One Loco out of 6 stops on same spot ???


Gdelmoro

Member
Hi all, I posted this on another site also hoping to get some ideas. I have 6 DCC locomotives. 3 Steam and 3 Diesel. Only 1 stops at this same spot on a very slight mainline curve.
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Right about where the mark is. That curve is really about a 38* radius. There is a gap just prior to that spot but both sides have feeders.

The two 282's, two SW1500's and the SD7 blow right through. The 462 Pacific stops then sometimes will start up again on it's own after about 3 seconds.

Any ideas?
 
As it's near or at an insulated gap, I would say you could have a peak (high spot) at the joint. I identified one just like that on the club's layout last weekend, that does the same thing. Doesn't take much to lose contact on some locos.
 
What are the brands of the locos?
Broadway Limited needs to have precise DCC power and signal to operate. Anything that is skewed in the slightest, or slight changes between powered sections will cause the loco to stall, reboot then start rolling again.
MTH, Athearn Genesis and Intermountain are more tolerant to sloppy DCC conditions.
 
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Odd things happen without explanation. When I purchased the Broadway I-5, it derailed and flew off the table in the same spot twice. Nothing else has ever done that. Luckily, it landed in a milk crate with stuff in it, so the damage was minor. I ended up putting guardrails up to fix it. The I-5 has never attempted to jump the tracks there again. Odd.....
 
i've wondered how locomotives with multiple contact points can fail to get power. By multiple contact points, I mean multiple wheels, metal on metal contact between tender trucks and metal frame, and a metal draw-bar. Of course there's a problem if the drawbar looses contact, but I also tried a wired connection. (I added additional pickups to the engine and have also added keep alives).

i'd suggest you use a meter to try to identify on which track there is no contact and then try to identify if all wheels have lost contact with the track.

Another thing I've tried is using a clip lead connected to a track and making contact with a wheel to help identify if it's the contact between the wheel and track or possibly the wheel and frame/pick-up.

while the tops of the track may be clean, don't wheels really make contact with just the inside corner? is it clean?

i'm really curious to hear how you make out. how can multiple contacts fail?
 
The DCC data is transmitted in packets just like any other form of addressed data. Without a forward error correction feature in the system, intermittent contact along with arcing can interupt those packets to make a corrupted file or distorted file. Distorted files make your loco do strange things until you tip it off the track for a moment.
 
Thanks for all the posts. The loco is a BLI Paragon 2 0-6-0. I'm in the process of replacing the track in that area so that there will no longer be a gap. It was left over from when the layout was DC. The Loco itself checks out, wheels on loco and tender all in gauge and clean. All my other BLI locos ran right through.
 
I would have to agree with you Ken. A bit more head and a bit less solder.
 
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