Adjustable Finger

At the upper end of the flexibility-complexity group you'll find the Leigh jig. which has loose fingers that you can adjust. The fingers slide across the jig and back on two steel rods. The fingers can be arranged in an almost infinite number of patterns and spacings.

This actually is a template system, though glorified somewhat by the fact that each set of fingers has a side for guiding the cutting of pins and one for guiding the cutting of tails. You can set the jig to produce wide tails, narrow tails, or oddly spaced tails. It will automatically be set to produce perfectly matched pins. You want four, maybe five pins on a 16Mfr-inch-wide board? Variable pin spacing? No problem! You can set the pins as closely as 1 inch cn center and cut pins as small as Ya inch wide.

What the Leigh jig does best is cut through dovetails. First ycu clamp the tail board vertically and

Adjustable Finger Joint Jig
Individually adjustable fingers are the reason for the versatility of the Leigh jig. With the workpiece clamped in place, you align the fingers to establish the size and spacing of the pins and tails, then tighten the setscrews.

arrange the movable fingers over the end of the board to determine the spacing. Then you flip the finger assembly and rout the tails with a dovetail bit. To rout the pins, you switch to a straight bit. Hip the finger assembly again, cut a sample joint or two to get the right fit between tails and pins, then clamp the board vertically and rout the pins.

In addition to through and half-blind dovetails, the Leigh jig will help you cut box joints and, with additionalaccessories.multiplcmor-tises and tenons. To make these joints, you must use cutters that match the jig. you have to set the depth of ait just right, and a few other items have to be adjusted according to the over-100-page manual that comes with the jig. Because you have to adjust and tighten down as many as 12 separate elements, the Leigh jig is time-consuming to set up.

Obviously, this unit is for the serious woodworker who intends to cut a lot of dovetails and doesn't want to be stuck with only a couple of configurations. It'll cost you $330 plus, and you'll have to invest a considerable amount of time to get your competence up to the potential of the jig. But that done, by golly, you can cut some slick dovetails!

With the large Leigh model, you can cut through dovetails in stock up to 1 Y*> inches thick and 24 inches wide, and half-blind dovetails in stock as thick as 1 Vi inches. The small model handles only 12-inch-wide stock. A lWhorsepower router is adequate for this work, though Leigh recommends it have both Winch and Winch collets. A couple of different straight and dovetail bits are supplied with the jig. (Most bit makers sell bits specially designed for use with the Leigh jig, and getting a selection can run up the cost of routing with the Leigh jig.) Needed, but not supplied, are two guide bushings— one Mfr-inch-diantetcr and one :<i&-inch-diameter.

With the Leigh jig and the appropriate accessories and hits,you can cut flush and rabbeted half-blind dovetails, variably spaced through dovetails, compound-angled dovetails, sliding dovetails, and box joints.

Dovetail Box

variably spaced tmrougu oovetails flush half-blind dovetails box joint sliding, dovetails end-to-e.np dovetails dovïïïlv*"^0 joints produced with the leigh jig

Acrylic Assembly Jigs

DOUBLE. BOX JOINT

DOUBLE. DOVETAILS

BOX JOINT

SLIDING

joints produced with the. incra and jointech jigs

half-blind

half-bund dovetails

Angled Compound Finger Joints

Adjusting the Jointech fence is a matter of loosening the lock-down knob, depressing a button, and moving the arm while you line up the pointer with either the '/n-inch graduations on the tape or the markings on one of the interchangeable templates.

DOUBLE. BOX JOINT

DOUBLE. DOVETAILS

BOX JOINT

SLIDING

joints produced with the. incra and jointech jigs half-bund dovetails half-blind

Jr Precision Positioning Systems

With the precision positioning jigs like the Incra andjointech,you can cut flush and rabbeted half-blind dovetails, hand-cut-style half-blind dovetails, flush and rabbeted box joints, sliding dovetails, and showy joints like double half-blind dovetails.

Though not specifically dovetailing jigs, the lncra and Jointech jigs can help you rout dovetails because of their incremental accuracy and repeatability. Though they will cut half-blind and sliding dovetails, equally or variably spaced, dovetails are only a part of their repertoire. Vigorously marketed as precision, incremental positioning devices, they're tough to pigeonhole because there's nothing else quite like them.

Attached to a router table, either jig is an incremental fence positioner. You can move the fence in increments of exactly Va inch, without measuring and with a claimed accuracy of plus or minus Mooo inch. This is machine-shop precision.

Here's how the lncra jig works: Each half of the jig has a pair of acrylic, sawtooth positioning racks with a tooth-to-tooth spacing of V'» inch. Put the two halves of the jig together and the tacks interlock, meshing perfecdy anywhere along their length. You can extend or retract the end of the jig notch by notch. Each notch moves the end of the jig (and the fence attached to it) exactly Vii inch.

Central to the Jointech jig is a W inch, hardened chrome-steel lead screw with 32 threads to the inch. It has two adjustment controls. A push button disengages the indexer from the lead screw, allowing free in-and-out movement of the jig-mounted fence. This is the control you use for 99 percent of your adjustments. For micro-adjustments. a vernier thumbwheel rotates the lead screw, signalling with a click each movement of Mooo inch.

An essential element of the marketing of diese devices is the catalog of "templates" each manufacturer supplies with the device. The template is a tape strip with colored markings to tell you where to align the fence for each cut. You want to cut a "Winch double dovetail"? Slide the template into a holder on the jig and follow the markings on the template. Align the pointer with the first red line, and make a cut. Shift the pointer to the next red line, and make a cut. Do all the red-line cuts, then switch work-pieces and do all the black-line cuts. Then switch workpieccs again and do all the dotted-red-line cuts. You just

Adjusting the Jointech fence is a matter of loosening the lock-down knob, depressing a button, and moving the arm while you line up the pointer with either the '/n-inch graduations on the tape or the markings on one of the interchangeable templates.

keep adjusting the fence and making cuts as directed. Eventually, you end up with a "double-dovetail joint."

What is a double-dovetail? It's a garish three-piece joint in which a contrasting wood outlines the seam between the two principals to the joint. It's strictly for show, because it certainly doesn't fortify the joint. (If anything, it weakens it.) But for the makers of the lncra and Jointech jigs, it dramatically demonstrates the precision of their gizmo. The only place I've actually seen this joint is in their ads.

Don't let this showmanship put you off. Both the Incra and Jointech jigs do what their makers say diey do, and you can cut strong, practical joints with them.

Joints Cut With Router

variably spaced tmrouqh dovetail)

BOX JOINT

variably spaced tmrouqh dovetail)

BOX JOINT

* SLIDING DOVETAIL RABBETED BOX JOlMT

joints produced with tue omnijig

Catch Fish Ebook

Catch Fish Ebook

7 Great Ebooks About Fishing. Learn How You Can Quickly & Easily Catch a Big Fish The Right Way Even If You're a Beginner.

Get My Free Ebook


Responses

  • ANJA
    How to cut halfblind dovetails on a Leigh?
    6 years ago
  • Zemzem
    What are rabbeted halfblind dovetails?
    4 years ago

Post a comment