Machined dovetails
This article focuses on machine cut dove tails. Although they can be cut using a table saw or band saw, I find the easiest way to cut them is with a
There are several good jigs on the market. One style has a simple template attached to an adjustable base. One board fits horizontally under a clamp and the matching board goes vertically. The two pieces are cut with one pass of the router. The disadvantages of this style of jig are that it only cuts half-blind dovetails and the size and spacing of the tails and pins are fixed. This means that if your stock has to be a fixed width you can end up with partial tails or pins on the end of the board. If you don't mind the lack of flexibility, these jigs are good for making dovetails. They tend to be reliable and good workhorses.
A more sophisticated version is the Leigh dovetail jig. I love this jig. With it you can cut through, and half blind dovetails in stock of different thickness. It’s also possible to customize the spacing and size of the pins and tails to suit your project. This gives it a flexibility that is lacking in the fixed jigs. I like this aspect of the Leigh jig because it means I can custom the dovetails for the particular project I'm working on. It's also possible to buy different templates so you can make locking joints in different shapes. I've never used these, but my guess is they would be as easy to use as the standard dovetail template. The negatives of the Leigh jig are that it is expensive and it has a learning curve. I've heard people complain about how tricky it is to set up, but it comes with the best instructions, both video and written, I have ever seen on any tool. In my opinion, if you can afford it, the quality of the instructions and the jig itself make it well worth it.
There are other jigs on the market, but these are the two I’ve used. If anyone else has comments on other jigs (or these for that matter), feel free to contact me and I’ll post your replies.
A couple of things to think about regardless of the jig you are using. First, make sure and mill a couple extra pieces of stock the same thickness as your work piece. You will need these to use as test pieces when setting up the jig. These need to be exactly the same thickness as your work piece or your set-up will be off. Don’t skimp on the set up or you’ll end up taking three times as long repairing the mistakes.
Next, beware of tear-out. Tear-out happens when the router comes to the end of the board and the cutter tears the fibers instead of cutting through them. The best way to prevent this is to use a backer board, so the cut ends with the sacrificial board rather than the workpiece.
Another way to prevent this is to make a light back-climb cut on your first pass across the piece. This means you go in the “wrong” direction with the router. This is a useful trick for keeping cuts clean, but make sure and make it a light pass. If you take off too much material when back-climbing you can loose control of the router, so go easy.
Of course it also helps to have a sharp router bit when cutting dovetails. With a sharp bit, a backing board, a light back-climb pass and a well adjusted jig you should be able to cut your joints with ease. You can get more information about using routers with this link. Now, how about trying
hand cut dovetails?
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