Hello, I’m brand new to this forum. Please help! I just completed my first layout using Atlas O track. Its about 9X12, L-shaped, with two main lines and some sidings. I wired it for 2 cabs and twelve blocks. I used 16 ga. wire throughout, except 18 ga. track feeders, place about every 3-4 track sections. Plenty, I figured. I run MTH engines with PS2. So here’s my problem. When running in speed control mode (default setting) the engines will SOMETIMES accelerate after running through a switch (O-36 and O-45) before quickly returning to normal speed. This happens very eradically around the layout; all the switches have done this at some time or another. The problem occurs at least once each lap around the layout. It doesn’t matter if one side of the switch is insulated or not. I’m pretty sure I have good connections all around and enough feeders. So what is going on? Any suggestions will be greatly appreciated. Trainhead
Hi Trainhead,
First I would like to welcome you to the CTT forum.
Let me ask you a few questions on your layout and type of MTH engines that you are running.
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Are you running Steam or Diesels [?] If you are running Steam, it may be a bad tender wire harness or bad connection at the engine. You may also have dirt (even extra smoke fluid) on the motor fly wheel. If it is Diesel, less chance of this being a problem. The change in speed may be a bad speed control sensor.
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Are you running conventional or DCS [?]
tom
Spankybird,
Thanks for your response. I own four MTH steam locomotives, all with PS2, and run in conventional mode. The problem occurs no matter which of the four engines I run. This leads me to believe the problem is either in the feeder wiring (I think I have plenty) or is something inherent in way the switch is wired by Atlas. The engines seem to surge through the switch before quickly settling down to the set speed. I’ll check for dirt/oil on the flywheels but any other thoughts you have would be appreciated.
Trainhead
Hi Trainhead,
I don’t think this is your problem, but it is worth looking at. Check your batteries in the engines to see if they are fully charged. Sometimes PS2 has small problems until they are fully charged.
I am not familiar with Atlas switches. Do they run off track power or fix power. If it is fix power, what voltage are you using. Is the switch providing power to the center rail at that voltage? Just a thought.
Try checking your track voltage with a volt meter before and after the switch and on the switch. Is there a different voltage anywhere?
Sorry I can’t help more
tom
I just got a few of the “ATLAS” switches myself(2 rail)
Don’t know what the total problem is,but I would go for #12-#14 wire.
Have yet to install them,as everything else is handlaid.
Hello Spankybird,
You raise an interesting question regarding switch power. Atlas switches are powered from a fixed source, not track power. But I would assume that the fixed source only runs the switch machine, not the center rail. I could be wrong though. I power all twelve switches on the layout with a small 30 watt Lionel transformer dedicated to this use only. I will take your suggestion and check voltage before, through and following the switch. Thanks again, you’ve given me a place to start troubleshooting before I rip out all the blocks, go with 12 ga. wire and upgrade to DCS!
Trainhead
When you go to DCS, install it first and try it. Your present wiring may be just fine. I have pushed the limits on some of mine, and it works just fine.
Like I say, try it first and see how it works.
tom
Hello Tom,
Honestly, I’m not sure I’m ready to make the move up to DCS just yet since I’ve only had the layout up and running for the last month or so. However, when I do move up to DCS (it really has some neat features) I will definetely try it with the existing wiring first. I’ve given more thought to and checked out the way the switches are powered. Just the switch machines are externally powered. The track power comes through feeders via the center rail. I was just messing with the layout earlier and can’t find any voltage drops or spikes, at least with the voltmeter I’m using, so I’m still at a loss as to whats going on. Thanks again for all your advice. I may try the Atlas O forum when they have it back up and running, sometime in the fall.
Trainhead
Trainhead,
First, I would definitly go with DCS if you have the bucks. Though I am still learning all the ropes I like the features. My only disapointment is I think the directions and explainations could be better.
Second, I am running only MTH engines on AtasO track and switches. You are correct that the fixed power only runs the switch. In command mode at cruising speed the engines go though the switch just fine. (I have eight) Try cleaning the center rail, and your pick ups. As soon as I get a chance, I will try running conventional mode. Good Luck!
Hi Rickm120,
Thanks for jumping in here. Gee, it took a long time for you to do your first posting.
Welcome to the forum
I would like to know the results of your testing of the PS2 engines on these turnout.
A PS2 engine has speed control on (unless it is turned off) in both conventional and command mode. The only reason for a change in speed in conventional mode is a change of voltage, or as you suggest, dirty roller or track (which is basically a change of voltage) or a broken connection between the sensor and the board. This could be a bad wire harness or bad solder on the board that the harness plugs into. Also the sensor may also be bad. I have one engine that does come out of speed control when the battery is low. Once running the engine for a while and charging the battery, it runs fine.
Do to the fact that Trainhead has four engines doing this, and it only happens at the switch, and he has a speed increase not a drop in speed (dirty track – rollers), I believe it might be do to the switches.
Please let us know the results of your test.
Thanks
tom
Hello Rickm120 and Spankybird,
I tend to agree with Tom that the probleme likely lies in the switch itself based on the fact that all four of my engines have exhibited this problem (acceleration or surging through the switch) at some time or another. It seems unlikely that they all have loose connections or sensors. What is really bizarre is that the problem doesn’t occur with any regularity i.e. at the same switch on every trip around the layout. After some checking I find that I have established blocks at every switch. Although I don’t think they’re dirty, I’ll clean the pickup rollers. I originally thought the problem was due to differences in the track voltage as the train travels into a different block but because the engine quickly resumes the set speed I’m not sure my wiring is the culprit.
Rickm120, I too am very interested in the results of your tests in conventional mode. I will try running my engines with speed control turned off and see if the problem continues and report back here.
