Article of the Month

Traction on the Cheap

So you've got that project completed, you want to give it a run and then you realise that you still have to build the power bogie - welcome to another year of waiting before running trials start.

Does the above sound all too familiar ? I've personally spent my life staring into space trying to solve that problem, and no real easy solution appeared until I did an audit of my bits box, along with rifling through Elaine's (my long suffering wife - she deals with the N gauge side of our railway partnership !) spare parts box. Two possibilities came to the surface as follows.

The N gauge motor bogie method

Thanks have to go to Colin Wilson of the Herts group for proving this one, as we had both previously thought of it, but Colin actually did it with great success. Scour the shops for an N-gauge Lima 4F or their strange 4-wheel shunter - both of these have a marvellous little Ringfield motor and gearing to two sets of wheels .... extend the axles to your desired gauge, and you have a nice little motor bogie with decent oomph if weighted correctly.

The small motor method

This one is entirely me, thanks to my spare parts audit. Hunt down those nasty cheap little motors that are meant to run on 12v (they usually scream away suggesting they were designed for 3v !). You usually find a 3-pole open-frame motor is the best type - by all means buy the motor that Hornby supply to fit their class 58 motor bogie but pay the price for the quality and name. These can be built into a small frame mounted directly on the Triang bogie with a little worm-and-wheel gearset that would dump the traction down to one axle only. As the obvious way would be to mount the motor on it's side to get anywhere near the gear-wheel, try and select a motor that fits between the wheel-sets (the Hornby one is 9.5mm wide and is perfect - I just happen to have one hanging around) so that you have the bare minimum of fooling about to do. Gears that I can recommend (if you can find them) are the small gear-sets that are built into Tenshodo motor bogies - I have acquired a few sets and they are great for any gauge (probably even Z !!).

A number of problems are likely. Lack of traction can be a problem with only one axle driven, but you can always mount the motor higher and geared through spur gears to a driving-shaft that drives all axles through worm-and-wheels - but their goes your simplicity and budget. Fast running can be solved by building two motor bogies and wiring the motors so that they are running in series - might improve traction power as well.

The obvious solution to all of the above is to set up a simple rule of thumb. Choose motors carefully and even buy a huge batch of motors so that the characteristics match. Decide how many vehicles per motor set are to be hauled - I have chosen this design on the premise that I would mount these in multiple-unit stock with one motor-set per 2 vehicles, so the 2EPB gets one set while the 4EPB and the 4CEP get two sets ..... the 3H and 6L units could be a problem though !

Sound like easy solutions ? We are probably not talking of precise mechanisms for fine scale running, but I always think back to some of Colin's EM locos that were fitted with Hornby X04's and ran like they were 5-pole or Portescap powered - get the current collection and the gearing right and it can be your dream mechanism.

Happy tinkering !

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December 1998