Bachmann Mogul "Anomalies"

JimmyB

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JimmyB

Learning; but slowly!
23 Feb 2018
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New Years Day saw me laying some paving, and I thought I would run my Bachmann Mogul, a PM (battery power) towed my track cleaning wagon for a while, and on with the Mogul, which I ran for 2 - 3 hours on and off, a couple of "stutters" and a quick clean with the LGB "rubber" and all was (initially) fine. Around 3 hours later the "stuttering" became markedly worse, and with each "stutter" I notice that the rear light would flicker on. Getting dark so everything was brought in, and the wheels on the Mogul were cleaned using spirit and a cotton bud, put on my clean indoor test track with a simple LGB controller, and all seemed well. So outside (in the dark) for a "quick spin" first curcuit and all seemed well in both directions then it would hardly run, change of TE controller and the problem remained, inside and on the test track and the problem was still there, so this has ruled out both track and controller issues, tender disconnected and the problem is still there.
Next day saw a strip and clean (of the loco o_O) no signs of internal electrical issues:
Anomaly 1, tires on one side only were pretty filthy, why one side, and only after one circuit.
Tyres cleaned, and a though continuity check carried out, broken wire in one of the tender pick-ups (wouldn't help, but not a major contributor with seven pick ups a side), back on the test track and it runs pretty well especially at low speed.
Anomaly 2, the rear facing light, according to direction of travel keeps flickering on, no pattern to it, and a slight "stutter" at the same time. This is the most perplexing of the issues, and I can't say if it has always happened, and never noticed it, but could this be the cause of erratic running, and what is causing it.
 
Neil Robinson

Neil Robinson

Registered
24 Oct 2009
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No ideas regarding anomaly 1,
However with anomaly 2, presuming that the light is an led in good order with its limiting resistor, its a sign of reverse voltage spikes.
Is your controller supplying pure DC or a PWM output?
Is the motor commutator sparking and/or is its suppression O.K. ?
 
65 1057

65 1057

Railways @ 1.435 mm/ 1.000 mm/ 750 mm and 45mm
9 May 2018
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Berlin
Just to share my simple approach when I detect some anomalies:
Put pure DC directly (if possible) on the motor an let him run for a while in both directions - if OK, then check all pick-up combinations to figure out which one fails.
Just supply pure DC over the wheels A-1, A-2, A-3, A-4, then B-1, B-2 and so on.

113557_803b2e3222272e619524df8d15e110a4.png


It's pretty simple put ensures that you can exclude power pick-up-issues, before you start investigating further (controller / track / internal wiring etc.).
Hope it will help!

Andreas
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
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Just to rule-out one problem:

Does the quartering look OK?
 
LVT

LVT

Analogue automated LGB Euro on 4 loops
24 Oct 2009
160
0
Near Atlantic City NJ USA
Just to share my simple approach when I detect some anomalies:
Put pure DC directly (if possible) on the motor an let him run for a while in both directions - if OK, then check all pick-up combinations to figure out which one fails.
Just supply pure DC over the wheels A-1, A-2, A-3, A-4, then B-1, B-2 and so on.

View attachment 247222

It's pretty simple put ensures that you can exclude power pick-up-issues, before you start investigating further (controller / track / internal wiring etc.).
Hope it will help!

Andreas
Your anomaly #1 is the standard around here with my non-reversing operation. The wheels on one side get much dirtier than the others, but only after hours of operation. I presume it has something to do with current flow. What strikes me is how quickly your deposit built up. I would suggest a scrub down of your track with some sort of contact cleaner. I find that using only a dry rubbing device often redistributes the contact-blocking coating instead of removing it. Your successful slow running on clean track minimizes the possibility of a fault in the loco.
 
JimmyB

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JimmyB

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23 Feb 2018
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Many thanks so far, to answer for of the questions:
  1. As far as I know these are lamps not LED, but as I can't get to the light I can't be sure.
  2. My main controller is Aristo-Craft Train Engineer, and can be switched between linier and PWM, though I run mainly in linier, I did try both with no effect.
  3. The Mogul is not easy to run with the body disconnected, as all the connections are soldered, so can't tell.
  4. I have run continuity checks over all the wheels, however I will give the running by pair a go and see what happens.
  5. Quartering looks fine.
  6. A scrub down of the track is my next is my next task.
Again many tanks.
 
David1226

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David1226

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24 Oct 2009
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It sounds to me like it mat be a problem with the space/time continuum. I think I've mentioned this three time before, so may the fourth be with you.

David
 
JimmyB

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JimmyB

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23 Feb 2018
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It sounds to me like it mat be a problem with the space/time continuum. I think I've mentioned this three time before, so may the fourth be with you.

David
Surely this is still 5 months away
 
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Paul M

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25 Oct 2016
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Extremely Silly point, but have you made sure that the inside of the rails are clean?
 
