The Vacuum Template

How To Make Fishing Lures by Vlad Evanoff

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A vacuum template is simply a template that uses vacuum to suck itself to the workpiece. It can take one of three forms.

A. A template that mounts atop the workpiece to guide the router. The workpiece must still be clamped toi workbench in some way. All the template docs is guide the cut.

B. A template that doubles as a clamp plate. This form of template is placed over a vacuum port. The work-piece is laid on top.The vacuum is pulled, sucking the template and the work to the bench. Then you make the cut using a piloted bit (with the pilot riding on the template, of course).

C. A template that doubles as a sled or pusher. Used on a router table, this template is a lot like the first template form, except that it has some sort of handle or grip to aid in maneuvering it around the bit.

In each form, the purpose of the template is what you expect—to enable you to generate duplicate parts with relative ease. To use it, you equip your router with a guide bushing, which rides along the edge of the template, so that the bit duplicates every curve and corner as it cuts the workpiece. Or you chuck a piloted bit of some sort—a flush-trimming bit. or a piloted profile bit, or a pattern hit

with a shank-mounted bearing—in your router's collci.The bearing rides along the template's edge, guiding the cut in the workpiecc.

If you've done template work, you know the template sometimes must be between the router and the work. Other times, it must be on the opposite side of the work from the router. The former prevails when you use a guide bushing or a pattern bit. the latter when you use a standard piloted bit (including flush-trimming bits and piloted profile cutters). With vacuum clamping the template to the work, you can have it both ways.

I can't give you plans for a particular vacuum template that will have any relevance to you. obviously. There arc a couple examples shown in use. which convey

Template routing on the router table is enhanced if you have vacuum-clamping equipment. Here the edge and end of a board are being shaped with a pattern bit. The template is the base of the sled that holds the workpiece. The work is set on the template, tight against the back and end stops, and the vacuum pulled. The sled can be moved free around the bit.

the general idea, though. The essence of the job is this: Making a vacuum template is almost exactly like making a clamp plate. (See "The Clamp Plate" on page 55.) The only difference is the contour or shape of the plate. The rules that apply to making clamp plates apply to making vacuum templates.

For the template, use nonporous material. Plastic is ideal. High-quality plywood is good. MDF and particle-board are only fair and must be well scaled with a nonporous film finish.

The minimum thickness of the template depends upon the surface area of the template, upon the template material's stiffness, and upon the kind of vacuum port you are using. With a stiff plastic, a medium-sized template, and a through port, you can get by with ^-inch-thick stuff. In plywood, inch is the minimum, and % or % inch is better. Most fittings have a large diameter of l/2 inch, so trying to fit them into the edge of a '/¿-inch-thick template is perilous.

Make the vacuum template the same way you'd make any template. If you are making it to use with a guide-bushing. be mindful of offset. In all cases, make the edges as smooth as possible. Pay attention to minimum radii of inside corners. All that template stuff.

Apply the vacuum tape.This is what turns an ordinary template into a vacuum template. If you have any through holes—mortise windows, hand-grip cutouts, and the like.be sure to surround them with the tape. If the template is to fit between the work and the bench top. apply the tape to both faces.

Here's a quick but useful tip: If the vacuum chamber is vast, it's a good idea to spot little patches of tape here and there in die interior to act as pillars, preventing the template (or a thin workpiece) from bowing under vacuum. In

Vacuum hose Vacuum clamp plate Workbench

B. TEMPLATE DOUBLES AS A VACUUM CLAMP PLATE.

/-Workpiece Flush-trimming bit Jl

VACUUM TEMPLATE FORMS

A. TEMPLATE MOUNTS ATOP THE WORKPIECE TO GUIDE THE ROUTER.

Vacuum hose se

Template

Vacuum port

OR PUSHER. Sled fence

C. TEMPLATE DOUBLES AS A SLED

Sled base/template Router table

u extreme situations, a thin template (or workpiccc) can collapse onto the vacuum port, breaking the vacuum. It's an unhappy surprise for the woodworker.

Plan ahead in positioning the vacuum port. If it is a through port, you have to ask. Will the fitting and vacuum hose be in the way of the router? If it is a right angle or T-port, you have to ask, Will the bit hit the fitting?

A Vacuum Manifold

Do you like a switch on the lamp fixture? Or on the lamp cord, somewhere between the lamp itself and the plug? Do you like fumbling in the dark, finding the cord, then running your fingers along the cord until they come upon the switch?

Yeah, I like the switch on the lamp better, too. It's always there on the lamp, and knowing where the lamp is, I know where the switch is. No fumbling. I don't even have to look directly at that lamp to find the switch and flick on the light.

The vacuum manifold is the same way. My vacuum manifold, shown in the drawing, gives me several vacuum circuits, each with an on/off valve (or stop cock). I can set a series of jigs, one by one, because the manifold provides a separate on/off valve for each jig.

Sure, pinch clamps on vacuum lines do the same thing. Sure they're cheap. But finding them to open a vacuum line when you are concentrating on keeping

Using a Vacuum Template

What can I tell you about using vacuum templates that I haven't told you already? No struggling with a cartload of bar clamps and C-cIamps. Connect the template to yoti vacuum system. Position it on the work, and pull the vacuum. Then get busy with your router. It's just thai simple.

two parts in alignment is a needless frustration, like finding the Switch-on-a-Cord. The vacuum manifold, mounted next to the vacuum pump on your workbench or router table, is always there. Use it a half-dozen times, and you'll find yourself reaching out—without even looking—and turning a valve to pull a vacuum.

The nice thing about the manifold Is that it's assembled from stock fittings I bought at the local hardware store (which is no House o' Bargains). I spent roughly $20 for a two-line manifold, and I can expand it for about SI0 per line. All the fittings are for !4-inch -pipe; all are made of brass. You just screw them together and tighten 'em with a wrench. Mount the manifold beside the vacuum pump. Run a vinyl hose from the pump to the appropriate barbed connector. Run hoses from the other connectors to the particular jigs being used.

The vac-pump and manifold are constants in your system, while the jigs can be changed as necessary.

MANIFOLD ASSEMBLY

Hose to jig

Hose to jig

Turn handle 90° to open branch.

Additional branches can be added as needed.

Elbow

Nipple

Additional branches can be added as needed.

Hose from vacuum pump

Elbow

Nipple

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