I have a one month old Atlas B40-8w with an NCE decoder in it. I bought both the engine and decoder new. This engine runs around, hesitates, stalls, slows down to almost a stop and picks up speed even when at full throttle. The wheels are clean, so clean I can't get hardly any dirt off of them. I have a Kato SD70MAC with a Digitrax decoder that runs around the layout without any stalls or slowdowns, at any speed, so to me, this would rule out any track problems. I have to run the Atlas around at almost full throttle to let it have enough momentum to keep going in the areas that it wants to stall, and although it will stall in certain areas of the layout every time, it will also stall in areas that it ran around fine the last time it went around? So what do I do?
How much runtime does it have? Might be a problem with the motor contacts where they go into the decoder. Or the contacts in the side frames are dirty.
It's got a fair amount of time on it. The motor contacts aren't an issue. With an NCE decoder, the decoder is slotted, and the motor contacts fit into these slots. I had this problem before, and I actually did get it fixed for the most part with a bunch of track cleaning. I relaid some track due to some scenery problems, and now the problem is back, only worse than before. I can't figure out why my Kato would glide over all of these problems at a crawl, and this Atlas won't run worth a *#(&! I thought about a new decoder, but it seems like the engine has horrible electrical pickup, so a new decoder won't help. Both brass contacts are touching the pickups on the trucks. How do I check the contacts in the frame? You mean the brass strips that get power from the rails, right? I think that thi will be my last Atlas engine. This is my second one, and I've had bad luck with both of them.
First clean your wheels until you can't get any dirt off them. Second clean your track. Becasue a heavier 12 wheel loco runs ok does not mean you don't have a track problem. Your lighter 8 wheel loco will be more sensitive to dirty track. You said it tends to slow in the same areas so that would more than likely point to a track issue.
Ryan, I am talking about the ones inside the trucks, the ones that the axle points go into. These may need cleaning,or the axles are gauged too narrow.
Hello, I may be way out in left field, but have you tried doing a full reset on the decoder? Many strange problems can be cured with a reset. I always reset my decoders after I install them as part of the programming process. Just a thought. Mark
Ryan: I agree with Mark. Try resetting the decoder to it's factory default values and then program the decoder again with the loco number. This procedure often solves these irritating problems that have no apparent cure. Stay cool and run steam.....
I think you have a electrical problem and not in the decoder. As said clean the cups that the axel points sets in. Also clean the pads that the decoder picks up the power from the frame from. if these point don’t fit snug this could be the problem. Just adj the frame or shim the decoder so the frame fits with out any slop.
I'd have to say this points to the engine. There is either an intermittent poor connection internally, or perhaps that decoder is problematic. Boxcab E50
Ryan: I don't use NCE decoders but I would check CV 8. That's the CV that will reset a Lenz or Digitrax decoder to factory default settings. The value for CV 8 is in the NCE instruction flyer for the decoder. Place the loco on your programing track and Program CV 8? to whatever value is in the manual. First make sure CV 8 is the setting for returning the decoder to the factory default values for the NCE decoders. If you correctly re-programmed the loco to the default values, then it should run on address 03. Then run the loco on your layout using address 03 and see how it runs. Then re-program the loco address(number) into the decoder on the programming track. Stay cool and run steam.....
Hello again, I went to NCE's WEB site, and downloaded the Owner's manual for the N12AO decoder and found the following for you: "CV30 Set this CV to 2 on the programming track and the decoder will reset to factory settings." I hope that this will help you to determine your problem, I have several dozen Atlas (and Kato) locomotives, over 60 or which have decoders in them. Although some Atlas locomotives have initially have problems after installing DCC in them, after initial troubleshooting, they are some of my best runners. The Kato engines tend to run more quietly than the Atlas ones, but the Atlas ones seem to run cooler than the Kato ones. All my engines that are DCC have the "Plug and Play" type installation. I haven' t successfully done a DCC installation in a non DCC ready engine yet (I've only tried once). What the other people have said about contact at the axle points is correct, but since you said the engine is only 1 month old, I wouldn't expect that to be a problem, unless you have set your track up on the floor (or on a rug especially) Mark
I reset the decoder back to its default settings. No difference, so I guess when I get some time I'll take the trucks apart and see what's in there. The board is shimmed, so I know its making good contact all the way around.
Hello Ryan, I'm not sure what you mean by "shimmed". Shimmed with what kind of material? On a few of my Atlas units, I have insulated the frame next to where the motor strips are with Kapton tape, but other than that, I'm not sure what you are doing. Mark
The decoder is shimmed with a very small piece of cork at both ends of the frame to make sure that the corner points make contact with the frame. It is in the correct position, and seems to be properly seated. I'm going to work on this tonight, so I should have some results pretty soon. I'll let you guys know.
I cleaned the pickups on the outside of the wheelsets. They were dirty. No change. I cleaned a test section of track with a bright boy and rubbing alcohol. No change. I installed the DC board. No change. Performance is still the same as when I started. I have some measurments for you guys, tell me if they're wrong. N scale track width .346 Atlas Dash 8 wheelset width .330 Atlas SD60 .331 Kato SD70 .341 What is the proper width supposed to be? This is from outside of flange to outside of flange? The Kato wheelsets are a lot wider than the Atlas wheelsets. Are the wheelsets too narrow?
Back of flange to back of flange minimum should be .297 Center of flange to center of flange should be ~ .323 http://www.nmra.org/standards/S-4_2ScaleWheels.html Easiest way to measure is with either the NMRA standards gauge or the Micro Trains Micrometer Coupler height gauge also has wheel gauge check slots. Lots of possible causes, but many issues you have mentioned point to track problems, such as "always stalls at a certain spot" and "Problem reappeared after relaying track", neither of which could be caused by a decoder issue. Wheel gauge can cause possible contact issues, but these are not that common and will not change over time (unless you have changed the wheel gauge ). Fastest way to make certain what is really at issue would be to take your loco and run it on another layout. Do you have access to a multimeter? Diagnosis will be much easier if you can take some voltage, resistance and amperage readings.
