35 - Revolving Tool Station, страница 14

TECHNIQUE

The Raile

At this point the frame is halfway complete. But the rails won't fit the stiles yet. To produce a snug, square-shouldered joint where the rail meets the stile, you'll need to rout a mating profile on each end of the rails.

rail bit. This is the job of the rail bit. It forms a short tongue and a coped profile that allows the rail to fit into the stile.

Since the rail and stile bits are machined to be a matched set, you shouldn't have any problem getting a good fit. All you have to do is set the rail bit to the correct height.

adjust bit height. All easy way to adjust the height of the bit is to use one of the work-pieces you've already routed with the stile bit, see Fig. 2a.

By aligning the groove in the piece with the opening in the router bit, the top face of the rails and stiles should end up flush. (But you'll want to make a test cut anyway.)

Before routing the ends of the rails, there are a couple of things you can do to ensure a crisp, clean cut.

close fence opening. To keep the narrow end of the rail from accidentally catching on the opening in the fence, I "close" it with a piece of hard-board that's notched to fit

around the bit, see drawing below left.

backing board. Also, to keep the rail square to the fence and prevent chipout on the back

backing board

profile cut by rail bit "stile cut¹ edge

A A piece of hardboard with a notch to fit around the bit prevents the end of the rail from catching on the opening in the fence.

▲ To prevent chipout, use the rail bit to rout one edge of the backing board. Then fit the "stile cut" edge of the rail in the backing board.

edge, I use a backing board that's been squared up, see Fig. 2. (A chunk of "two by" material works fine.)

A backing board prevents chipout when it's resting against the edge of the rail that hasn't been routed yet, see Fig. 2 and 2b. But there's a problem when you use it to back up the edge that's been routed with the stile bit. Because of the profile on the edge, the rail won't fit tight against the backing board and the wood fibers can chip out.

To prevent this, rout one edge of the backing board with the rail bit, see drawing at left. Then j fit the edge of the rail into the profile on the backing board and rout the end, see Fig. 3.

backing board __

NOTE:

rout rail with outside face down.

rail

bit

/

NOTE:

1 align groove with opening in bit

stile

j7 backing board prevents chipout

waste

fit edge of

waste

V_

rail

backing board

router table fencf

rail i bit

carpet tape hardboard to fence

FIRST;

cut notch to fit

around bit

14

ShopNotes

No. 35