I have two Proto 2000 F7s (GN Empire Builders from last year or so). I hadn't run them much until recently but both of them have intermittent stalls at almost all turnouts in the yard and on the mainline. This goes away if run at slightly higher speeds. (approx. 5-15 scale mph as opposed to approx. 30 scale mph). (Or "20" on the DT 400 throttle as opposed to "5 to 7" in the yards).
My good friend who opened the up and looked them over performed the following diagnostics:removing the shells and looking for any visible signs of loose electrical connections. None were observed. I even gently tugged on a few wires but none let loose. I seem to recall taking a couple of trucks (but not all) apart with no visible excess or drying grease or other lubricant observed. I think I checked wheel gauge, coupler trip pin clearances, coupler height and cleaned wheels.
Once, prior to that, we saw that the front truck wheels on one F7 didn't appear to be turning but upon inspection/testing they did and they are now. What's up with THAT? When the locos stall briefly at turnouts they almost always come back to life and proceed as if a keep alive capacitor was involved but I don't thin the Tsunamis had them.
Appreciate ideas and or experiences with your Walther Proto 2000 F7s if similar and how you solved the problem.
I thought about posting this in electronics and dcc, but not sure what the issue is...
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
The question is did they ever run continuously on these locations? If they did, then the track & wheels are likely dirty.
If they did not, then your min voltage setting on the decoder is too low.
In either case, the integrated PMW voltage to the D.C. Motor is too low to sustain motion, thus it stalls. As you increase the power setting, the units do not stall. Higher power setting is a higher integrated voltage to the motor.
People recommend lightly rubbing a 4b granite stick on the rails. This helps retarded the DCC dirt build up.
Since it is happening on turnouts, the gauge or electrical connection may be the source. Short wheel base engines and long, high number turnouts are more sensitive to this problem. Your description does indicate that this is the problem, but it may be.
So many trains, so little time,
Larry
www.llxlocomotives.com
Do you have live frogs or insulated ones and what number turnout?
There are a couple things I can think of that might be wrong with the engine itself.
Assuming you did a good cleaning of the wheels...
1. Commutators can oxidize over time. Cleaning them helps. On can motors though this is easier said that done. So your best option is to run it at high speed for 30 or so minutes and see if the brushes can clean it with friction.
2. Cheap China paste caps have a tendency to depolarize after not being used. This means they nolonger hold the backup power like they used to and it is these very same caps that keep your train going over short sections of bad pickup. There is a way to reform them but it doesn't always work. Replacing the cap might be a good option.
3. This might be true of the proto 2k but I'm not 100% sure. The phosphur bronze pickup mechanisms can be become dirty and conduct poorly if there is oil on them. (Particularly in journal pickups). I have a scope and LED test rig that allows me to test mine. But since 99% of people don't have this equipment you might just have to disassemble the truck and go at it with a q tip and 70% ISO alcohol. For back wheel brushes I lightly sand them with 40um grit paper till nice and shiny.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Don,
I'm the Captain's friend who has been trying to figure out what makes these locos stutter. In the last sentence of your reply you mention "back wheel brushes." I'm probably going to feel real dumb when you answer my question, but what are "back wheel brushes?"
skagitrailbirdI'm probably going to feel real dumb when you answer my question, but what are "back wheel brushes?"
Keep alive is one solution.
Rio Grande. The Action Road - Focus 1977-1983
First off, I think cleaning the track and the wheels is a good first start, and certainly isn't going to hurt.
Since the problem happens on turnouts, you probably have dead spots. You can't do anything about plastic-frog turnouts like Atlas snap-switches, but metal frogs can and should be powered. There are also techniques to power point rails which usually rely on somewhat shady physical linkages for power.
Have you tried buzzing out the connections between the wheels? All 4 wheels on each side should be connected, and that should not change as you turn the trucks. A physical inspection of the wires is nice, but electrical contact is what really counts.
It takes an iron man to play with a toy iron horse.
MisterBeasleyThere are also techniques to power point rails which usually rely on somewhat shady physical linkages for power.
"Have you tried buzzing out the connections between the wheels? All 4 wheels on each side should be connected, and that should not change as you turn the trucks. A physical inspection of the wires is nice, but electrical contact is what really counts."
No, we haven't. But that is a good suggestion and we will do so. I also like the idea of running them at speed for a while to see if things loosen up. I will put them on rollers for that.
The turnouts have metal frogs but they are not powered. I know conventional wisdom is to power them but I ran this type of diesel on my layout for several years with #4,5 & 6 Wakthers-Shinohara DCC friendly (un powered) metal frog turnouts with absolutely no problems.
And while I think we have cleaned things well, it won't hurt to go over them again.
Thanks guys. I have run the engines in forward and reverse for more than an hour several times in case the grease had solidified somewhere, etc. No improvement.
The turnouts are all Shinohara/Walthers, DCC freindly and the yard consists of #5s. The main has #6s. These are the only locos that exhibit this behavior. I have four wheeled switchrs of various manufacure (including proto) that have shorter wheelbases and no issues.
Live frogs have not been necessary with any of the other engines including steam engines. I am pretty sure it's only these engines...
I tried adjusting the start up voltage and starting speeds but haven't seen improvement. Do I need to be in consist mode or something other than "plain" CV enties for that specific engine, with a DT400 (digitrax)? I currently am using the DT500/duplex manual if someone can point me in the right direction/pages.
This layout has been fully operational for several years so this sure SEEMS to be a loco specific issue.
Thanks. I'll keep reading and trying...
Does direction matter? Are they doing the stalling running alone, without a train? Running individually? It definitely seems to be loco related. The question is it one or both?
In consist, a stalled loco will stall the consist.