Yesterday while running my trains, I noticed that I'm getting a very slight power drop on two of my modules. It's just happening on the one line but it's very odd. I've never noticed this before. When this train crosses from one module to another, there is a slight, yet noticeable power drop. This is happening in two of five modules. I've checked the connection and can't find anything amiss, yet it still happens. And here's the kicker, it only happens in one direction. I'm running a consist of 5 engines, 2 GP9's and 3 SD75's pulling 36 cars including caboose. I cleaned the track thoroughly and like I said, checked the connections but I can't seem to find the problem. I go down at track level and watched very closely as each engine crossed over these modules and I can't determine if any wheels on the engines are coming off the rails. This line is on a 12 foot 2% grade and the power drop only seems to happen on the down grade. It's really got me baffled.
Could you tell or remind us how you establish your electrical connections between modules? And is every track section connected to a feeder? Dom
Also, why do you say there is a "power drop?" Have you measured the electrical state at the point where you say there is a "drop?" Maybe, you see a performance change or unexpected performance but it might be explained by trak plan. For my N-scale, I have a long gradient that may be run either way and each way has a different trak configuration which affects performance. The trak plan explains somewhat different observed performance as the trains run along.
Hi Dom. I'm using a combination of three types of connections depending on my scenery and how the track falls. I'm using a standard piece of flex track with joiners at both ends to cover the span in some places, in the hard to reach places I'm using what I refer to as drop in pieces, which are MTL feeder tracks with aligator clamps on them. These clamps go between the tables and connect to feeder wires from the other two modules. These are held in place with foam nails and straight pins. This is just a temporary situation. Where I'm having the problem is on the flex track covering the gap. To answer the other question, I suppose power drop would be the wrong term to use. Let me clarify. When a train passes from one module to the other, the speed drops. I'd say probably by 1/4. Then when it crosses to the next module, it speeds up to normal again. It's like in real life, the train is going along at a reasonable speed and then the brakes are applied suddenly to slow it down. Does that make sense? All the connection appear tight unless there is something I can't see.
I should re-interate that the track that this is happening on is a double, 12 ft straight track with one 15 degree S bend about 2/3rds down. All on a 2% grade. Last night as an experiment, I tried each engine in the consist individually, and it is happening to all of them.
To stay with your problem a bit more, the unusual thing is that you've said that your train performs differently depending on the direction travelled. That led to my remark that it was something in the trak plan that affected performance. Can't imagine an electrical problem that could cause that. (But all I know is parallel wring.) You've also said that the problem occurs when trains cross a module border. Is the wiring for modules isolated? If so, look to the electrical junction of the module wiring with the main bus.
I'm getting this sudden slow down on the downgrade. It doesn't seem to be happening on the upgrade. Picture this. 5 modules end to end. Train proceeds on a 12 ft. 2% downgrade. Level on number 1, start grade on 2, crossing from 2 to 3 train slows by about 1/4 speed. train speeds up after travelling about 1 ft. train slows down again about 6 inches before crossing from 3 to 4. Train resumes normal speed until about 6 inches or so before crossing to module 5. Train now runs at normal speed. Number 5 is a loop that returns train back up the grade on compnion track to mudule 1 which is also a loop. Total distance covered one way, 18 ft 4 inches. I don't know how to explain it any better then that. Like I said, it's like the brakes being applied if it were a real train.
This problem may have been happening before now, I just have never noticed it before. What I don't understand is both tracks follow the same risers and this problem doesn't seem to happen when train is going up the grade. Only down. I'm perplexed. And now that I have been noticing it, it's really starting to bug me. I'm going to check the track and connections again today and perhaps I'll even check the gauge. Maybe the engine wheels are being squeezed a bit at these locations thus slowing them down.
OK, the next thing to consider then is the Consisting. Does any single loco do this? If the BEMF load compensation is on (defaulted on in many decoders), it may be fighting you, depending on several things. Run a single loco, with or without some train length behind it. If a train were long enough to go over the hill, as the end of the train transitions from the flat lands, onto the grade or finally to the top of the grade, both the load and slack on the train will change and thus the loading on the locos. One or more of the locos in the Consist may not either like it or just not run as well (friction, etc) when slowing down). .
Hi Jeff. Yes I have tried each engine alone and there is no change. I have not however tried each engine with a load. I must point out that I am not running DCC but rather block wiring and this only happens on the downgrade and the entire load covers approximately 6 ft in length. It is strange that I don't have this problem when the train is passing the same location on the upgrade and at this point the engines and about half the train are on the upgrade and the rest is flat. I will try running each engine individually with a load to see what happens. I'm also going to put two other engines that I'm not currently running on this track to see what happens with them. I expect it will be the same thing.
