Popular Woodworking 2007-02 № 160, страница 9
Tricks of the Trade Compiled by Paul Anthony Illustrations by Matt Bantly Taper Jigsaw Blades For Tighter Turns THE WINNER: What do you do when you need to make a sharply curved scroll cut with a jigsaw, but the width of the blade causes it to bind and burn in the kerf? (On a test piece of course!) The problem is resolved simply by a quick but carefully executed taper grind on the trailing edge of the blade. A typical hollow-ground jigsaw blade is tapered slightly from front to back, but increasing the taper at the rear allows for significantly tighter turns. A 1" belt sander is perfect for this job. Be sure to hold on to the top end of the blade's shank securely with a pair of locking pliers. I hold the blade with its teeth up and tilted slightly as I press it against one side of the wheel, then the other, to create the desired taper at the rear of the blade. Remove material symmetrically from the full length of the blade, then smooth it up with some #400-grit silicon carbide paper wrapped around a small hardwood block. i >J - Standard hollow-ground taper Grind increased taper on rear section Cross-section of jigsaw blade k I've found that a 3/4"-diameter circle is about the minimum achievable with an unmodified 3/16" scrolling blade. However, after tapering, I could cut a 9/16"-diameter circle. This technique also works on the wider 5/l6" blades when I need a smaller turning radius than the factory grind will allow. Ric Hanisch Quakertown, Pennsylvania continued on page 20 CASH AND PRIZES FOR YOUR TRICKS AND TIPS! Each issue we publish useful woodworking tips from our readers. Next issue's winner receives a $250 gift certificate from Lee Valley Tools, good for any item in the catalog or on the web site (leevalley.com). (The tools pictured below are for illustration only, and are not part of the prize.) Runners-up each receive a check for $25 to $100. When submitting a trick (either by mail or e-mail) you must include your complete mailing address and a daytime phone number. If your trick is selected for publication, an editor will need to contact you. All entries become the property of PopularWoodwork-ing. You can send your trick by e-mail to popwoodtricks@fwpubs.com, or mail it to Tricks of the Trade, Popular Woodworking, 4700 E. Galbraith Road, Cincinnati, OH 45236. 18 Popular Woodworking February 2007 |
