Woodworker's Journal 1993-17-4, страница 10

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ou can't help hui no-lice the eye catching advertisements for the Incra Jig. The pictures showing an array of intricate joints in bright contrasting woods are hard to ignore. But just what is the Incra Jig and what can it do'.'

What Makes It Unique The Incra Jig is a precision linear positioning device incorporated into a uniVersa! fence system. The unit is intended primarily for use on a router table but can also be used with a table saw, drill press or any other tool that normally uses a fence for positioning.

The heart of the jig is a set of mating, cast-plastic saw tooth racks. Precise and re-pcatable positioning can be achieved within the tooth pitch increment of the racks. This means that tlie fence can be positioned to within the pitch distance and locked without slippage.

With this precision in fence location, a series of templates (actually single purpose specialized scales) can be used to

INCRA JIG PRO

bx Dennis P res ion

Incra Jig Pro villi optional Pro Fence and Right Angle Fixture. Shown in use on router table

identify fence positions for making a variety of joints. Modular System

The Incra Jig is a modular system, enabling you to add accessories as you need them. In this ev aluation I used the 16 in. Incra Jig Pro. the 2X in. Pro Fence w ith stop, the Incra Mike, the Right Angle Fixture, and the Master Template Library. I'll discuss each of these in turn.

Incra Pro: The Incra Jig Pro is an improved version of the original Incra Jig and is the fundamental element of the system. The basic parts (other than the racks) are made of aluminum extrusions, and consist of a stationary base and the movable tup. Tlie mating racks are mounted to the base and top, and a fence mounting bracket is also included. A large cam clamp permits rapid locking and unlocking of the top at the desired location. Tlie standard racks (and those on the lest unit) have a 7X in. pitch spacing; a 1 millimeter pilch spacing is also available. The racks are quite durable, and carry a lifetime w arranty against damage for any reason.

Depending on the height of the fence you use. you may need

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to add a ply wood base plate, as shown in the photo. You provide the plywood.

A set of templates arc provided that slide into a recessed slot in the top half of the jig and provide a reference for fence positions, depending on the joint configuration selected. A movable hairline cursor allows you to precisely sei the fence position with respect to the base.

Incra states that positioning accuracy is within 0.004 in. I could not verify the accuracy, but using a machinist's dial indicator. I measured repeatability (moving the fence from one position to another and back to the original position again) to within 0.00] in. Certainly close enough for woodworking! The suggested retail price for the Incra Jig Pro is S&9.95.

Incra Pro Fence with Slop: You can make your own fence or use the Incra Pro Fence. The Pro Fence fastens to the mounting bracket on the sliding top. It comes with an adjustable stop and incorporates the same rack system as the Incra Jig for repeating fence stop positions. Additionally, the fence incorporates a groove for the right angle jig. and has a notch machined in the bottom center for router bit clearance.

The Woodworker's Journal