Bachmann 2-6-0 stopped dead

maxi-model

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
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I wonder If anybody can offer some advice. I have one of the Bachmann 2-6-0 Spectrum loco's, the one with all the fancy details and silver colour boiler (it's an RGS livreried one). It has only had about 6 hours running in the 3 years I have had it (from new). Before running today I oiled it up + white grease in the gearbox, ran beautifully for an hour with a modest load then came to an abrupt halt. No smoke no gridining noises, just stopped.

Checked the track power - ok no cut outs or blow fuses. Released the base plate, applied a voltage to the loco's wheels on my rollers, no movement and no noises from the motor but the "ashpan" LED's flickered normally. Checked that the motor armature could rotate and that the gearbox was not jammed - that seems ok. No apparent detached wires. Looks all a bit complex to pull apart on spec and the Bachmann site does not have the correct drawings for this loco to download or view.

Any ideas on where to start trouble shooting or is there a good loco repair person in the vicinity of Bucks/Northants/Oxon borders area who could look at it for me.

Max
 
How much grease did you put on the gears? you may have over greased it..
just something to look at :thumbup:
 
Hi there, that was quick.
I run analogue, no digital around here. The thought about too much grease had crossed my mind (and possible over oiling but the LED's seem to say that the current is getting past the wheels and bearings). What would over doing th e gearbox grease do to it to cause a stoppage? I thought I had been fairly sparing with the stuff, a couple of little squirts through the little hole in the bottom.

I'm not averse to pulling it apart. I've had my Connie apart a couple of times - loose bits in the gearbox and fried wiring - the usual grief.
 
Try getting some power direct to the motor connections to prove the motor itself hasn't died. If the motor's ok, probably a bad joint somewhere in the power path from the main board to the motor.

I thought all the 2-6-0's are basically the same design, so these diagrams on Bachmann's site should cover it?

http://www.bachmanntrains.com/home-usa/dwg/dwgs/G816X-IS001-1_BODY.pdf
http://www.bachmanntrains.com/home-usa/dwg/dwgs/G816X-IS002-2_CHASSIS.pdf
http://www.bachmanntrains.com/home-usa/dwg/dwgs/G816X-IS002-1_TENDER.pdf
http://www.bachmanntrains.com/home-usa/dwg/dwgs/G816X-IS001-2_WIRING_CONNECTION.pdf
 
Could you check the current drawn by the loco?
If excessive the grease may have entered the motor and combined with any carbon brush dust to short the motor.
If the current is low then I suspect a wire to the motor has broken or become detached from a circuit board.
Does it have a 'plug and play' socket in the tender? If so pay special attention to connections between loco and tender.
 
Thank you for the advice Nick and Phil.

It looks like I will have to take a deep breath and get the body off the chassis (just don't want to break anything) as there is very limited access from below. I doubt it is very different to the Connie in how it comes apart - a few screws near the cab, one under the smoke box saddle and don't forget to unbolt the Johnson bar.
The drawings on the Bachman site are of a very different loco that only shares a wheel arrangement in common with this one, hence my comment about the boiler. I will carry out the checks you have advised. I pray it is not a blown motor.

Such a nice little loco and looks great with an AMS Jackson Sharpe. And no, the loco really was that small.
Many thanks, Max.
 
Ok, I have got the loco apart and here is what I have found. Mounted to the back of the motor is a small PCB (Printed G814X PCB04). This as you can see has some very burnt out components! Any idea what might have caused this ? Motor runs fine but a lot of fore/aft movement in armature shaft. The gearbox and motion runs free. Grease has not vented into the motor.

What is this PCB's function and could I run the loco safely without it ? My GRS Manning Wardle does not have any fancy gubbins betwixed motor and pick-ups but then it does not have little flickering LED's and all the other parephenalia that Bachmann cram into their locos either. It would be simple just to wire it in directly.

As an alternative what are Bachmann UK (or US) like for spare parts provision. Your knowledge would be much appreciated to help me to work out how to move forward on this one.

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The suppressors are apparently to comply with Europe's tough laws on radio interference. Simply remove the circuit board and connect the motor leads direct to the motor terminals (the loco fdoes not need the board to run). If ever going the digital route then these suppressors need to be removed or the Digital control with shutdown after several minutes operation. Another example of beaurocracy gone wild.
 
Somebody like Neil R will know better than I, but to me looks like they're polarised caps I think? Don't tend to use polarised capacitors as supressors in the small scales. Plus I always thought "L" labels on PCB's were inductors but those look like fried resistors? <edit>Ah, they're RF chokes so yes, a kind of inductor</edit>

I know you said you're running analogue, but to me it looks like what happens if you put such a loco unchipped on a DCC system or AC by accident. I bit like what happens to certain Piko locos if run on DCC "address 0", from what I've read. On the other hand, maybe it's just down to a faulty component that went bad and took out the others along with it. You said you've not run the loco much from new: often if an electronic component is faulty it will fail early in it's life.