Thank you both for your input,
Trainhead
Hello Trainhead & Spankybird,
It did take a long time to post as I don’t do much forum surfing. I was actually checking the forum for some other info when I came across this topic, and thought I would add my penny’s worth. Just as an FYI, I have added a new leg on my layout and am waiting for a new turnout and some track to be delivered. As soon as I get it (hopefully by Friday), I will clear the table and run some trains over the weekend. If I cannot get the same problem to happen, I will disconnect the DCS and try a run on straight track power and the MTH remote that came with one of my sets. BTW I am presently running diesels with PS2.
I think that the block junctions at the switches are something to think about. Whatever voltage drop you have through your feeders and track pins is reduced when the two feeders to adjacent blocks are connected in parallel, as they would be when the pickup rollers straddle the block junction. AWG16 has a resistance of about 1 ohm/250 ft; so I doubt that the wire size is the problem. Are the connections between track sections tight between the feeders and the end of the blocks?
By the way, you might reconsider the wire size from a safety viewpoint. AWG16 is good for only about 10 amperes. If your transformer can supply more than that to a derailment, you might want to use heavier wire. Wire that is heavy enough to be safe is usually a considerable overkill as far as voltage drop is concerned.
Hello Lionelsoni,
Thanks for jumping in. With my relatively small 9X12 layout the wire runs are pretty short. I thought 16 awg tied into 18 awg feeders would be fine. I use two Z-1000 transformers (100 watts ea.) with Z-controllers to power the two cabs. Do you think these requires larger wire?
I keep leaning towards a voltage drop or spike across the swicth/block as the cause of my problem, but the engines accelerate or surge as the engine passes through and just beyond the switch, they don’t slow or stall. I think the connections between track sections are OK because the trains run smoothly everywhere else around the layout, and keep in mind the problem doesn’t happen with any regularinty at the same switch with each trip around the layout. I’ve yet to run my four MTH steam engines with the speed control turned off, but hopefully will do so this evening.
Trainhead
The inconsistency that you described is one thing that made me think of imperfect track connections, which might change with each train passage. If you could attach two small wires to the rails on each side of the gap at a switch where you have observed the problem, you could look at the voltage difference between the blocks with a voltmeter. You should not see any significant voltage difference as the train approaches and departs, of course.
I’m not familiar with modern transformer ratings, so I can only repeat that the wire should be heavy enough to handle the greatest fault current. Approximate wire ampacities are 8 amperes for AWG18, 10 for AWG16, 15 for AWG14, 20 for AWG12, 30 for AWG10.
I don’t use feeders myself. I have had good results by soldering the rails together, and by minimizing joints by using 3-foot tangents as much as possible, on an 11x18 layout.
Hello Trainhead,
After logging off last night I made some teporary track modifications and ran one of my diesels in conventional mode and with the the speed contro off. It ran fine for the first few trips then I had the opposite probem; My train actually hesitated through the switch and the horn blew. But I know that is a dirt probem as I am doing alot of work on my layout and there is alot of dust. But, I had to test the theory. Unfortunately my PS1 Hudson steamer is in the train hospital with a broken draw bar. I contacted MTH and the part is $3.00 and shipping is $6.95. I am going to try to get it locally. As soon as I do, I will test my PS1. I will clean everything over the weekend and continue the test.
Trainhead,
Several of the forum members have spotted the basic problem for you. The loco is losing power (or seeing reduced voltage) as it crosses the Atlas switch. The test by Rickm120 is a good one (conventional mode with speed control off) as your loco will stall over the switch versus speeding up.
As suggested, clean your track (particularly the center rails) before, after, and on the switch really well as a first step and prior to the other suggestions I make below. As with all things, we could offer you tons of good advice and the problem you actually have is completely different.
From my extensive experience with Atlas switches on our large club layout, we have experienced several repeatable problems with crossing these switches and I offer some potential advice below. If you try our ideas below, make sure you do it on one switch at a time to make sure you have a reliable fix for the problem you encountered as some of the solutions will alter the appearance of the switch. I would have posted photos but the very expensive digital camera is in the shop for the 4th time in 18 months.
- If cleaning the track is unsuccessful, make sure you have a good connection with the rail joint connectors from the tracks leading to the switch. I have had a lot of trouble with these rail joiner connectors not making good contact, particularly over time. On our club layout we have had to solder nearly all the connectors or run a jumper wire to each rail section as these press fit connectors (similar to HO rail joiners) do not maintain a positive connection with time due to oxidation and temperature change effects. This is not new, the N, HO, etc., folks have the same problem with rail joiners and all modelers with permanent layouts usually have to solder track feeder connections at some point.
Additionally, this voltage drop may be caused by a couple of issues with the design and construction of the Atlas switch.
- The center rail between the poi
I am surprised to hear that a speed control would be designed to speed up the train when the voltage drops. What would be the point of that? And why would one want to use such a system any more than the old scheme where the train slows down when the voltage drops?
I built a new layout 12X 20 layout using Atlas. I currently run only Lionel, so I can only speak for Lionel engines. On my past layout , I used Lionel track, and 072 switches.
I have now experienced your problem with both types of track, so this is not only unique to MTH. I addressed this problem with Lionel, and it was explained that this was caused by the Cruise Control feature. Unfortunately, the problem is with an older engine which I cannot turn off the cruise. I remedied the lurching by installing a jumper wire from the tender center rail pickup to the engine. So much for wireless teather. This did help the problem though. On some of my longer engines, I do not have the same problem, except on the Atlas curved switch.
I have not had a problem on my atlas switches, except for a few engines that have paicup rollers that are close to each other. One other club member had stalling problems on his atlas switches, and connected the outside rails with a jumper wire at the switch to correct it.
Fred