The Leigh FMT: When absolute precision is a must

I am in the process of building a stand-up desk. The design includes a full dust cover, which doubles as the support structure for four drawers. For the construction of the dust cover I selected 6-inch wide boards, to minimize flex of the structure under the load of the drawers and of the ribs required to keep the top from cupping (I will include all the desk design details in a future entry).

The photo sequence that follows illustrates the precision and accuracy delivered by the Leigh FMT. I decided to use double tenons along the width of the short boards in the frame, to minimize the risk of wood movement across the grain, causing cracking in the boards with the mortises. To obtain perfect alignment, the FMT allows very precise positioning of the center of each tenon and mortise. Thus, the FMT was my choice.

In this first photo I am cutting the first of two tenons:

By sliding the table on the FMT to allow centering on the second tenon, I can confidently cut that tenon:

Following some test cuts on scrap pieces, I confidently cut the mortises on the long mortise boards:

A different perspective, showing the double mortises more clearly:

The following photo shows the components of the dust cover frame; the slots in the tenon pieces and on the mortise boards will accept the ¼-inch boards that will complete the cover:

The photo below shows the first dry fit of the dust cover:

And, finally, the completed dust cover:

Alignment of the stiles (the tenon boards) was perfect on each of the rails (the mortise boards). Pretty cool!

A key to successful, repeatable results, is the clamp-on Ott table light that Sandy gave me a few weeks ago. It helps my aging eyes to perfectly align the target on the FMT to the center mark locations for the tenons and the mortises. This is what this lamp looks like – but my copy of the lamp has an arm that doubles the reach of the arm, making it very handy for use on the workbench:

I simply clamped the light to a board, and used two additional clamps to install the light on one end of the 3-1/2 inch thick workbench top. My eyes thank me for doing this. Thank-you, Sandy! True love in the shop.

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