Micro-Fence - Ellipse Router Jig
The Micro-Fence elliptical router jig works in tandem with the company’s circle-cutting jig.
It’s always been a chore to make elliptical tabletops. But Micro-Fence recently introduced a jig that makes the task a lot easier. It works in tandem with a circle-cutting jig (also made by Micro-Fence) and a plunge router, allowing you to make accurate, repeatable ellipses.
At the heart of the jig is a phenolic-resin axis plate with dovetail slots milled across the face at right angles. Two UHMW (ultra-high molecular weight) plastic, dovetail slider blocks attach to trammel bars on the circle jig and ride smoothly in the dovetail slots. The circle jig provides easy adjustment for sizing the ellipse by sliding the trammel bars along parallel rods that attach to the router base.
Setup is easy. Simply adjust the trammel bars to measure half the width and half the length of the proposed ellipse. Then start routing. The blocks glide securely in the dovetail slots, allowing the router to rotate easily, so you end up with a smooth, accurate ellipse. As an added bonus, you could shorten the major-axis measurement and cut string-inlay grooves parallel to the outside edge.
The axis plate has holes for screwing the plate to the workpiece. But to avoid marring the surface, I used double-sided (carpet) tape instead.
Using the 12-in.-long guide rods that are provided with the circle jig, you can make ellipses that range in size from 19-3/4 in. by 23-1/2 in. up to 31-1/8 in. by 42-5/8 in. Larger or more elongated ellipses can be made with optional 24-in.-long or 36-in.-long guide rods. A smaller axis plate is also available. When this smaller plate is used with the 12-in. rods, you can make an ellipse as small as 15-3/8 in. by 19-1/8 in.