40 - Vacuum Clamping System, страница 2
Issue 40 July 1998 PUBLISHER EDITOR ASSOCIATE EDITOR ASSISTANT EDITOR ART DIRECTOR SR. GRAPHIC DESIGNER SENIOR ILLUSTRATORS Donald 8. Peschke Tim Robertson Tom Begnal Bryan Nelson CaryChristensen SchultZ Roger Reiland Mark Higdon CREATIVE RESOURCES Creative Director: Ted£^:es|* •ProjectDeveloper: Ken Munkel ♦ Project Designer. Kevin Boyle • Project Coordinator. Kent Welsh * StopiW<7>-.;SteveCurti*= • Shop Craftsman. Steve Johnson • Photography Director: Lark Smothermon* Sr. Photographer: CrayolaEngland Executive Editor: Douglas L. Hk-kr- • Senior Graphic Designer: Chris Glowacki CIRCULATION Svz Swi Dirr-.. Sandy • NewBus.&&Glenda HaUtee • Renewal Mgr.: Paige Rogers • Billing Mgr.. Rebecca Cunningham • Prom. Mgr.: Rick Junking* New B us. Mgr.: Tbdd L. Bierle • Asst. Sub. Mgr.: Joy Krause • Assoc. Graphic Design Dir.. Susie Rider • Sr. Graphic Designer: CherylL. Simpson CORPORATE SERVICES V.P. of Planning &. Finance; Jon Macarthy Controller: Robin Hutchinson • Sr. Acci: Laura Thomas • Accts. Payable: Maiy Schultz • Accts Rec... Margo Petrua • Prod. Dir.. George Uhmielarz • Elect. Pub.. Douglas M. Lidster • Prod Asst: Susan Dickman • Pre-Press Image Spec.. Troy Clark, Minniette Bieghler • New Media Mgr...Gordon C. Gaippe • Multimedia Art Dir.. Eugene Pedersen • Network Admin.-. Chris Harrison • H. R. Asst.: Kirsten Koele • Admin. Asst.: Julia Fish • Recept.: Jeanne Johnson, SheryJRibbey • Blag. Maint.. Ken Griffith • Special Proj. Dir.. Saville H. Inman MAILORDER OperationsDir.: Bob Baker *Mat U Mgr. Mark Mattiussi • Cust. Service Mgr. Jennie Enos • Warehouse SwprJSTancy Johnson • Buyer: Linda Jones • Op. Asst: Tammy Aldini Tech. Rep„ MatthewTfeRonde* CustServ. Reps.. AnnaCox, Tammy Truckenbrod Adam Best, Nancy Downey: Deborah Rich* Warehouse: SylviaCare '.yQuality Control Tech n idaru Frank J( khnson ShopNotes® (ISSN 1062-9696) is published bimonthly (Jan., March, May, July, Sept., Nov.) by August Home Publishing, 2200 Grand, Des Moines, IA 5C312. ShopNotes® is a registered trademark of August Home Publishing ©Copyright 1998 by August Home Publishing. All rights reserved. Subscriptions: Single copy: $4.99. One year subscription (6 issues), $21.94. Canada/Foreign add $6 per year. Periodicals Postage Paid at Des Moines, IA and at additional mailing offices. Postmaster: Send change of address to ShopNotes. P.O. Box 371 U3e Boone, IA 50037-2103. Subscription Quest ions? Write to: ShopNotes Customer Service, P.O. Box 842, Des Moines, IA 50304-9961. Or call 1-800-333-5854, 8:00 am to 5:00 pm. Central Time, weekdays. FAX 515-283-0447 E-Mail: ShopNotes@shopnotes.CQm Internet: http://www.shopnoteK.coni PRINTED IN U.S.A. WoodNet NOW ON TW WEB! • 101 Woodworking Tips Online • Woodworking Technique!? — Step-by-Step • Pr< ijectplans you can download • WoodNet Forum — Woodworkers' Q & A • Power Tool Reviews Point your browser to: http ://www. auKUsthome. com Select "Woodworking" from the Welcome Page menu. Cutoffs It was quite an unusual looking apparatus — something you'd be more likely to find in a science lab than a woodworking shop. Made up of gauges, valves, and brass fittings, the entire assembly was mounted to a plastic base, see photo below. Running out of the side of this assembly, there was a long, flexible tube about as big around as a drinking straw. The end of this plastic tube was hooked up to what appeared to be an ordinary push block. But when I tried to lift the push block off the bench, it wouldn't budge. It was stuck tight as if it was nailed down. "So what's the deal?" I asked Ken. (Ken is our project developer). "Just part of a little experiment," he said. Then he turned a valve, and the push block released its grip like magic. FIVE JIGS. As it turns out, the push block was one of five simple jigs Ken had been working on. Each one is designed to securely hold a workpiece that's difficult (or impossible) to clamp — like when you're routing a small piece, or sanding a small part on a disk sander. But the thing that intrigues me about these jigs isn't that they hold a workpiece with an iron grip. It's that they do it without using a single clamp. VACUUM The secret to this extraordinary holding power is a vacuum (the kind that nature abhors). Each jig is designed with a vacuum area that's sealed off from the outside air. By placing a work- mm piece over this vacuum area, the outside air presses it firmly against the jig like an invisible "clamp." (Remember sucking the air from a paper cup till it stuck to your face?) Okay, paper cups are one thing. But how do you go about producing a vacuum that will hold a workpiece when a router bit is chewing into it at 20,000 rpm's? Well, it's actually easier than it sounds. All you really need is an air compressor and a special valve called a ventun valve. VENTURI valve. The most amazing thing about a venturi valve is its simplicity. Inside the valve, air from a compressor is fun- | neled past a tiny opening. As the compressed air shoots past the opening, it sucks outside air into the valve. To take advantage of this suction, one end of a tube is connected to the vacuum system. And the other is hooked up to the jig. The suction in the tube draws all the air out of a sealed off area in the jig. And that creates the vacuum. (For more on this vacuum system, see page 16.) INDEX. But the vacuum system isn't the only project we've been working on. We've just completed an updated index for ShopNotenmd Woodsmitkmagazines. (Woodsmith is our companion publication.) The index provides a complete reference to all the projects and woodworking techniques that have appeared in both ShopNotes and Woodsmith. If you're interested in purchasing a copy of the index, give us a call at 800-444-7002. ( 26 ShopNotes 40 |
