WHEN: Most Friday evenings. TIME:

07 July 2008

More on the economy transistor controller

Whilst cheap and cheerful is the name of the game for these economy transistor controllers, some concerns had been expressed regarding the long term wear associated with running the brass trigger tube on the sharp thread of a 2.5mm bolt. The test unit, packed with ceramic grease, seems fine so far but it was decided to also re look at the stock system of a 3/32 (2.4mm) tube inside the brass trigger tube. The biggest issue was to then source a 1/16 inch (1.5 or 1.6mm) bolt to support the 3/32 tube and uncle Lance of Durban Model Centre came to the rescue with the suggestion of cannibalising the "Radio Active horn" kits for the thin brass bolts and nuts. At R17 for a dual pack, yielding four bolts and eight nuts, there is little hardship in tossing out the plastic horn parts. The bolts fit perfectly in to the K&S 3/32 tubing and the vernier revealed these bolts at exactly 1.6mm diameter - perfect! This will be built in to the other Gordan unit to give a long term test comparison. The other upside is that one may be able to squeeze in the diminutive anti wobble nut without grinding a space on the bottom of the trigger.

Another issue was that it had originally been envisaged to retain the stock Parma three core cable but watching the 12 band diode unit built for Jacques/Daniel in action suggested that there may well be an element of full throttle power loss. An old article on the net on thin wire resistance had also supported this view and a visit was make to A1 radio to look for a much thicker although also cost effective alternative. There was a nice large core high strand but not uncomfortably thick clear shield dual speaker cable (part 140072) that fitted the bill at R14.95 per metre. This soft cable stripped apart beautifully, thus giving a twenty-two buck three core option. Soldered and braided lovely but obviously no where near silicon for heat resistance and life. Looks real larney, though!

All squeezed in!



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