I'm about stumped by track dead spots on my N scale DCC layout. I am using an NCE Pro Cab with power drops about every 24". When running a loco on the layout it will seem to lose contact and come to a stop. If I move it gently forward even an inch it will run. I'm experiencing several of these spots around the layout.
With a Multi Meter set on 20 V ac I have checked the track about every six inches and get a uniform 13.8 volts all the way on all branches of track.
I'm running a Model Power 2-6-0 Mogul. I did set up a separate test track of about 48" and it seems to run well.
Can anyone shed some light on what is causing these dead spots and what to look for?
Thanks in advance for any help !
RGSBob
Dirty track or locomotive wheels? Loose connections on the locomotion? Loose track connectors that move slightly and loose electrical continuity?
Somethng to remember, measuring the voltage without a load does not tell you what happens when you put a load (run a train) on the system. If the spots where you lose power are consistent, I would add feeders closer to those points.
I agree with dry heat. Tell us more about your buss, feeders, soldered rail joiners, barrier strips or suitcase connectors
Henry
COB Potomac & Northern
Shenandoah Valley
SouthPenn Dirty track or locomotive wheels? Loose connections on the locomotion? Loose track connectors that move slightly and loose electrical continuity?
Mike
It seems to me that all of the above replies are spot on. It could be most anything, dirty track, gunk on the loco wheels, insufficient feeders, loose rail joiners, whatever. Need more info.
Rich
Alton Junction
Are there any items like rerailers or grade crossings etc. in these spots that could lift the wheels of the rails just enough to lose electrical contact?
Funny, that I had this discusssion with my mentor earlier. There are many, many factors to consider about dead spots. Similar causes arise for derailments. I have one car that won't navigate a turn, but most cars are fine. Is it the car? The track? Both? Moon alignment? The airspeed velocity of an unladden sparrow? Etc?
RGSBobCan anyone shed some light on what is causing these dead spots and what to look for?
Bob: If this happens with different locos I would suggest:
1) dirty spots on track.
2) dips in the track, causing wheel to not touch, not pickup current.
3) the aformentioned rerailer, etc causing a wheel to lift at this spot.
It would seem to me that moving the engine an inch to resume motion indicates a very local problem.
I am modeling HO, and have experienced similar issues. I have found that in 99% of all cases, the engines are the culprit and not the track. Thoroughly cleaning the pickup wheels of the engines have always solved the issue.
And it may not be just the wheels on the engine. There are other points of mechanical contact between the wheels and the motor. Dirty wipers on the wheels, dirty bearings that transmit power to the chassis, etc..
Sometimes you have to look a little deeper that what you can see.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Whether this 2-6-0 picks up current with drivers on one side only, I know from the MR review that it has traction tires on the third axle drivers, so those drivers probably can pick up with flanges only, leaving the treads on only 2 drivers on each side picking up current. All it takes is a tiny low or high spot in the rail and you could have one or no drivers on one or both sides actually in contact with the rail.
A way to cheat having to make a 'megger' out of a multimeter is to rig up a wheelset on a stick or handle that carries good pickups, as large a motor as you run, and some adjustable load like a friction brake for that motor. If you want, put some variable weight arrangement on it. Then rig your voltmeter across this for the drop.
You will very quickly find any issues with track power, in differential diagnosis from locomotive issues. If you can't reach part of the track work, put it on a car (with the contact wheels 'floating' with weight or spring tension for assured contact) and push it where needed...
swisstrainI am modeling HO, and have experienced similar issues. I have found that in 99% of all cases, the engines are the culprit and not the track. Thoroughly cleaning the pickup wheels of the engines have always solved the issue.
thanks
greg - Philadelphia & Reading / Reading
Being N scale you are a little stymied to see the real cause if it is the dip in the rail, dirty wheel or track scenario.
I'm in HO like a number of friends and even in that scale, the lighter weight of some locos and the very slight undulations of the track are enough to cause the wheels to lose contact. This most often happens on curves.
All of my curves are superelevated about .025" - any more on a small layout might look like a slot car embankment - and I find I have needed to shim under straight areas where there are drops.
I use recycled plastic lids at about .005" as the packing material but any scrap material will do. However you may have trouble seeing the area in N scale. I have enough trouble in HO!
Might I suggest that you get a couple of freight cars together with Kadees and wearing a magnavisor or holding a magnifying glass, look at the movement of the couplers as you move them slowly over the trouble spot.
Unlike the prototype, models are not as forgiving of flaws in the track and you may be able to detect a drop in the track that may not be apparent under the naked eye looking at the wheel contact of a 2-6-0. It only takes a couple of thou gap to cause a break,
Goodl Luck
Cheers from Australia
Trevor
forester6291European or African. forester, isn't it "African or European"? (And don't say you don't know, or off the bridge you go!)
forester, isn't it "African or European"?
(And don't say you don't know, or off the bridge you go!)