Popular Woodworking 2005-08 № 149, страница 34

Power-tool Joinery

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Set the height of the cope cutter by measuring the position of the tongue.

router-table setups and two table saw setups. And to get an acceptable assembly, I actually had to use one of those old-time cordless tools - a chisel. With cope and stick, it's two router-table setups and you're done.

The trade-off (there's always a trade-off) is strength. The joint is easy to make, but it isn't as strong as a mortise-and-tenon joint.

Is it strong enough for the average frame-and-panel application? Personally, I think the joint is fine for doors on cabinets and cupboards, and for casework components. Provided it is machined accurately and glued well, it's plenty strong. If the strength of a mortise and tenon is deemed essential - for heavier assemblies such as architectural doors, for example - there are good ways to reinforce the cope-and-stick joint, such as with dowels and loose tenons.

To make a frame using this joinery, you need the proper bits and a mid-power, table-mounted router. With a few exceptions, the cope-and-stick bits can be run full-tilt in a 1¹/2-horsepower router.

Preparing the Stock

By industry convention, cope-and-stick bits are designed for ³/4'-thick stock. Because this stock thickness is standard in most areas of the United States and Canada, you shouldn't have problems if you buy dressed stock.

You do have some leeway. You can finesse the bit height setting to reduce the profile depth and increase the width of the panel-groove shoulder, or to increase the profile and reduce the shoulder. The problem when you creep below ¹^/^/16" in thickness is in fitting the sticking profile on the edge and still having enough stock to support the panel groove. As the thickness creeps above %", the problem is

Use a block of scrap to push the end of the rail into the cutter for the cope. It will prevent tear-out and give you better control.

the capacity of the cope cutter. You may find it leaves a wafer of waste attached along the stub-tenon shoulder.

For doors especially, the stock must be flat, straight and true. You can get away with using slightly bowed stock for a frame-and-panel unit so long as it isn't a door. If the wood in a frame-and-panel unit is bowed (not crooked, not twisted, just bowed), the unit will be bowed. If the unit is a structural part of the case, it will be anchored to other elements that may pull it into line and hold it there. But if it is a door, it won't hang flat, and that problem you won't be able to conceal.

Dress the chosen stock to whatever thickness you've settled on. You also need several pieces for testing the setups, bearing in mind that these particular pieces can be a secondary wood. The important thing, to me, is to plane all the stock to a consistent thickness. I achieve consistency by planing all of it at the same time.

Now rip the stock to width, then crosscut the parts to length. When you cut the rails, you have to account for the sticking width. Usually, but not always, the width is ³/8". So if, for example, you're making an 18"-wide door and using 1³/4"-wide stiles, the distance between the stiles is H¹^". But to account for the sticking, you need to add ³/4" to the length of the rails (³/8" for each stile, or twice the width of the profile).

Use one of the coped pieces to set the height for the sticking cutter.

Cutting the Joinery

If you have just purchased a bit or set of bits to do cope-and-stick joinery, I think you should spend a little time getting familiar with it. Take as much time as you need to make both cope and stick cuts. Here's your goal: a setup block with an edge sticked and an end coped. With that in hand, you can quickly set up the bits any time you need to.

The usual routine is to cope the rail ends first, then stick all the stiles and rails. So that's the routine we'll follow here.

Before doing any setup or cuts, reflect on the fact that the cope cut is cross grain. That means you need to back up the work to prevent splinters from being torn from the back edge by the cutter. Depending on the size and number of rails, I'll gang them up and feed the lot of them past the cutter, pushing them along the fence with a square scrap. The pusher acts as a backup, preventing any splintering.

Some woodworkers prefer to use a more formal guide, such as a coping sled. There's no shame in that at all. However a sled does impact the bit height setting so you have to accommodate the sled base's thickness.

The first setup task, of course, is the bit. Secure the cope cutter in the router's collet. Then establish a height setting. Knowing the industry standards, you won't be wrong to measure ⁷/16" to ⁵/8" from the tabletop (or coping sled base) to the corner of the tenon-cutter. You'll get an V8"- to ³/l6"-wide shoulder on the stub tenon.

If you already have a setup block - one that came with the bits or one you made - tuck it into the bit and adjust the bit up and down. If you are using a coping sled, you must, of course, set the block on the sled when gauging the bit elevation.

Set the fence next, positioning it with its face tangent to the pilot bearing. It helps to use a zero-clearance facing. The zero-clear

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Popular Woodworking August 2005