Keller Templates
The Keller jig is unique in that it's the only one on the market designed specifically to cut through-dovetails. And it does that job beautifully. The setup is easy, adjustments minimal and the joints perfect. Company President David Keller claims, in fact, that there are no trial and error adjustments and that you get perfectly fitted dovetails every time no matter what the stock thickness – within the capability of the jig.

The pleasant fact is that the statement is only a slight exaggeration. You do have to fine tune the jig when you set it up to get precisely fitted dovetails. And you will have to repeat this procedure from time to time, such as when you have the router bits sharpened or you change the mounting blocks for the jig. But the setup procedure is far easier than the other jigs.

The design simplicity of the Keller system is what makes it easy to set up and use. There are two separate templates, one with straight-sided fingers and one with angled fingers. And there are two bits, one straight and one dovetailed. Both bits have ball bearing mounted on top of the the cutter so that you can place the templates over the workpiece and rout out exactly what you see between the fingers.

First you use the template with the straight fingers and the dovetail bit to establish the tails. Then you use the angled template and the straight bit to rout the corresponding pin sockets.

Because the straight bit and its ball-bearing guide have the same diameter, you cut out the precise are beneath the template fingers – what you see is what you cut. This is key to the function and ease of use of the jig. Because you see exactly what you cut, you can directly scribe the already cut tails onto the ends of the boards, the same way you do with hand-cut dovetails.

And for repeat work, you just index one workpiece, set up a stopblock and cut as many as you wish. Indexing the tails with the pins becomes a simple, foolproof operation, instead of a complex exercise in side-stop offsets.

The overall simplicity of the Keller system leads to benefits that are only fully realized once you start using the jig. It makes such a difference to be able to scribe the tails onto the pin stock and cut them essentially the same way you do with the hand version. For example, it's easy to adapt the jig for cutting compound dovetails. You'll need to make an angled shim similar to the one used for the Leigh jig. But with the Keller jig, it's much easier to position and clamp the shim as well as the backup blocks you'll need to prevent blowout. You'll find yourself doing much less head-scratching because you'll see exactly how the angles will be cut as you place the workpieces on the template.

Another important benefit of the Keller system is that the stock thickness can vary without any effect on how the joint fits. In the real world, this is a huge benefir. Having to dpend on uniform stock thickness is a prescription for sloppy joints unless you thickness your own stock. Also, the Keller system allow you to easily vary the spacing of the dovetails. Because the pins are scribed directly from the tails, it's a simple matter to move the template to change the spacing when cuting the tails. Then those tails are scribed onto the pin workpiece. There's no question, however, that the Leigh jig is much quicker and easier at variable spaced dovetails. You set it up once and don't have to stop and move a template during the cutting.

The Keller jigs come in three different sizes, 16 in., 24 in. and 36 inch. Each size jig comes with its own set of router bits, which are smaller or larger depending on the jig size. For more information contact Keller & Co.

Conclusion
Aside from the cost, your choice of which dovetail jig to buy will dpend primarily on the type of work you do.

If you're only going to use dovetails for an occasioinal drawer, it doesn't make sense to buy a Leigh or an Omnijig. Go with the Sears, Black & Decker or Wolfcraft. If you want to do through-doveatils, but don't need the ability to cut the half-blind version for drawers, the Keller is your best choice. It's the easiest of all the jigs to use and great for production use.