I'm not the biggest fan of 35mm boring jigs because that size of hole is better suited for a dedicated machine or drill press. But, I was pleasantly surprised with Sommerfeld Tools' Easy-Bore Jig. It's a heavy-duty 3-1/2 pound cast-aluminum portable fixture that cuts an accurate Blum pattern 35mm bore along with 8mm dowel holes for press-in concealed Euro-style cabinet-door hinges.
My first impression was that its main drilling components looked similar in strength, layout and precision to what you might see on the head of a dedicated boring machine. It consists of a 35mm and two 8mm carbide-tipped bit sets in spring-loaded keyed brass bushings, which slide inside aluminum columns.
Easy to use
Each of the three hinge holes is bored using a power drill and 13mm socket placed on each columns head' and applying pressure. The 35mm bit is depth adjustable 11/32 to 17/32 inches while the 8mm bits are set for 1/2-inch depth.
An important feature is the jig's adjustable stops which set its cutting distance from the door's edge. The seven numbered settings provide a variable tab range (door edge to 35mm bore edge) of approximately 1/8 to 3/8 inch to match with Blum's recommendations for its various concealed face-frame and Euro-style cabinet hinges.
The Easy-Bore is held in place by snugging its clamping bar against the underside of a door, tightening its two knobs, then locking it down with two cam lock levers. Four friction pads on the jig help to keep it immobile.
To test the Easy-Bore, I selected a Blum Compact Face-Frame half-inch overlay single-piece hinge. First, I had to adjust the 35mm bore depth to about a 1/2 inch (trial and error), then adjusted the tab stops to setting No. 2 (be sure to tighten the stops after setting). After scribing a centerline for my bore, I then aligned it with the jigs centering V' grooves, locked the cam levers down and drilled each hole. A medium-duty battery drill was fine for the 8mm holes, but I needed to switch to a high-torque corded drill for the 35mm hole.
The Easy-Bore cut clean and tight tolerance holes in both maple and plywood. It was nice having the option of using press-in dowel type or Inserta hinges with a portable jig. Screw hinges can be used by not drilling the 8mm holes. The East-Bore is a quality product and retails for $179.00 from Sommerfeld Tools. For more information, visit www.sommerfeldtools.com.
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