Stalled Locomotive on Atlas 90 degree crossing

Model Railroader Electronics and DCC
1

Hello,

I have a BLI Heavy Mikado (2-6-2) that I recently purchased that has been shorting (it turns itself back on) when crossing an Atlas 90 degree crossover at very slow speeds. Basically when the last 4 tender wheels land on plastic parts of the crossover the locomotive shorts out, then kinda sputters and turns on again and proceeds on.

I’ve checked with a multimeter that there definatly is power to all parts of the rail.

The first 4 tender wheels are on powered track as well as the last 4 of the driver wheels. I thought that maybe because the 1st four driver wheels were on another crossing that this combination was causing the short, so I purchased another 90 degree crossing and ran the locomotive very slowly through it and the same short happened.

I do have 2 other steam locomotives from Bachmann (both 2-6-0) that run perfectly fine thru the crossing.

I’m really puzzled why the BLI is having such an issue. I’ve attached a picture for more clarification.

https://farm1.staticflickr.com/806/40973083781_044a3c587c_m.jpg

2

Welcome [#welcome] to the forums!

First off, the BLI Mike will have sound, is the Bachmann the same?

I ask as I really don’t think that the BLI is shorting out (a short happens when the two opposing polarities are crossed with eachother, thereby cancelling out the positive versus negative power flow, effectively killing all power, especially if it is tripping the breaker.) so much as, as your title implies, stalling, or, more accurately, losing power for a very short time, and the sound and motor control resets itself.

This is why I ask if the Bachmann is also sound equipped, as sound locomotives are more finicky when it comes to a power interruption than non-sound locomotives.

Or, again, to be more accurate, you notice it easier on sound equipped locomotives as the sound will shut off and reset itself, where on a non-sound locomotive, it is still losing power for that split second, but you are less likely to notice as there is no sound to cut out.

What this really appears to be, is that both of the units (if the Bachmann is non-sound) are momentarily losing power, and coasting just far enough that they regain power, and keep going. Atlas crossings have insulated frogs, so a actual short is much harder to do on them, but a momentary power loss is very common with insulated frogs.

Again, [#welcome] to the forums!

3

Hi

Just a wild guess, but have you checked the wheel gauge on on all axels?

Allso could the wheel tread be bridging the gap in track going in the other direction?

Cheers

Lee

4

First off thank you for the replies and the welcome.

I’m very new to train modeling so it’s definately been a learning experience.

The Bachmann locomotives are both DCC (Alco’s 2-6-0) with full sound.

When I lift the 8 drivers of the BLI off the track it continues to run, and also when I lift the tender off the track the locomotive drivers will continue to run. This is what confuses me because when it does stall on the crossing, at least 2 sets of drivers and a 4 tender wheels are still on the track (the non crossing portion). When it does stall at the exact same place at slow speeds, I took a multimeter to every spot the locomotive was on the track and was getting around 16.8-17. It seems the BLI locomotive which is alot larger than the Bachmann needs more power or something.

If its worth anything, I currently only use the Bachmann E-Z controller. The smaller loco’s start up alot faster. Would it make any difference at all if I upgraded to like a Digitrax or something?

5

[sigh]

I wonder if he solved the problem?

Lee

6

Well, with only one post to his credit, it may take a while to find out since he is still under moderation.

Rich

7

In testing my layout years ago, I found that some locos tended to short/restart going thru certain turnouts. It wasn’t easy (I needed forum help), but it turned out the turnouts were older generation Atlas, and the wheels of some locos “reached across the rails at the point portion”. I got rid of the few older generation turnouts, and had no problem with replacements.

One other comment… on the Atlas #8s, I had to put in Atlas relays to provide continuity. This could be the situation with a crossing, but that is a guess.

8

I don’t have any crossing but here is what one looks like up close, a code 83

It looks like the vertical rails have an exposed area in the flangeway as they cross the horizontal rails. Could a wheel flange be hitting one of those areas?

I would think a steam engine could cross those little plastic bits without losing power. Not sure that my 45 tonner could.

9

  1. Please clarity the interruption. Sometimes one can be so brief (if a sound loco) that the speed does not appear to change during a sound hiccup. I think you are describing something of longer duration, so if proceeding quite slowly, does the loco stop and stay stopped? And only go through the interruption if faster than a certain speed? If it stops at slower speeds, does your system indicate a short?

  2. Do check with NMRA gauge that the flangeway depth is adequate and not raising the tender wheels. And check that the tender wheel flanges are not too large. I have three code 83, 90 degree Atlas in series (circa 2011 or so) that seemed to contribute to problems so I filed the plastic a bit deeper.

  3. Are you sure your tender truck wheels pickups are working on both trucks? And both sides of the loco as well? I have a BLI 2-8-2 mikado that I need to check, on the To-Do list. When I run it over a strip of alcohol wet paper towel, to clean the wheels, the power pickup interrupts when one of the tender trucks crosses the towel. That may be indicating that the truck on the track at the time is NOT picking up. You may want to do this test, to assess all pickups are getting to the decoder.

10

I could see a loco with deep flanges going left to right there hitting the exposed bit of rail - but then it should go up/down just fine since the rail crossing under there has plastic over it (probbaly goes below the vertical rails in the mold). Anything near to proper RP-25 flanges should never touch the bottom there.

Should be easy enough to test - if the cause is the exposed bits in the one direction, the loco should not have the same issue going in the 90 degree direction to that.

