my tester either side of the switch, but locos won't run on the far side of the switch from the power feed.

I've tried replacing the switch but get the same result.

I can obviously cure this by adding a second feed on the opposite side of the switch from the one that's there now but I want to solve the problem.

Any ideas please?

@leeg posted:

I was told I should put power to all track/switch ends.



It's a bit of work but in my experience that is the only way to avoid these problems.  As mentioned Atlas switches don't do a great job of routing the 3rd rail power and even if it works now it could lose continuity if you get a short/derailment etc. which burns up the (kind of thin) wiring.

Also cleaning the third rail helps a lot, specifically those portions of the third rail that aren't the standard blackened nickel silver.  The blackening agent used isn't very conductive.  I used a big pencil eraser to get it all off - works well.  You should have a copper / bronze like color when done.

Thanks everyone for your help I added a connection and it works fine.

i’m disappointed, though, in the product. Belatedly, I’m beginning to think Ross switches might have been the better bet. I have 17 of these Atlas switches, 4-5 being older and defective. (Typically one side of the switch works but the other doesn’t -really obvious ). The thought that shorting would cause those thin wires to break is disconcerting- having to rip up the track, ballast etc. after the fact is not a prospect I relish.

Perhaps i need to take preventive measures before I go much further.

Thanks again

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