Bachmann DMU, Cravens / class 105

[RAF96]

I have the Class 108 two car DMU in green with speed whiskers and it is a very nice model, which runs superbly.
I fitted a pair of Lenz golds as they were top of the spares box, pending getting hold of a pair of suitable sound decoders.
My only moan is the internal lights are very dim and only show up in a real gloomy room. Likely prototypical but too dim for me.

[Bufferstop]

My only moan is the internal lights are very dim and only show up in a real gloomy room. Likely prototypical but too dim for me.

Sounds absolutely prototypical. When they entered service the internal lighting was pathetic, just a few 50w bulbs. When they were refurbished and fluorescent tube lights were fitted the lighting was strong, harsh and cold! Take your pick!

[Bigmet]

I have the Class 108 two car DMU in green with speed whiskers and it is a very nice model, which runs superbly.
I fitted a pair of Lenz golds as they were top of the spares box, pending getting hold of a pair of suitable sound decoders.
My only moan is the internal lights are very dim and only show up in a real gloomy room. Likely prototypical but too dim for me.

OK, I have never had a 108 to look at, but should think the LED's used will be much the same as on the 105. The 105's interior lighting was quite bright on DC, and a very small value has been used on the Lenz decoders to turn them right down to give the impression of the original gloomth of the incandescent bulbs. Is it possible that the Lenz Golds had been set to low light output in their previous use?

[Metadyneman]

As Bigmet suggests, the lighting in the 108 is identical to that in the 105 but I have to differ with his statement that they are bright in the 105. There are two LEDs in each coach which point horizontally across a light deflecting plastic strip which is silver backed. Unfortunately the two LEDs being at opposite ends of the strip create two bright(ish) spots at each end and a very dim light in the middle section, I certainly wouldn't describe either as being overly bright. This dimness is exacerbated by the fact that the rearmost LED in the motored coach sits above the metal casing of the motor housing, so all it does is light up the inside of the roof and the top of the motor housing and provides diddly squat lighting in the back half of the motored coach. In contrast to this, the lighting in the much better designed class 101 unit has it's own dedicated pcb above the seats attached by vertical metal conducting plates clipped to the seating moulding with three LED's placed at equal intervals on the "overhead" PCB. That produces a much better and evenly spread realistic glow from the inside. Definitely a design improvement in my opinion.

[Bigmet]

That there is no daylight in my layout room influences my perception of lights on models! It's a rare OO model with lighting that doesn't have light bleed through the body shell on 12V DC when test run. Every model with lights has them turned right down on DCC, some have the function set for 'zero' output and still light up, cue felt pen on the LED or lens to 'cut it down' and/or alter the colour...

Interesting that there have been changes to the lighting arrangements on the 101 model. I was surprised in an earlier discussion on the class 108, that the wiring layout was different to that in the 105; but it all points to hints we have had from manufacturers that the mechanisms are relatively cheap to design and produce, most of the cost is in getting the external appearance design correct and the subsequent assembly and finishing to deliver correct appearance.

[RAF96]

Next time I have the bodies off I will take more notice of the 108 internal lighting. It may be a simple fix to improve the installation, but first I will check those Lenz decoder brightness settings.

[Bigmet]

Next time I have the bodies off...

Wait for a day when you are totally laid back and possessed of infinite patience... I truly like and enjoy these models, but do feel Bachmann could have made body removal a mite easier.

[RAF96]

Agreed - stuffing a decoder in there wasn’t as easy as it looked given there was a slot for it to sit on.

[Bigmet]

Did you get a resolution of the lack of lighting brightness?

[Bufferstop]

Just re-read the first post. A PAIR of sound decoders for a motor car and driving trailer? The trailer doesn't require the costly sound component. You might even get away with one where the motor output is blown.

[Bigmet]

Am I right in suspecting there were power twin class 108s? That might account for a plan to put a sound decoder in both cars

Though given the racket the bus engines made on all these early DMU's, even on a power twin just one sound decoder would be more than adequate I should think.

[Bufferstop]

In the later stages of their existence "Power Twins" were often used to cover for the policy of "one and a spare". In the three day week and the bleak days of the '70s there was a banker on standby for DMU's that weren't going to make it up the Bank at Old Hill.