Sliding Tapered Dovetail machines

[jt]

I've been looking for a jig to cut sliding tapered dovetails. What I've found so far is that the Porter Cable Omnijig has an add-on template and there is something called the Easy Sliding Dovetail. If my understanding is correct from reading about these and correspondence with their tech support that they are limited to creating a tenon that is 1/2" thick at most. So if I"m building a bookshelf with 3/4" think shelves and want to use sliding taperd dovetails will still nly be 1/2" think i.e when you look at the assembled product what you'd see is a shelf 3/4" think but the dovetail that holds it in place is only 1/2" thick. To me it would just look funny. Has anyone used ether of these machines? Is this correct? Are there other jigs? I'd like to find something that is adjustable for any stock thickness.

TIA

[Mike in Mystic]

I'm not sure what you mean by "sliding tapered dovetail". I know what a sliding dovetail is, but what is the "tapered" part referring to?

Anyway, I have the Leigh D4 dovetail jig, and it comes with a bar attachment that allows you to do sliding dovetails. I've not had occassion to use this at this point, but I've read the instructions and it seems straightforward. Check it out here:

(there's a link at the bottom: "how to cut sliding dovetails" which should explain things).

Mike

[j]

A sliding tapered dovetail tapers so that when yoiu first put it into the slot it is very loose and then as you seat it it tightens up. Over

18" I'd expect that the back would be maybe 1/8" thinner than the front. A tail that, once installed, looked from the outside to be 3/4 inch thick would be 5/8" thick at the back. Makes for less binding when fitting but would be as tight or thighter, due to ease of assembly, than a non taperd SD.

[Mike in Mystic]

ok, that makes sense. I guess the Leigh jig isn't designed for that. I bet you could play with the slot board to get it to work, but getting it reproducible from board to board might be tough.

Mike

[Charles Krug]

Never made dovetails, so this is just theory. . .

But what if put two guides. At the rear of the shelf, they're set to the width of your router base. At the front of the shelf, they're set to slightly larger. As the dovey bit is a side cutter, and the difference is small, you should get the desired taper.

I'd cut front and rear setup blocks with the correct size and taper in the interest of repeatability.

Not sure what you'd do with the shelf, but there ya go.

Someone with more router experience than I most likely has a better idea.

[James D Kountz]

This is a pretty easy jig you can construct yourself out of some scrap 1/4 plywood and some hardwood runners. Charles was on the right track only difference being I mounted my "guide rails" to a piece of 1/4 ply then simply clamped it in place on the bookshelf side panels. I made a similar jig with corresponding runners on top of the plywood and a fixed fence under the plywood that is then clamped to the end of the shelves to make the cut. A little fitting with a chisel was still required but Im talking very minimal here. It worked great. I think a possible improvement would be to just cut a slot in a piece of plywood with the desired taper in mind, then use guide bushings instead of fences to guide the router. Use your imagination, hard to tell what you might come up with!

Jim

[j]

James D Kountz wrote: Use your

Thanks, yea, I could invent something, been working on a design that would be easy and automatically sized to the thickness of the workpiece and allow for any depth. Jut didn't want to re-invent the wheel

jw

[Chris Merrill]

Maybe you could cut the dovetail on the router table...with the shelf standing upright. A 1/16" shim on the 'fat' end (2 shims - one on each side) would result in a 1/8" taper?

disclaimer: I'm just theorizing here...never tried it.