Ken, we may have to start calling your layout, "Mystery Layout" reminiscent of that radio orTV show years ago..........'Mystery Theater'
Hi, Your power loss as described, sounds like a slightly high electrical resistance in the feed to the track at some point. You have not mentioned that you have checked the actual electrical continuity resistance between the good and suspect modules but infer that you have only checked them visually. My suggestion would be to beg or borrow a good electrical meter and measure the electrical resistance between these modules. (with the power off!) In a good connection you should expect a low reading of less than 0.5 ohms. You may find a feed, connection or switch with around a continuity resistance of 5 ohms, such which could explain the drop in voltage. When a high resistance termination or joint develops it is often caused by the copper or whatever oxidizing, in which case it could possible acts as a crude diode affecting current in one direction more than the other, which may explain why it effects travel in one direction and not the other. I work at an electrical training college in the U.K. and very often come across switches even those rated for mains voltage that overtime develop a poor continuity issue. This is especially a problem when using the very low voltages that we use in Z scale. John
A voltage reading on the rails themselves, whether at opposing points on the rail or, with one probe fixed and the other probing before, then after the suspect section (then reversing the probe sequence process) will be FAR more accurate that a resistance reading in the <1 ohm range. Most all meters, whether $5 or $500 with only 2 leads will EASILY have 0.1, 2 or 3 ohm just in the leads, especially the cheapy ones. The only way around this is to have and analog meter with a Zero or a Digital with a Relative button. Press the two leads FIRMLY together, move the leads around a bit to assure the lowest reading, then Zero or Relative. Any cheap voltmeter can measure the track voltage difference. .
Hi John and Jeff. From what I've read of your responses, it sounds to me like I need an electrical engineering degree to really comphrend what both of you are suggesting. As a matter of fact, I do have a volt meter with all kinds of adjustments on it. Frankly speaking I don't have enough expertise in using it other then to put the leads on the track to see what voltage I'm getting in relation to the throttle on the power packs. I have to admit that I am woefully unskilled in this regard. Here's what I'm going to do. I'm going to tear up the track on both modules, and put some new stuff down. Perhaps that will eliminate the problem. I've been suspecting a problem with the track itself so I'm thinking that this will sort it out. I'll also be checking the risers for dips in the grades. There might be something very tiny that I'm not seeing that is causing the problem. Funny how I only have this problem on this line. It isn't happening on the other two lines and one of them has a long grade up and down as well. Most curious.
That's something else I've been kicking around, but once this phase of my layout is completed, there will be 10 or 11 modules and to power each of them separately will require one heck of a lot of wiring and each will have to be run to a block box and then to the power pack at a central location. I don't know if I want to increase the amount of wiring any more then I already have. It's complicated enough now.
All of my modules have the same connectors and so do the power supplies. I only need to un-plug the connectors to the module and remove the connecting tracks to completely isolate it. Then I can connect the power supplies to that module to test or troubleshoot it. We had a similar problem the first time we displayed our modules at a show. The speed of any train would drop by almost half everytime it got to a certain module. We removed the module so we could operate at the show until the module owner got there. We started checking the module and found that he hadn't completed his wiring. Some of the wiring that wasn't necessary for the show had been stripped and not connected. Instead, he had coiled the wire up and we were getting shorts from those wires. We cut off all the stripped ends to eliminate the shorts and the module ran fine. The owner connected all the loose wiring later and we haven't had a problem with that module since then. I hope this helps.
Newtoscale, why do you want to run each module back to a common power block? just make module-to-module interconnects (the main bus) using large wire (typically 18 gauge (1mm) wire and then on each module, short drops to the track using #22 or 24 (or even #26 if kept to <12"). This way, you can rearrange the modules at will. .
To add my two cents I'd say that after reading that entire post I'm still wondering how newtoscale (sorry my friend, I don't know your firt name:tb-wink did the wiring on his trackwork. I mean, did you solder feeders to every track section? Myself I'm not fond of electrics, my knowledge and understanding of electrics are scarce (that's why I don't want to mess up with DCC neither) but I built a first module (that I led to abandonment), then I started a modular layout, indeed a yard in the beginning (that I put into "sleeping condition" as my goal regarding this future layout is in omplete change), and finally I'm (slowly) working on a small layout for my hometown appartment. All these have one common feature: I soldered feeders to every track section (Marklin sectional + Peco flex for the first and MTL flextrack for the two second ones). Then I linked them to what I could call a "bus" using dominos. I like this option, it's easier to work with than soldering and if something goes wrong you only have to unscrew. But as a result, I've not the least problem of power drop, the juice flows constantly everywhere and my trains run flawlessly both ways. I proceded this way only because I remember the HO layout I had when I was a teenager, consisting of sectional track only set together, with no more wiring than the connecting track (such as Micro-Trains # 990 40 905 Electrical Clip and Wire, to keep related with Z scale), and it was a nightmare to operate: stalls, power falls, etc... That was that I wanted to avoid on my Z scale layouts. Hope this helps, Dom
I don't really want to do this. As I said, it would be far too complicated and I expect, time consuming when assembling. I want to stay as I have things now for simplicity. The way my layout will and is being built according to the theme I'm modelling, none of the modules will be interchangable. They will have a specific order when connecting together. If I want to connect to someone else's layout or module, there will have to be a transition modules of somekind at the far end of my layout, but I'm a long, long way from that.
