Bachmann 4-4-0 Spectrum

Eaglecliff

Eaglecliff

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How much current does one of these draw when under no particular load? Alone of all my locos - Bachmann, Aristo and LGB, even when almost stalling uphill with a full load on, it appears to be tripping the cut-out of the BTE (max load 2 amps?) every 20 feet or so.
Help please...
 
It should be only 1 to 1.5 amps on the flat. But under a full load up hill (depending on gradient) it could climb to 2 amps.
Perhaps your supply is a little sensitive but really the BTE is really rated at only 1.5 amps anyway
 
Uphill, with a load, even a minor track imperfection could cause enough drag to push consumption up by over half an amp.. And if you happen to add in a curve.. ..
 
I doubt that either of my Spectrum Moguls (similar to the 4-4-0) draw any more than 0.5 amp each in a no-load condition. I can run both with just a 1.0 amp controller without sign of power trippage.
 
I wasn't perhaps as clear as I intended to be. The 4-4-0 is cutting out on the flat virtually unladen whereas everything else - Annie and both my C-16s, early and late versions, will manage my 3% grades-on-curves, keeping their wheels turning even if they can't make the summit.
In response to an earlier query, my power supply will give 7 amps.
 
Are there are a couple of pins either side of either drivers. These are present on the related 2-6-0. While they are insulated from each other is there a possibility that they are causing/contributing to some kind of short ? It also might be worth checking wiring in the tender and the rest of the loco. I have had that problem with that related 2-6-0 loco and a Connie. Max.
 
In the first post you said that you were using a BTE (Basic Train Engineer). but in the last post you say that you are using a 7amp supply.
The BTE is only rated for 1.5 peaking at 2 amp.

The following maybe very obvious and already covered by you but ....

If your loco is giving a cutout unladen on the flat then it looks like that there is a circuit fault or even a motor problem where it draws too much power for the BTE.

Is the smoke unit running (the switch at the front of the smoke box). If it is, this could have gone 'rogue' and be pulling too much power or have even shorted (have you had the loco from new or if not the previous owner could have done an alteration in there.)

With the Big Haulers/Anniversaries, the pilot bogie can swivel around and be facing the 'wrong way' so the polarity of the pick up on the pilot is the reverse of the one on the driver wheels....so a short circuit will happen and depending on the sensitivity of the power supply it will cut out once its shorting sensor voltage has been reached.
This can also happen with the tender pick-up bogies on the Spectrum 2-6-0 and 4-4-0 if the chains have become disconnected or the bogies removed for some work etc.

Barring this obvious short there could be one in the tender itself (at the pcb or flying plug), or in the loco (at the front switch, smoke unit as mentioned previously, the pcb or the connection between the two pcbs)

I removed the two turnout 'guide pins' inside of the the drivers as these cause all sorts of problems

I do have a copy of the wiring diagram if you need it
 
Thanks for all the suggestions.
The loco is to all intents and purposes new, and has hardly been run. However, I have fiddled with the front bogie, adding weight. I will check the polarity and wiring, and then get the loco checked out with an ammeter. If all else fails, I shall call in N*** R*******!
 
It might seem a little left field but these drives are notorious for splitting the axle mounted drive gear. Is it possible that your loco is stopping because the gears are not engaging? A minor split will cause minute gear separation so that when that gear tooth is in alignment with the gearbox drive gear then the gearbox merely spins with no final drive. Are you sure that you are not associating the loco stopping with a power supply tripping out, whereas it could be that the motor is spinning but no drive.

If so then look to my thread regarding the 2-6-0 split gear issue,
 
Scratches top of pointy head. Connects digital ammeter set at Amps - 200m (milliamps?) (highest available) in circuit with 1-amp LGB 50080 transformer/controller set at half power. Lays loco on its side, touches wire to wheels, which rotate for more than previously noted stopping time. Meter reads 0.5 tops. Is that half an amp, or half of 200 milliamps?
Puts loco on bit of track, touches wire to rail. Loco moves; meter reads up to 1.0. Applies finger to loco to arrest continued foward motion; ammeter now climbs and reads about 10. Is that 2 amps? LGB, previously suspected of oversensitivity, doesn't mind so - ??
Wheels continue to rotate while ever power is applied. Presumably no gear trouble, then.
No short involving front bogie -no ohms showing.
And something else - watching valve gear, eccentrics on rhs work correctly. Eccentrics on lhs don't move as much relative to each other and the - ? - link doesn't jiggle about like the left hand one.
Needs to lie down in darkened room.
 
