Which Axle to Drive 0-6-0T using CSB

[philchudley]

Hi All

Having reviewed the collected wisdom on CSBs is there a preference as to which should be the driven axle on a typical 0-6-0T when using CSBs? My initial thoughts would be the centre axle, given a free choice, but is there anything inheritantly wrong (or any is there any problem) in driving the rear axle if that happens to be the only choice?

Phil Chudley

[zebedeesknees]

Hi All

Having reviewed the collected wisdom on CSBs is there a preference as to which should be the driven axle on a typical 0-6-0T when using CSBs? My initial thoughts would be the centre axle, given a free choice, but is there anything inheritantly wrong (or any is there any problem) in driving the rear axle if that happens to be the only choice?

Phil Chudley

Hi Phil,
The choice of driven axle will make no difference to the behaviour of the suspension. How the motor/gearbox is hung will, however, and it ideally should be mechanically de-coupled from the chassis, so that the driven axle can move as freely as it would if it were not driven. Again ideally, the gearbox or the motor/gearbox assembly should be balanced over the driven axle and held in place by a torque reaction control link with fairly loose pivots, so that the axle is free to move in all planes without binding.

Fig 33 Here:-

http://www.clag.org.uk/41-0rev.html#section12.6 should explain.

Note that the reaction link should ideally (yet again!) be as far away from the axle (usually above) as possible, the pivot point should be above the axle line, and the link should sit in the horizontal plane. Some compromise is usually necessary...

Zeb.

[Penrhos1920]

Note that the reaction link should ideally (yet again!) be as far away from the axle (usually above) as possible, the pivot point should be above the axle line, and the link should sit in the horizontal plane. Some compromise is usually necessary...

Zeb.

For more discussion of reaction links see this topic: http://www.scalefour.org/forum/viewtopic.php?f=19&t=807

[Will L]

Having reviewed the collected wisdom on CSBs is there a preference as to which should be the driven axle on a typical 0-6-0T when using CSBs? My initial thoughts would be the centre axle, given a free choice, but is there anything inheritantly wrong (or any is there any problem) in driving the rear axle if that happens to be the only choice?

Apart from the reaction link stuff dealt with above, you need to consider:-

1. the impact of mounting your gearbox on an axle which will need to have some lateral side play as well as vertical movement. I.e. the centre axle on an 0-6-0. This may be a non problem, depends among other things, on how much clearance you have round the motor. Given a free choice I would tend to avoid it.

2. the impact on smooth running of driving the coupled wheels through a jointed coupling rod. If you do the job properly by putting a prototypical articulated joint, with no end play, in the rod, then you should be able to put your gearbox on an end axle with no problems, but, if you want the simplicity of the old dodge of jointing the rods on the centre crank pin, you would be well advised to drive from that axle.

So I suppose the answer is that there is no preferred axle to drive on, but you do need to be aware of the implications of what ever choice you make.

Will

[philchudley]

Thanks guys, your replies have cleared the issues up. I will be for sure be using proper prototypical jointed coupling rods, after conisdering the options, for the loco in question ... it will be the rear axle.

Cheers

Phil