This mortising base router jig is a great add-on for your plunge router. Like most of my favorite router jigs, it is made out of acrylic so that you can easily see your start and stop lines. It is versatile enough to accommodate boards up to 10″ wide. Plus, the mortises can easily be centered or offset from center depending on your need. It is definitely a time saver when it comes to routing mortises or dados along the length of a board.

Materials

• 12″ x 8″ – 3/8″ acrylic sheet
• 2 – universal t-track (length can vary by need)
• 1 – T-track knob kit with 1/4″ bolts

Mortising base layout

I used a piece of 12″ x 8″ acrylic for my router jig mortising base. Mine is actually 1/2″ thick acrylic because that is what I happened to have handy in the shop at the time. The stated 3/8″ thick should be more than sufficiently rigid for this mortising base. The 1/2″ is almost too thick, but it still works just fine.

The slots are all 1/4″ wide to accommodate the 1/4″ bolts of the knobs. They are inset 3/4″ from each side, with a 1 1/2″ gap between them. The long slots are 5 1/2″ while the short slots are 3 1/2″. The center of the hole for the router bit is offset from the short slots by 1/2″, so the center of it is inset from that end by 4 5/8″. The mounting holes should be measured and drilled based upon your plunge router’s base.

Using the mortising base

The great thing about this router jig is that it gives you the ability to route mortises and dados in both thicker stock and thin stock. If you are mortising thicker boards, simply using t-track directly on the sides will be all you need. For thinner stock, screw the t-track into two boards with rabbits for added stability.

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