Has anyone ever designed an accurate jig for sliding dovetail joints?
Carol Reed: Yes. I did. See the book Router Joinery Workshop (Lark Books) by yours truly.
Andy Rae: There are doubtless scores of woodworkers who’ve solved this problem with cleverly designed, shop-built devices that accurately cut this joint. You’ll find one such example on page 65 of my book, The Complete Illustrated Guide to Furniture and Cabinet Construction (Taunton Press), where I describe a simple, shop-made plywood jig with tapered fences that lets you create tapered sliding dovetail sockets using a handheld router equipped with a dovetail bit. The same page shows how to cut the mating tapered dovetail pin on the router table using the same bit and two slips of veneer taped to the workpiece. If you want to make a straight sliding dovetail, you can use the same jig but without the taper, and the same router table setup without the veneer.