I rather like my old Dublo and Triang models as you may have guessed if you've read anything prior to this. They look reasonably the part (they are at least the right colour and shape) and run well, more important however is their tinkerability. By this I mean you can strip one down no problem, re-assemble it with a modicum of care and, due to the lack of bits, 95% of the time it will run as well as the day it was made.
I decided to have a decent running session tonight on my On30 American narrow gauge layout (my main modelling concern at the moment). Everything was fine until it came to move the Bachmann railbus out of the station. It didn't, just sitting there whirring away. The final drive had gone phut.
My first fear was stripped gears, bachmann US models tend to have this affliction, due to the gear material but I'd never heard of it in this model. I opened the gearbox up and found the final drive gears had so much sideways play in them they had both disengaged, why they took so long to do this I don't know.
My solution was to slip card packing between gear and casing to keep it in mesh, this worked but now the drive was too tight and the thing struggled to move. Out came the card, but now it was making a nasty noise so I tried to remove the gearbox, failed halfway, put it back in and now it was making a truly terrifying buzzing noise.
Nothing for it, a total strip down was necessary. I dug out the exploded parts drawing and was amazed at the complexity of the thing. In the end I just started dismantling as I found it. Eventually I got to the motor casing and found the cause of the issue, I'd bent the motor tail shaft and the flywheel was now executing a spectacularly wobbly arc. I bent it back as best I could and re-assembled. It now runs as smoothly as before but any more than a scale 10 mph and the thing buzzes like a circular saw, I decided to cut my losses and leave it at that as I never run it fast anyway. I'm contemplating taking the Xuron track snippers to the shaft and just doing away with it altogether.
Detail is lovely, and this railbus has lots of it, however it makes getting the thing apart without damage impossible and I do like to have a model with ease of maintenance. I can't see models of the day running in 50 years time if the mechanisms are as awkward to look after as this one is, as people simply won't! The possible exception is the On30 mogul by Bachmann, that is a very robust model, and is part of the reason 3 of my loco's are based on them.
Dublo got it right it seems.....
I once built a 009 railbus on a Kato chassis which was basically a block of metal with axles and the commutator of the motor set inside it. All the gears were hidden (apart from the bottom of eaxh final drive pinion - the thing was 2 axle drive).
ReplyDeleteI would NEVER have attempted to dismantle it, but there was never a need - it was totally reliable (even in the harsh environment of exhibition running) it would run at any speed from dead slow to "be careful, it'll come off at the bend" and on occasions I slipped a mouse body on it and whizzed it round the circular layout for the benefit of the kids, who never believed it (until the second circuit)
As well as doing all this, it would pull a house down. On one memorable occasion on my terminus-to-fiddle-yard layout "Monyash" it actually hauled all the available stock out of the fiddle yard, setting the station operator an almost impossible task as he didn't realise how long the train was until he'd driven the railbus to the head of the headshunt!
there have been some great mechanisms over the years, unfortunately there have been some really naff ones too! The Bachmann On30 shay is a case in point, its a model I'd love but it is notorious for stripping gears.
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