As has been mentioned, these capacitors are often/normally removed as part of DCC decoder install as they upset Back-EMF sensing. You can the leave board off anyway, but you may cause more interference to nearby TV and radio. If you really want to, then as has been mentioned you should be able to source replacement components for less than a fiver from somewhere like Maplin if you can figure out the markings on the caps and chokes. I notice the Bachmann wiring diagram for the mogul doesn't seem to show this suppression board on the motor.
 
I do not know what caused them to burn out. No shorts seen on the track, rolling stock in use/on track had insulated wheels. No other loco's on track at the time. No sudden fast running prior to stoppage, so no percieved power spike - I use Aristocraft train engineer controller with a Crest power supply, there is a cut out fuse between controller and track. Everything else still functioning well.

I was using the loco's smoke generator for the first time. Resevoir filled with fine point syringe to avoid spillage. Wiring inside boiler barrel within 6 inches of reservoir is all insulated so I don't think an accidental spillage/sepage would have caused an electrical short. In other words I'm mystified as to what has happened.

What are the functions of the capacitors and what sort of event might cause that lot to burn out without any damage to the rest of the electrics ?

Many thanks for your suggestions and information so far. As a result I'll be off down to Maplins to get the bits to rebuild the PCB anyway. I might risk running the loco with unessesary wiring parts removed - e-g between loco and tender (it can drag and get snagged on the track)
 
Ah... do you run the TE on linear or PWM? What voltage?

Some other brands of model don't like the Aristo PWM, and certainly anything with complex electronics or decoder-fitted shouldn't be run on PWM. Again from what I've read, "Best Practise" among large scale folk who run mixed brands of models with a TE seems to be to set the TE to linear mode and stick something over the switch so it cannot move.

Not sure about the Bachy Mogul, but some of their stuff isn't designed for a particularly high voltage - maybe 18v max and probably less is better.
 
maxi-model said:
What are the functions of the capacitors and what sort of event might cause that lot to burn out without any damage to the rest of the electrics ?
Click to expand...
One for a proper electronic wizz to answer in depth, but as I understand it the function of the capacitor and inductor across the motor is to smooth out and suppress the RF interference from arcing between the motor brushes and commutator as the motor turns.

If you don't think you've accidentally run the loco on AC or DCC at some point in it's life, then most likely over-voltage or a bad component in the first place. Polarised capacitors have a maximum voltage rating and also don't like to see high reverse voltages. Being a Bachmann loco I expect they'll have used the minimum "maximum voltage" they think they can get away with, if you get my meaning?

As has been said by Tim and myself, you can run the loco without the suppression but you do run the risk of upsetting the neighbours' TV's etc. if too much interference.
 
I think we might we might have got to the nub of this one. Crest transformer can output 22v/13A or 13.8v/20A. It has always been switched to the former. So I'd better switch it to the latter lower voltage. Controller set to "linear" not "PWC" output, so ok there I assume.

Luckily the capacitors still have legible printed specs still on, so trip down to Maplins still on.
Many, many thanks for your ideas and knowledgable advise. I shall effect a rebuild (I won't forget the suppressor, can't stand passing 2 strokes messing up mu digital TV reception) and let you know I get on.

Max
P.S. More input allways wellcome.
 
Good luck Max.
I hope you can identify the colour coding on the RF chokes too - they look well fried! There are different values of inductance of RF choke in the Maplin range. Perhaps need someone with a working supression board to advise the colour codes before you go off and buy stuff?
 
If it is a Crest supply, there has been some documented history of them spiking higher than the markings, 26V or so was not unheard of. There was a LONG thread on this over on MLS, but Schad recently pulled the archives....
 
If it is a Crest supply, there has been some documented history of them spiking higher than the markings, 26V or so was not unheard of. There was a LONG thread on this over on MLS, but Schad recently pulled the archives....
 
maxi-model said:
Luckily the capacitors still have legible printed specs still on, so trip down to Maplins still on.
Many, many thanks for your ideas and knowledgable advise. I shall effect a rebuild (I won't forget the suppressor, can't stand passing 2 strokes messing up mu digital TV reception) and let you know I get on.
Max
Click to expand...
I admire your attitude to the suppression issue, but if the loco were mine I'd test run it without the suppressors and see if generates any interference. If not I'd definitely leave them off.
I have no evidence to support the following opinion but I suspect the contact between rails and wheels and/or skates is just as bad a possible source of interference yet doesn't seem to be an issue.
 
As long as the loco wasn't being run at full pelt, or anywhere near, the output of the controller wouldn't have caused this. If a fault had occured with the controller and 22v was being applied then the loco would have been whizzing round your railway like the road runner on speed, unless there was a binding fault with the gearbox or similar that would have caused the speed to be limited. Try to test how much current the motor is drawing, while it is running the wheels and everything, and ensure it isn't pulling too much. To have suddenly stopped gives the idea there may have been a short between the circuit board and the motor or too much current draw. There may well have been a component failure, but ensure there is no wires with damaged insulation and (if you don't have one already) get a multimeter and test the current draw. :D
 
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