Sunday, June 7, 2009

Its Log!

Our Education Department was hosting a family workshop for making clocks out of slices of logs, and wanted a way to treat the face of the clock so that it was more attractive than the rough-sawed wood.

I devised a system where we could dish-out the face of the log 0.75" and leave the bark and last few growth rings intact. In preliminary test this outer ring would blow apart during fly-cutting the entire surface.

I created a holding jig with a 90 of hardwood and a couple of De-sta-co clamps.

At the 90 and 180 degree quadrants I installed some screw tips peeking out.

The log was tapped against the exposed screws and clamped.

I created a tool path based upon the smallest log diameter, and printed off a centering template to be placed on the fixtured log.

With the template in place, I locate the tooling over the center of the template and zero my x and y axises. Then the tooling is zeroed to the surface of the log using the z-zero plate. Run time was about 5 minutes each.

Here is the finished product. The hole for the clock mechanism was made using a forstner bit on a drill press rather than using the 'Bot. If I was making a a few hundred of these rather than 15, I might have expended the extra effort to make jig for the CNC machine. It did not make sense to expend that effort in this instance.

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