You Don’t Always Need A CNC

With the development of so many consumer, DIY and kit CNC mills, lathes, Laser-cutters, 3D-printers and other assorted NC machines that line our wishlists it can be easy to forget that a lot can be accomplished with manual tooling.

This is a part that was machined up mostly using hand tools after a manual lathe was used to turn the basic profile.

P1010444 P1010445   The part is a sector gear for a Holden HQ ignition. It transmits the twisting motion from the ignition key to a rack gear which locks the steering column and actuates the ignition & starter switches. This was made when the original part failed in service (mind you the vehicle was over 33 years old). A replacement was available but the lead time of more than a week would have left me without transport for too long.


The profile was copied from the original part and fabricated using a hacksaw and small hand files. The finish was achieved by glass bead blasting and still looks as good as it originally did several years later.

P1010441P1010442Now if you are wondering why the part is no longer installed, it was eventually replaced after a few years service as the nylon part will have better wear resistance in the rack and pinion use.



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