Hello All,

The under-frames of both cars were assembled ready for test running with the electrical pick-up system unchanged from Lima's original. Rubbish running resulted because pick-up was, not to be too rude to Lima, - intermittent!

I gave a lot of thought as to why this could be and decided that the system included far too many sliding contacts; rail to wheel - wheel to axle springy-phosphor-bronze scraper - spring scraper to bogie pivot pin, the latter joint being pushed together by a coil spring. The tension of all those springy contact points would fluctuate at every track joint etc. Final y the connection to the bogie pivot pin is by a circlip, which will also be a moving joint each time that the pivot pin rotates. All of this was picking up only from a total of four wheels from a possible eight. Silly in my opinion.

Why not pick-up from all eight available wheels?

Making new bogies with full split-axle collection would do that and I would be operating in my area of knowledge. But that would be a big job! What about increasing the number of pick-up points by adding scraper pick-ups to the insulated wheels? Easier yes; but I have always been rubbish at designing and building scraper systems.

My first decision was to try to remove some of Lima's poorer areas of design. First I soldered the pivot pin to the phosphor-bronze axle scrapers and I tightened up the circlip joint by judicious squeezing with pliers. This did dramatically improve running but finger-poking was still far too frequent for my liking.

I now set off on a 'good-dose-of looking-at', with a view to making scrapers for the four wheels that Lima's system abandoned. I'm a great believer that all engineering design should deeply consider the problems of future maintenance and I want those bogies to be easily released from their under-frame but hopefully without the likely poor connection of that circlip!

That's all for now but more, with pics in a few days time.

TTFN

Good modelling to you,
Dave