Bachmann DMU, Cravens / class 105

[Bigmet]

Among Bachmann's admirable BR DMU series, this was the model for me. (I rattled around in these in my youth; how we enjoyed rides up and down to the Cross, with the forward view if the driver would oblige by leaving the blinds up. Nearly shook your fillings out, and you could hardly hear yourself speak when they were going uphill, as they were very underpowered for the work they were made to do. The watering cans on the platforms were not for the hanging baskets, they were positioned to be grabbed by the driver to refill the engine cooling system...)

But the model has none of these troubles. Looks very well, and apart from the fiddly job with the risk of breaking things to get the body off for decoder installation, is all around very good. Considering the real thing's shortfall in power, the on track perfomance of the model is ridiculously good. Finally got around to a traction test yesterday evening. It finally gave in at 15 of Bachmann's mk1 coaches. Comfortably outperforms the Bach and Hornby class 08s, close to a Heljan BTH type 1 Bo Bo (class 15). I would imagine the Derby lightweight, class 101 and 108 DMU models will all do likewise, since the drive system is the same on all.

[Bigglesof266]

Halcyon memories there Bigmet. I've got the model, and agree with you. Very nice runner, and a visual delight.

Bachmann's DMUs are a cut above.

I'd like a Derby lightweight with whiskers, but demand always outstrips supply so it commands a price premium for Bachmann.

Sometimes the world has me scratching my head in amazement though. I could't believe the price they remaindered the magnificent 4CEPs for. Must have been the regional limitation exacerbated by the 3 rail electric route limitation thing containing demand? I bought mine beforehand, but I still think they represented excellent value and are a truly good model. Another excellent runner from Bachmann.

[Bigmet]

My suspicion is that Multiple Unit models saturate the market much faster than locomotives. Partly because once you have examples of distinct types: express, outer sub, inner sub/high capacity there's not a lot more variation to lead to further sales, and - possibly more significantly - an MU needs a lot more of a continuous track space (or storage off layout) than any loco. Whereas one set of loco hauled stock can be used to represent several trains by use of different locos, which locos are rather easier to accomodate in odd corners (on layout or off).

[SRman]

You are pretty well 'on the nail' there, Bigmet.

One advantage of the 2-car DMUs is that a good many layouts can accommodate two such units in multiple, whereas with the 4 CEP units, one needs a lot more space for two units; in my case, I'm gearing my storage loops to accept two 4 CEPs plus an MLV, total 9 64' coaches. I'm well aware that many modellers simply don't have the space to be able to do this.

I recently bought a 3-car class 108 in BR blue from Hattons as one of their bargains. While I like the green better, my intentions for this unit mean that the colour was unimportant, as it is going to be wearing some blue Lima class 101 bodies in the not too distant future. Green units don't seem to come down in price as much, although there have been a few bargains in the past.

[ERMick]

As something of a coincidence, I've just bought a Bachmann 105 in BR Blue as well.

I've got the one with DCC On Board and I've just been running it on.

It runs like an absolute dream, but unfortunately I can't work out the functions for the lights at all.

F0 operates the lights on the powered car, which change according to direction, but the lights don't come on at all on the other car, plus F1 isn't bringing on the interior lights as expected.

I programmed it with both cars on the programming track. Does anybody know if there's anything else I need to be doing?

Your help would be much appreciated.

Cheers,

Mick

Edit: I've just realised the interior lights are actually coming on in the power car, operated by F0 as well, so that's not so bad I guess.

Would be very grateful if anybody could let me know how to get the lights on the other car to work as well. Ta.

[Roger (RJ)]

Has the other car got a decoder fitted?

[ERMick]

I haven't checked. To be honest I have no idea how DCC works on a two car DMU, but if it definitely needs a decoder in the other car I'll take a look.

To be honest, as I bought it with DCC On Board I would've thought it would have whatever was required to go out of the box, but there we go.

[ERMick]

Yes, the second car has a decoder in it.

I thought it probably did as there are two blanking plugs, but I've removed the body just to make sure.

So do I have to program this one separately, and if so, does it just use the same address as the first car?

Sorry for the numpty questions, as I said, this area of DCC is new to me.

[Peterm]

If you know what settings you want, how about POM (programming on the main) ?

If you do do this, you need to make sure that no other loco's etc are on the track as this method adjusts them all.

Or as you said, put just the second car on the programming track and set it up like the first one.

The only other thing that I can think of is that it's a duff decoder.

[SRman]

Yes. Program both cars on the same programming track at the same time, at least to set the address. After that, any speed/voltage and inertia/momentum settings will not be relevant to the trailer coach (no motor!), so the rest (if you wish to modify any driving settings) can be done with just the motor coach on the track.

[ERMick]

I've now tried programming both cars together, and then just programming the dummy one alone. Neither approach works.

I'm also wondering whether it could be a duff decoder, but as it's in a dummy car which has the same address as the power car (i.e. not the "normal" method for programming), I'm still quite open to thinking the problem lies somewhere in the programming method rather than the chip itself.

I've never tried POM before. I've got an Elite and I don't think it's possible with that anyway, certainly I've never seen anything in the manual suggesting that it is.

I'll carry on investigating but I think I may have to contact Bachmann to find out what the official line is.

[Roger (RJ)]

Try swapping the decoders around and see if the same problem persists or if something changes.

Programming the dummy car on its own won't normally work as there is no motor to provide an electrical load.

[ERMick]

Yay - got there!

Programming the dummy car on its own won't normally work as there is no motor to provide an electrical load.

Yep, turns out that was the problem exactly. The decoder in the dummy car just hadn't been programmed.

I swapped them round this evening and programmed the decoder from the dummy car in the power car, then put it back and all is good.

Thank you very much for all your help and replies guys, much appreciated.

[Bigmet]

I have finally got around to the full decoder equipment job on my three class 105 (two car) sets. Until now they have operated with just the motors decoder equipped. But now I have grafted on an extra plug to each of the three decoders so that they operate the trailer cars as well. Each class 105 pair is semi permanently coupled to protect the through wiring. Really objected to the thought of an extra decoder per pair simply to run the lights in the trailer car.

I have also done what I think is a clever thing (smug). I recently bought a BR blue 105 'power twin' set with pretty ghastly body damage at a low price, for the motor unit as a spares donor to maintain the other sets, and the trailer car donating its 'power car' underframe to one of the power cars in the 2x2 car set. A four car train is well within the capacity of just one motor unit for the set.

This freed a motor unit for a project I have had in mind for the expected Stirling single. I am going to build a GNR/ECJS pattern full brake to fit this motor unit, so that the Single can effortlessly haul a truly heroic train. The near windowless sides of the full brake will neatly conceal the motor within.

[Bigmet]

Just made a 'discovery' that the body for what was originally the motor equipped car doesn't clip on to the unpowered chassis it is now running on. None of the clips and detents actually match up! They go together positively enough to stay together in normal operation, but the body comes off much more easily than the 'wrestling match' of the cars as supplied.

I would have remained unaware of this were it not for a 'rough shunt' yesterday evening while making up the full six car set. That was enough to 'spring' the body off the chassis, very noticeable that the roof line didn't match.