Friction Drive 'Imp'

This is our competition winning locomotive! Built by Rupert as the KLR entry for the 'Minimal Gauge Railways' Facebook group Locomotive Building Competition 2016. The brief was "to build the sort of simple loco that anyone could build." It was emphasised that "it really does need to be simple and straightforward and very modestly priced to get hold of the materials and do whatever you need to do to turn them into a locomotive". Click here to read the competition rules/guidelines in full.

As you can see from the picture, the chassis and body are made from wood. Power is provided by a small lawnmower engine. All the components used are easily available and can be assembled using a modest selection of DIY tools and skills.

Perhaps the most unusual aspect of this locomotive is the friction drive and the way it is engaged. Instead of using a gearbox, a disc mounted on the drive shaft transmits motion by surface friction to one or other of two discs mounted at right angles to it. Selecting one disc gives forward motion, whilst selecting the other gives reverse. Which disc is selected is determined by moving the whole engine unit laterally so that the drive disc makes contact with the appropriate driven disc. This method of power transmission is explained fully in the build file available below.

Part of the competition was to write up what materials you used, from where you obtained them and for how much. This information is provided in the KLR_Imp_parts.pdf which is available for viewing/download below. In addition a write up (with dimensions) and photographic record of the build to help others follow your lead was requested. This write up is available for viewing/download as KLR_Imp_build.pdf .

KLR_Imp_build.pdf KLR_Imp_build.pdf
Size : 1760.99 Kb
Type : pdf
KLR_Imp_parts.pdf KLR_Imp_parts.pdf
Size : 74.423 Kb
Type : pdf

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