Possibly the crossing is defective - the rails pas under one another with a layer of plastic between them, but if the mold didn’t get a full shot of plastic, it could be possible the weight of a loco causes the two rails to touch. Just pressing down with your fingers and no loco nearby should show if that’s a problem, if the system shorts, there’s some missing plastic.

–Randy

11

First off thank you for the replies and the welcome. I’m very new to train modeling so it’s definately been a learning experience. The Bachmann locomotives are both DCC (Alco’s 2-6-0) with full sound. When I lift the 8 drivers of the BLI off the track it continues to run, and also when I lift the tender off the track the locomotive drivers will continue to run. This is what confuses me because when it does stall on the crossing, at least 2 sets of drivers and a 4 tender wheels are still on the track (the non crossing portion). When it does stall at the exact same place at slow speeds, I took a multimeter to every spot the locomotive was on the track and was getting around 16.8-17. It seems the BLI locomotive which is alot larger than the Bachmann needs more power or something. If its worth anything, I currently only use the Bachmann E-Z controller. The smaller loco’s start up alot faster. Would it make any difference at all if I upgraded to like a Digitrax or something?

12

A more capable DCC system would allow you to better set the operational characteristics of the locos, but it won’t fix this problem. A short or a dead spot is a short or a dead spot regardless of what the power source is.

–Randy

13

Does this mean he has a keep alive in this engine?

Wouldn’t that be a function of the decoder, rather than the system?

I’m confused, if it has a keep alive, it shouldn’t stall, or at least nor immediately.

14

When I lift the 8 drivers of the BLI off the track it continues to run, and also when I lift the tender off the track the locomotive drivers will continue to run… I mentioned this because when it does stall all the drivers are not on the insulated portion of the crossing, so some electrical pickup should be happening still. Its like as soon as the tender wheels sense they are on the plastic portion of the crossing (when going slow) it stalls the entire locomotive. I did check the tender wipers and they are fitted quite well. I cleaned the tender wheels and wiped down the track with ACT 6006 and got it too actually move slow over the crossover for half a day before it started up again. Maybe this particular crossing (90 degree atlas) and locomotive just dont go well together. Thinking of trying a Peco 90 degree since the insulated plastic sections are smaller.

15

I suspect he’s referring to things like start speed and momentum - how far he has to turn the knob before the locos move, and how fast they speed up as the throttle is increased.

The EZ-Command can’t program CVs, so there’s no way to adjust the related CVs.

None of that has anything to do with the stall/short on the crossing. It should be nearly impossible for a modern style steam loco to stall on such a short dead section, especially BLI which picks up with drivers on both sides plus both sides of both tender trucks. The real question is, is it stalling because of no power, or is a short happening, which will also stall the loco

–Randy

16

It’s quite possible that You have a wheel set out of gauge and the loco is binding going through the crossing and acting like a loss of power/short. Check wheel gauge on drivers.

With no power to the rails, try sliding the engine through the crossing in every direction and see if it is binding anywhere…You should be able to feel it, if it is. Could also have a tight plastic guard rail that the wheel flanges bind going through…not enough clearance for flange. I’ve had that happen before on Atlas turnouts.

Good Luck! [:D]

Frank

17

The more info provided, the more I am leaning to a momentary short.

Check the wheelsets on the BLI against an NMRA gauge.

It can’t be a binding issue, if the sound stops as well. That is loss of power, or a short.

And, lifting only the drivers, or the tender, off the rails will not cause a loss of power to the BLI unit, as the drivers, and tender wheelsets all pick up power from both rails.

Use that NMRA gauge on all wheelsets, and on every part of that crossing.

Something is out of gauge somewhere.

18

Rick W,

I never tried it on a DCC Engine with sound…but if you had one running on any track at normal speed and you stopped it from moving with your hand…would all the power shut down, because the motor cannot turn or even spin the wheels? Just curious.

On My DC layout powered with MRC CM 20’s, I was running two Athearn BB SD40-2’s going through an older #6 Atlas turnout and all of a sudden the lead engine stopped…light was flickering and so was the pilot light on the power pack, signifying a short…I turned the throttle way up on the hand held and the second engine spinning it’s wheels pushed the first one through the turnout with some stuttering. The pilot light went back to normal and both engines continued on their way. I did it again and the same thing happened. All wheels were in gauge, the turnout track was in gauge…But…the guard rails were too tight to allow the wheel flanges to go through. I found that I had three turnouts like that…with tight clearance at the guard rails. It did act like there was a loss of power or short on the lead engine. Pushing any of the BB SD40’s thru those turnouts, you could feel it binding, enough to stop the wheels and motor from turning.

I filed the guard rails for more clearance and problem went away. I have six SD40-2’s that I woulld run together and if you have a problem with any of your trackwork…they Will find it…LOL

Take Care! [:D]

Frank

19

A few years ago I installed an Atlas 30-degee crossing and had similar problems. I found that simply pressing down on the crossing with my fingers would cause a short. I replaced the crossing with a Walthers-Shinoharas model and had no more problems. It was just a badly made piece of track.

20

Based on my experience with a BLI Mikado, it sounds like that only the rear tender truck is picking up power in the situation you mention. Check which track the rear tender is picking up power from. The locomotive wheels on that side are probably not picking up well. If the locomotive pickup is spotty then the locomotive stops when the only good pickup (the tender) reaches the plastic.

On my light Mikado the pickup was affected by the lack of springs between the axles and the frame. This can be agrevated by uneven track which lifts some of the drivers slightly.