JimmyB

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JimmyB

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Paul, not silly, but the issue is also on my inside test track, and my other locos are fine.
 
beavercreek

beavercreek

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Hi Jimmy
Is it the Bachmann Spectrum 'old time' Mogul or the smaller 'industrial' version?
You do say that it has a reverse light so it will be probably be the 'industrial' version.
Both types will have led lighting the 'old time' moguls having just the forward light.
Depending on the wheel-tyre wear, the Bachmanns do get mucky very quickly. They also can make the track black with carbon as well.
This is because of the metal and manufacture of their wheels which due to the 'rough and ready' nature tend to get carbon deposits pretty quickly. It is particularly bad if the silver coloured plating is worn through.
Also, if the track is a little damp (dew, dreary day etc), then the dirtying of the pick-up wheels can get even worse.

If it is the smaller 'industrial' version then it is pretty light and a bit of extra weight put into the boiler can help with pick-up.
 
Rhinochugger

Rhinochugger

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27 Oct 2009
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Hi Jimmy
Is it the Bachmann Spectrum 'old time' Mogul or the smaller 'industrial' version?
You do say that it has a reverse light so it will be probably be the 'industrial' version.
Both types will have led lighting the 'old time' moguls having just the forward light.
Depending on the wheel-tyre wear, the Bachmanns do get mucky very quickly. They also can make the track black with carbon as well.
This is because of the metal and manufacture of their wheels which due to the 'rough and ready' nature tend to get carbon deposits pretty quickly. It is particularly bad if the silver coloured plating is worn through.
Also, if the track is a little damp (dew, dreary day etc), then the dirtying of the pick-up wheels can get even worse.

If it is the smaller 'industrial' version then it is pretty light and a bit of extra weight put into the boiler can help with pick-up.
Jimmy's given it some weight, but the other issue with Bachmann locos - particularly the Indy mogul - is the low current needed to run them at a sensible pace. It means that they are more susceptible to dirt.
 
maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,342
7
Bucks/Oxon/Northants area
The random light flickering and stuttering sounds like a "dry" solder joint failing, a fracture in a wire or an intermittent short. Do the "indy" moguls have one of those rather overcomplicated supresors mounted on the end of the motor that have a habit of failing ? If so remove it an see if that fixes the problem. I think you are ni for a bit of methodical cause elimination work. Some of the wiring on Bachmann products can be a bit suspect. I has to re-do my Connie a few years ago because a couple of wires in the tender got together all by themselves and caused a short. Max
 
JimmyB

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JimmyB

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23 Feb 2018
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As mentioned it is the mining Mogul, with extra weight, the tyres are worn, but not badly, capacitor, didn't see one, but I wasn't looking. Not easy to run and fault find as all the wiring in soldered, no plugs! and I think a rolling road may be in order to manage this type of fault finding!! As mention did disconnect the tender to rule this out as the primary source of the fault, and when running in reverse, the front light would flicker!
 
JimmyB

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JimmyB

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23 Feb 2018
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This afternoon a good clean of my indoor test track and a run of the Mogul using my LGB 50175 (1 amp) controller. Power set at 20% of the first notch, see photo, and the loco moves along slowly, without issue. However when I move to power to zero, just before that position the rear (indirection of travel) lamp flickers, this occurs both forwards and reverse, this only occurs if I move the contoller to zero slowly.


It would seem that although track / wheel cleanliness plays a part of the issues, there is a common mode failure somewhere.
 
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dunnyrail

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dunnyrail

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25 Oct 2009
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This afternoon a good clean of my indoor test track and a run of the Mogul using my LGB 50175 (1 amp) controller. Power set at 20% of the first notch, see photo, and the loco moves along slowly, without issue. However when I move to power to zero, just before that position the rear (indirection of travel) lamp flickers, this occurs both forwards and reverse, this only occurs if I move the contoller to zero slowly.
It would seem that although track / wheel cleanliness plays a part of the issues, there is a common mode failure somewhere.
See photo?
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
22,038
32
Tamworth, Staffs.
I don't think this is a 'failure'...

My theory:
Lamps take very little current, and when running very slowly, any interruption to pickup, will cause the field to collapse in the motor windings.. This is generating a big back-emf (think car ignition coil) which is 'fooling' the loco lighting..

Probably way too over-thinking the problem, but hey-ho..
 
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Paul M

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25 Oct 2016
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I know it probably doesn't matter, but the red and blue wires are crossed. I assume that all that happens is the forward and reverse is the other way round?
 
dunnyrail

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dunnyrail

DOGS, Garden Railways, Steam Trains, Jive Dancing,
25 Oct 2009
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I know it probably doesn't matter, but the red and blue wires are crossed. I assume that all that happens is the forward and reverse is the other way round?
Yup that will be the case, often a good fix to ensure that your loco’s go right if turned to the right rather than the other natural way. Only really works on a Test Track or End to End for obvious reasons.