Groove Center

US Patent # 7,997,312

Beautifully designed by Valfor Tools and flawlessly executed, the GrooveCenter represents an entirely novel way to position a router fence. It enables easy and exact placing of the router fence when making grooves, slots or mortises in the exact center of a board. More than that, it enables fail safe set up for Lock Miter Bits and Reverse Glue Joint Bits.

Watch Half-inch Shy’s review on the GrooveCenter here.

Fail safe set-up

The set-up procedure is entirely independent from the diameter of the router bit and works irrespective of the thickness or width of the workpiece.

No maths!

Whatever the dimension of a board to be routed, not a single measurement needs to be taken and no measuring tool (caliper, setup block, ruler) is required in the process. The patented sliding mechanism of the GrooveCenter ensures automatic accuracy.

Novelty approach

Eliminating the need to measure the distance between the cutting edge of a router bit and the fence, the GrooveCenter positions the fence at the correct distance from the router’s arbor itself.

Most precise and easy measurement

The router’s own arbor is, by definition, the most precise measuring point.


The GrooveCenter allows extremely precise set-up of the router fence for routing a centered slot, groove or mortise in the work piece. It also perfectly sets up Lock Miter bits and such other challenging bits as the Reverse Glue Joint bit.
These bits are frustrating to set up, but do result in a perfect and stable joint if done right.

Click on the Lock Miter Bit and Reverse Glue Joint Bit pages for a step-by-step demonstration.

The GrooveCenter places the fence at exactly the right position for any router bit. It does so entirely automatically, and irrespective of either workpiece thickness or router bit diameter.
No further measuring is required. There is no need to know the workpiece’s width or thickness to achieve perfect set up!

So: no maths, no measuring devices required!

This photo illustrates a typical layout on the router table for a centered mortise in the edge of the work piece :


This tool is unique in the woodworking market. No other device exists with the same or a similar function.

The GrooveCenter registers its position directly off the router arbor, instead of the diameter of the router bit.

When a work piece needs to be shaped in the exact middle (mortises, slots or grooves), setting the fence at the correct distance from the router bit can be a challenging process. The narrower the board, the more an off-center deviation is visible!
It requires taking account of two variables: the width of the work piece and the router bit’s diameter.

The fence needs to be positioned at a distance from the router bit’s cutting edge equal to half the bit’s diameter plus half the board’s width.

The router bit’s diameter (divided in half) is no problem. Finding the exact half of the work piece’s width is sometimes challenging when that width is not an “easy” number such as 1″, ¾”, ½” etc. (which happens when the wood is previously planed or sanded down to a “random” width), while it can also vary from one board to another in the same project.

Without the help of the GrooveCenter, the only reference point for setting the distance to the fence is the outside diameter of the router bit cutter, which in any case only only works for straight router bits: any other router bit with a profiled cutters cannot be successfully set up this way.

With the traditional set-up method, a new calculation for each change of router bit is required.

Although a test cut is always a good idea, the GrooveCenter completely eliminates the need for multiple trial-and-error passes. It, therefore, saves time and avoids wasting precious wood.

For woodworkers whose time is money, this is good news! More precision, no hassle set-up, in less time!


There is currently no other device on the market that solves all of these problems in one simple process.

Woodworkers are required to do the above-described maths and struggle to measure the distance to the fence with the help of a rule, set-up blocks or any other measuring device.

Traditionally woodworkers center a groove in the board by flipping the work piece end for end and making second pass.
This does result in a centered groove, but most of the time one that is too wide.

In case an existing groove or slot needs to be widened to an exact value, the above method of a two-way routing operation does not lead to a precise result.


$ 149.95
Please watch Half-Inch Shy’s review over the Groovecenter: