Rebarreling and Home-Shop Machining

Jig boring is using dial indicators or feed-wheel dials to accurately place holes in a part.  I made this set of parts for an RC car using 6061 T6 temper Aluminum plate that was 1/4 inch thick.  I have two dial indicators on both the x and y axis to accurately locate the holes in the part.  All holes where center drilled and then through drilled.  Two of the holes were then countersunk at 82 degrees from the bottom side. All cuts were made in the tilting milling vise.  I made the angled cuts by setting my dial protractor to 12 or 18 degrees, setting it on the part, and then tilting the vise using a Starrett bubble level (from the combination square) on top of the dial protractor  until the bubble leveled out.  This was sufficient accuracy for this part.

To make the cut on the backside, I used two of the screw holes and drilled and tapped a thick piece of steel plate at right angles to the part.  I then screwed the part to the steel and clamped the steel plate in the vise.

I finished the part smooth by hand, then used the same bead blast equipment that is described elsewhere in this Jouranal.  The part came out nice.

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