Leigh jigs come standard with a selection of router bits. These are designed for doing joints in timber, between 12mm and 20mm.
This is the Through Dovetail Bit that comes with the jig.
To do dovetails in material outside these thicknesses, an additional dovetail bit it needed, for materials up to 20mm. For materials from 20mm to 32mm, a combination of straight bit and dovetail bit are required.
Most of these bits have 8mm shank, which provide far greater strength than 1/4" shanked bits. There are exceptions to this, these are indicated, and require a large guide bush.
LGH-80-8 can route dovetails into material from 12.7mm to 20.5mm, to be used with LGH-140-8, which is standard with the jig. This has an OD of 12.7mm (1/2").
This bit is also used for blind dovetails.
Half blind dovetails are generally done for drawers where mechanical function of the dovetails are hidden when the drawer is pushed closed. Like dovetails, drawers have been made have been made this way for centuries.
On a dovetail jig, the tails and pins are cut at the same time with the two pieces clamped into the jig at 90° to each other.
The router bit selected should have a depth of cut at least 3mm less than the thickness of the timber being routed. This will determine the bit angle. For rabbeted drawers, the bit selected should have a depth of cut less that the rebate.
Leigh offers five half-blind bits to suit board thicknesses from 12.7mm to 22.2mm or greater.
Half-Blind Dovetail Bit Selection
Bit selection is based on the thickness material used. Ideally, select the cutter with the deepest depth of cut possible, that is less than the thickness of the material.
Each blind dovetail bit has a different angle, yet the same diameter of 12.7mm (1/2"), however each has a different depth of cut.
The below information advises the depth of cut for both single pass and variably spaced blind dovetails, and the depth of cut for the router bit. To get a tighter or looser fit, the router bit needs to be adjusted up or down, rather than the jig being adjusted.
- LGH-80-8 8° Variably Spaced Dovetails 19mm / Single Pass Blind Dovetails 10.7mm Diameter 1/2" OD, Router bit depth of cut 19.05mm (3/4")
- LGH-101-8 10° Variably Spaced Dovetails 15.8mm / Single Pass Blind Dovetails 9.1mm Diameter 1/2” OD, Router bit depth of cut 15.9mm (5/8”)
- LGH-112-8 12° Variably Spaced Dovetails 12.7mm / Single Pass Blind Dovetails 7.5mm Diameter 1/2” OD, Router bit depth of cut 12.7mm (1/2”)
- LGH-120-8 14° Variably Spaced Dovetails 11.1mm / Single Pass Blind Dovetails 6.35mm Diameter 1/2” OD, Router bit depth of cut 11.1mm (7/16”)
- LGH-128-8 18° Variably Spaced Dovetails 9.5mm / Single Pass Blind Dovetails 4.75mm Diameter 1/2” OD, Router bit depth of cut 9.5mm (3/8”)