One sure sign of custom work is stopped flutes.  If the flutes stop several inches from the end of the workpiece, you can simply clamp a block to the workpiece and run the router until it hits the block.  If the flutes run close to the end, you can mark the flutes on your workpiece and just stop at the right location ... but getting the flutes equal lengths takes a good eye, a steady hand, and a lot of patience.

Or you can build this jig for a simple way to route the stopped flutes when the stop leaves the edge of the router beyond the end of the workpiece.  The heart of the jig is the two stop-bases.  One stop-base will be positioned at each end of the workpiece, so they must be built as mirror images of each other.  Each is made with three simple parts made of ½" or ¾" Birch ply.  Start with a 12x8" base, and attach a 2x4" block in the corner.  The third piece is 4x4¾", and has a series of ¼" holes drilled about 1¼" from one end.  Stagger the holes so you can place them every ¼" from the edge.

Now cut two 1½" long pieces from ¼" dowel.  Small pieces like this should probably be cut with a small handsaw.  These short dowels drop into the holes and are the stops for the jig.

Tip: If you use compressed air to clear the chips from the holes, don't blow directly down into the hole - that can actually press the chips further down.  Instead, blow the air over the hole (like blowing over a bottle to make it sing).  The Venturi Effect will lift the chips out of the hole.

Now, build an edge-guide base plate for your plunge-base router.  I recommend a rectangular base, as will register evenly against the stop pins regardless of the staggered position.  I drew a series of parallel lines on mine to help me be sure the edge guide was perpendicular to the base sides.

Now, set your stops, edge guide, and bit height for the flutes you want to run.  The setup can take some calculation, and depends on board width and number of flutes.  I highly recommend trying out your setup on a test piece first.  Set the stop-bases so that the workpiece is held in the "L" and clamp the stop-bases to your workbench.  You don't have to clamp the workpiece, because it is trapped between the router and the stop-bases.  Press the router base against the left stop pin, plunge, and move the router until the base hits the right stop pin. 

Note: Try not to dwell at the start and stop locations because burns can be very hard to sand out of the flutes.

Unless you are making a center flute, you can just flip the workpiece 180 degrees to make the matching flute down the other side.  If you are making fluted molding of different lengths, but with the same stop pattern, you can just move one of the stop bases to adjust for the different length of workpiece. 

The few minutes required to build this jig will be paid back many times over with accurate and repeatable stopped flutes.

Tags: router, flutes, fluted, stopped, molding, jig

Categories: Jigs & Tools