Nuts and Volts - September 2011

www.nutsvolts.com/index.php?/magazine/article/september2011_Collier

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■ FIGURE 2. Assembly detail; see Table 1 for component identification. (Bottom side shown facing up for clarity.)

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and the assembly drawings in Figure 2. Locally available common parts — such as fasteners and aluminum bar stock — are not included in the list. The only special tools required for construction are thread-cutting taps of several different sizes, and the corresponding tap drills. The part numbers shown in Table 2 are for spiral point taps, a.k.a., “gun taps,” which can be used in a reversing power drill or drill press. First, cut the extrusions to length as indicated. A hacksaw cut would be sufficient, but most power miter saws can cut aluminum and provide a much cleaner result. In order to assemble the frame using the extrusion connectors, the ends of the 10” pieces need to be threaded 1/4”- 20. The hole through the center of the extrusion is already the proper diameter to be tapped this size. Figure 3 shows the usage of the extrusion connector;

1/4” diameter holes should be drilled 1/2” from the ends of the non-tapped extrusions to provide access for a 5/32” hex wrench to tighten the connector. Note that the T-nuts must be inserted before the frame is assembled: four on the top side for the knobs; four on the bottom side for the feet; and two on the front side for the rotating side supports. Plastic end caps are available which cover the exposed ends of the extrusion, mainly for cosmetic purposes.

The leveling feet and toggle clamps can

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T-nut, 1/4"- 20 thread

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be attached to the bottom side once the frame is assembled. Install a washer and nut onto each foot stud before threading it into the T-nut; this will allow the feet to be adjusted individually so that the jig sits flat on your work surface. The mounting holes in the toggle clamps don’t line up with the T-slot, so they will need to be screwed down. Position each clamp and mark the hole locations, then drill and tap partially through the extrusion for #8-32 thread.