Popular Woodworking 2002-02 № 126, страница 27
bly on a flat workbench and lay the bars across the assembly with the crowned edge down. (I label the opposite edge with the word "Up" to help me orient the bars properly.) Then clamp the ends of the bars to the workbench. The bars will flex slightly, evenly distributing the pressure from the middle out to the edges of the assembly. Applying Tension Clamps are designed, by and large, to generate compression to squeeze two boards together. But every now and then, you need some tension either to pull an assembled joint apart or to clamp a part inside a larger assembly. When I need a little tension, I rely on a set of grooved wedges. I cut the wedges from a hardwood with a slope of about 10°. If the slope is any steep CENTENNIAL FLYER UPDATE er than that, you run the risk of the wedges slipping when you use them. Make grooves in the sloping edges by cutting shallow saw kerfs down the center. Finally, make a spline to fit the kerfs. The spline should be as thick as the kerf is wide and twice as wide as the kerf is deep. To use the wedges, position them slope-to-slope with the spline in the grooves. Use a bar clamp to slide the wedges together so each wedge climbs the other's slope. As this happens, the outside edges of the wedges will push against the parts of the assembly, applying tension. PW Nick Engler is the author of over 50 books on woodworking, plus countless articles and project plans. Currently, he's helping kids across America to build ribs for a full-size replica of the first true airplane, the 1903 Wright Flyer. The ribs of the 1903 Centennial Flyer continue to come in from all over the world — one from as far away as Singapore! Once again, many thanks to the volunteers who are running the rib-building workshops and helping hundreds of young people all over this continent — and beyond — to participate in this once-in-a-lifetime project. The Wright Brothers Aeroplane Co. took a short hiatus from constructing the 1903 Flyer in September and October to travel to Kitty Hawk, North Carolina, and fly our replica of the 1901 Wright Glider that we just completed.We had some very good winds and made some surprisingly decent flights, although we found as the Wright brothers did that the 1901 glider design was lacking in lift and control. While we were on the Carolina Outerbanks, we worked with two Wright "re-enactors,"Tom Cherry (Wilbur) and David Thompson (Orville) to recreate scenes from the Wright brothers' work for a PBS documentary scheduled for release during the Centennial of Flight in 2003. Both Tom and Dave were delighted to hear news of our Centennial Flyer, and we invited them to attend our unveiling.You can see Tom and Dave flying the 1901 glider on our web site at www.wright-brothers.org. Tom Cherry and David Thompson measure the lift of the 1901 Wright Glider, recreating one of the Wright brothers' experiments. 25 FREE! WOODWORKING CATALOG Go to rockler.com/go/vl383 and order your FREE catalog today! Or call 1-800-403-9736 Check out our complete EXCLUSIVE line of jigs and shop tables for your band saw, drill press and router. PLUS thousands of other great products! ROCKLER® WOODWORKING AND HARDWARE The NEW name for... I -800-403-9736 1-877-ROCKLER www.rockler.com Circle #112 on Reader Service Reply Card IAGARA LUMBER You'll appreciate our difference. Prepaid Freight • Surfaced • Bundled Shrink Wrapped • Guaranteed All lumber is Select and better grade, 4" and wider, averaging 6"-7" in width, lengths are 6'-8'. All stock meets or exceeds National Hardwood Lumber Assoc. grade rules. All domestic lumber is Northern Appalachian grown, exhibiting characteristics of fine grain, texture and uniform color. Visa/Mastercard/Discover accepted. Niagara Lumber & WOOD PRODUCTS, INC. 47 Elm Street • East Aurora, NY 14052 Call Toll-Free 1-800-274-0397 www.niagaralumber.com Circle #143 on Reader Service Reply Card West Penn HARDWOODS, INC. Satisfaction Guaranteed • No Minimum Orders Quarter-Sawn White Oak • High Figure Curly Maple Now Also Exotic Species: Bloodwood, Bubinga, Jatoba, Spanish Cedar Padauk, Purpleheart, Zebrawood and more NEW: European Steamed Beech ALL CREDIT CARDS ACCEPTED Call for free catalog and pricing. TOLL FREE (888) 636-WOOD (9663) Code 11505 |
