Using non Leigh dovetail bits in a Leigh Dovetail Jig

[Charles Lent]

Robert,

Don't hesitate to ask if you should have any other D4R questions.

Watch the Leigh demonstration videos closely. Their method of climb cutting across the width of the cut first, and then following up with deep cuts into the jig slots makes the edge and corner of each dovetail cut nice and clean with no splintering, if done correctly.

I check in here almost every morning and will answer any future question that you have to the best of my ability and experience. I have made A LOT of dovetails with my D4R, but not so many in the last few years. I also own an FMT Pro jig and have about the same amount of use on that.

The 1/2" shank bits or the 12 mm (?) Leigh bits won't flex as much during the cuts, so the 1/2" shank is what all of my dovetail and straight bits are. I had tried a few of the 1/4" shank and wasn't at all happy with the result. Leigh recommends the larger shank bits as well.

Charley

[Robert Wachtell]

Robert,

Don't hesitate to ask if you should have any other D4R questions.

Watch the Leigh demonstration videos closely. Their method of climb cutting across the width of the cut first, and then following up with deep cuts into the jig slots makes the edge and corner of each dovetail cut nice and clean with no splintering, if done correctly.

I check in here almost every morning and will answer any future question that you have to the best of my ability and experience. I have made A LOT of dovetails with my D4R, but not so many in the last few years. I also own an FMT Pro jig and have about the same amount of use on that.

The 1/2" shank bits or the 12 mm (?) Leigh bits won't flex as much during the cuts, so the 1/2" shank is what all of my dovetail and straight bits are. I had tried a few of the 1/4" shank and wasn't at all happy with the result. Leigh recommends the larger shank bits as well.

Charley

Charley

The bits that came with my Leigh Super 12 are 8 mm bits. The Whiteside bit I bought is 8 mm as well.

Are you saying I would get a better cut with a 12 mm.

The 8 mm seemed to provide a clean cut.

One thing that seems difficult with the Leigh Super 12 is that it can be difficult to get the guide pin assembly to lay PERFECTLY flat on the work piece. It might be micro higher on one side versus the other side of the work piece ultimately causing a micro deeper dovetail cut on one end of the work piece vs the other end. Its flexible and wants to warp up or down ever so little. You can see the difference when you look at the contact to the work piece on the underside.

Also the guide pins are easily tightened in a non level position with respect to each other, even if you do push down on the center of them while tightening. Although this problem is easier to correct then the above mentioned one.

Rob

[Alex Zeller]

As far as I know the only options are 8mm and 1/2" shanks. But each requires a different guide bushing. Obviously the 1/2" shank router bits will be stiffer, but how much, I don't know. My jig came with two bushings for the 8mm bits so that's what I'm learning with. It sounds like you have the router support/ vac accessory, but if you don't you should get it. It does help. I also agree with Charlie that technique is everything. Starting with getting the guide bushing centered, not twisting the router, and how you move the router.

It would be nice to have a sheer cut or even spiral bits. I think it would reduce the tearout.

[Paul Haus]

I realize I'm late to the game here but a couple of comments for anyone looking at this later. I bought a D4R back around 2004-2005 and got a couple of bits with it. I later bought a set of bits for the jig from MLCS with 8 mm shanks and 1/2" shanks. long and short of it is I've made a bunch of dovetailed pieces and I'm more than happy with how they worked. Happens I have a couple of Bosch routers and that have an available 8 mm collet which I have.

[Dave Sabo]

8mm collets are available for just about any router, not just Bosch and Festool.