Deeply Scratched and Highly Polished

Speedo Drive BracketToday saw the last of the machining operations for the Scimitar – to – Type 9 gearbox conversion with the manufacture of an aluminium bracket which reproduces the original speedo cable fitting on the later gearbox. I learned my first machining skills during school summer holidays, and it wasn’t until I reached the age of sixteen that my tuition became more formal. At that age all the engineering students – myself included – found the hand finishing of machined components to be an onerous task.  Of course, like all people “of a certain age” I am now eternally grateful that in my youth I was compelled to spend hours using emery cloth to polish the file marks from steel plate, because the task is now merely a matter of course rather than a burden. In the case of this particular item I have had to rein in my enthusiasm: Having got as far as polishing with p1200 abrasive paper, the temptation was to finish off with metal polish, but instead I have to remind myself that it would stick out alongside the rough castings of the gearbox “like a nun in a snowdrift”.

Speedo Drive

The design of the bracket is extremely simple:  It bolts onto two unused holes in the tail housing of the Type 9 gearbox and has a flat section of the correct angle and dimensions to align with the speedo drive. The drive housing on the gearbox has been fitted with a counterbored aluminium distance piece which locates the original Scimitar outer cable fitting, and the new bracket is drilled and tapped 1/4″ UNC for the fitting of the orginal forked clamp.

The conversion is now almost complete and just requires the adaptation of a suitable gearlever boot and knob to finish it off.

The rest of this evening has been spent clearing up the machine area of the workshop and filling old oil drums with all the swarf which has been produced during the conversion – let’s hope that the price of scrap steel remains buoyant…..

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