We both know someone who lives close to you who has both the mogul and 4-4-0 versions of this loco. You may be able to arrange to run both his and your locos on the same tracks and metered power supplies.
 
Yes, Neil, I know who you mean. Will try and get him to bring his to Walesby next month or to mine when the weather stops and see what happens. We have actually had a brief discussion but it got no further at that time. It may simply boil down to a lack of amperage from the BTE = spending some money.
Cheers.
 
While on its side if you put fingers on the wheels to slow them does it shoot up? Hard to tell from the readings you mention but if it's set at 200mA I doubt it's reading 0.5 of 200 so sounds like half an amp. Does suggest as it runs light on 2 that it's a problem when put under load only going up to 10 which is more likely to be the motor. The LGB controllers will run a little time if they try to draw too much current but then shut down. I found the twin motored LGB locos will run fine on their own but cut out as soon as you load them up one the 1 amp unit.
I bought a 20amp range multimeter when I got into the big US locos as the USA trains and aristo ones would soar under load. Helps make sure I fit correct decoders ;)
 
Eaglecliff said:
And something else - watching valve gear, eccentrics on rhs work correctly. Eccentrics on lhs don't move as much relative to each other and the - ? - link doesn't jiggle about like the left hand one.
Needs to lie down in darkened room.
Click to expand...

Sounds like your left side is out of quarter. This would put a lot of strain on the motor and cause it to pile on the amperage gobbling.
The motion should be able to move a bit (ie not be rigid) at whatever section of the rotation.
The Bachmann drivers can go out of quarter if the screw that attaches them to the axle comes loose (a common occurrence). Take off the cap that covers the centre of the wheel (you might be able to do this without taking of the rods, but it is best to take them off .... it is easy to dismantle.... note how the rods are configured if you do decode to undo them)
Under the cap will be the screw fixing the wheel to the axle. Make sure that the left side driver wheels are a quarter turn (90) in advance or behind the right ones and tighten up the screw. Then reassemble
The rods on both sides should now be easy to wiggle.
 
Same loco, new query. The “split gearwheel” syndrome has struck. A phone call to those nice people at Barwell has produced not just a gear, not just an axle and gear, but a pair of wheels, bearings, wires, axle, gearbox and valve gear all in one. I have duly downloaded a couple of “how to replace the gearwheel” articles from YouTube but they don’t cover swapping the gearbox. Counsel of perfection might be to buy a new Shortline metal gear from the US anyway and just follow the instructions, but as I’ve got the package, I might as well use it for as long as it lasts. Should I 1) attempt to swap the gearbox &c. wholosale, or 2) remove the new axle and gear from the package and replace the broken one? Don’t see any point in just swapping the gearwheel, might split it anyway.
 
Thanks for that, but isn’t the Bachmann replacement plastic? Both the sets of instructions I downloaded use the Northwest Shortline metal replacement which is specific to the 2-6-0 and 4-4-0 and costs $15 which I think is more than the Bachmann gear but avoids a repeat of the original issue?
 
Well, well. I've managed to replace the drive axle, but discovered three broken wires, one (grey) obviously from the motor, two (black, but one with a trace of red at each end) from the two-pin plug which goes to the tender. I think I've mentioned previously that this pair of wires is very short, so I probably yanked it off some time ago. I've printed a copy of the appropriate "wiring diagram" from the Bachmann website - and am neither wiser nor better informed as I cannot locate G813X-PCB04, if that is indeed where these wires should be attached. And, as the loco appears to performing correctly from an electrical point of view, what do these wires do, if anything, in a DC as opposed to DCC loco? As usual, all helpful replies gratefully received.
 
Eaglecliff said:
Well, well. I've managed to replace the drive axle, but discovered three broken wires, one (grey) obviously from the motor, two (black, but one with a trace of red at each end) from the two-pin plug which goes to the tender. I think I've mentioned previously that this pair of wires is very short, so I probably yanked it off some time ago. I've printed a copy of the appropriate "wiring diagram" from the Bachmann website - and am neither wiser nor better informed as I cannot locate G813X-PCB04, if that is indeed where these wires should be attached. And, as the loco appears to performing correctly from an electrical point of view, what do these wires do, if anything, in a DC as opposed to DCC loco? As usual, all helpful replies gratefully received.
Click to expand...

I can think of several possibilities dependent on the loco version.
They could be chuff sensors if the tender was designed for a sound card or speaker wires if a sound card was intended to be fitted in the loco. Then again they may be for a backup light, not fitted on all tenders or additional power pickups.
If your loco doesn't have sound or a backup light and has adequate power pickup I suggest you ignore them.
 
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