Guide Bushings & Adaptors
for your Router
All Leigh Dovetail & Box Joint Jigs require a router with a 1/2" collet, fitted with a Leigh
guide bushing. Your router may need a guide bushing adaptor. Click on the selector
below to determine your router adaptor requirements.
Leigh guide bushings are designed around the industry standard — a threaded bushing and nut having the dimensions shown. Some routers accept these bushings directly or come with an adaptor. For those that don’t, Leigh offers several adaptors shown in the Guide Bushing Adaptors chart below.
To determine if your guide bushing fits directly to your router, measure the opening in the bottom of your router.
The widest part, or counter bore, of the opening must be 1-3/8" and the inner hole must be 1-3/16". If the opening matches these dimensions, you do not need an adaptor. For all other opening sizes, refer to the guide bushing adaptor selector.
Guide Bushing Adaptors
for your Router
Because the router industry isn’t standardized, you may need an adaptor to fit your Leigh guide bushing to your router. Leigh offers several adaptors as shown. To determine the correct adaptor for your router, use the Guide Bushing Adaptor Selector below.
Use this Selector to determine your router adaptor requirements.
LEIGH GUIDE BUSHINGS
What Router Should I Use?
Leigh recommends a midsize router, from 1-1/2 to 2-1/4 HP (9-13 amps) with a 1/2" collet. This size provides great power to weight ratio. Fixed base routers are ideal because they have a lower center of gravity with handles mounted to the router base rather than the motor, as with plunge routers. However, if you are proficient with the use of a plunge router, it works just as well. A plunge router is recommended for Isoloc Templates and is required for the M2 Attachment. When buying a router, also consider ergonomics, switch location, a good plunge mechanism and easy, accurate adjustment of bit height.
3/8", 8mm and 1/4" bits require the use of a collet reducer, or a collet that matches the bit size. See video >
Guide Bushing Adaptors for your Router
All Leigh Dovetail & Box Joint Jigs need a router fitted with a Leigh guide bushing. Because the router industry isn't standardized, you may need an adaptor to fit the guide bushing to your router. Learn more >
Router Bottom Size Review these router base variations, accurately measure your router base and email the following to Leigh at firstname.lastname@example.org:
- a photo of the router base
- the brand/model of your router
- inside diameter of the recess for the adaptor
- distance between the screw hole centers
- depth of recess that the adaptor fits into
More on Guide Bushings
Why does Leigh use guide bushings, not bearings? Conventional guide bushings are much more versatile than shank mounted bearings. Bearings severely limit the range of board thicknesses, joint sizes and pin/tail spacing. Shank mounted bearings cannot provide the precise fit adjustments possible with Leigh’s elliptical guide bushings and the VGS.
Why does the barrel length matter? Some manufacturer’s guide bushings have very short barrels and are not recommended for Leigh dovetail jigs. The barrel length on Leigh guide bushings is .265" (just over 1/4"). Shorter barrels or barrels recessed in the router base may cause the router bit to come in contact with the finger assembly.
What is the Leigh VGS?
Leigh’s Variable Guide Bushing System was designed for use only on Leigh Isoloc Templates and F1 and F2 Finger Joint Templates, for accurate adjustment of joint fit. Learn more about the VGS.