'All axle' drive locomotives

[34theletterbetweenB&D]

I do like the (Hornby) 31 ... I dont suppose the irony has escaped others that this one in real life was an A1A type arrangment anyway

 

I often wondered what would happen if you simply remove the drive cog from the middle axle?...

 

Then you would have an A-2 2-A drive (and I expect it wouldn't pull that well). The outside axle on each bogie gets the drive, which is then passed along the bogie chassis by gear train to the centre and inside axles. But, since Hornby use a split axle construction, and the insulating ###### has the cog integrally moulded a very simple solution offers. Pull the wheels out of the ######, ream out the ###### so that the half axles are a nice sliding fit, lubricate with a little grease, return the wheels, and there is no longer drive to the centre wheels, but it still reaches the inside axle.

 

I made this mod before going DCC, having found this model a little 'coggy' at dead slow, and unable to coast with the power off unlike other similar flywheel drive types. The effect of the rubber band drive to the fan and the mismatched wheel rotations was the cause, and with these eliminated the mechanism became (and remains) a very smooth runner. Having the bogies apart also enabled correction of the excessive lateral play of the wheelsets which had the potential to take the cogs almost out of mesh.

 

For '######' read 'insulating sleeve'

[hollywoodfoundry]

I'm with Bertiedog on this, there is no reason an all-wheel drive should not work well, provided it is well designed. And as a US reader points out, they have been doing 12 wheel drive for many years and doing it successfully. Even in the real world, very few locomotive manufacturers bother with A-1-A designs, very soon realising that all powered axles were a far better design.

 

British manufacturers seem to have this obsession with only powering a few of the available axles and it is a flawed approach, as any axle that carries weight in a diesel or electric locomotive should be contributing to the tractive effort of the locomotive, be it full size or model.