Leigh Dovetail Jig--Best Router?

[John Stevens]

For those of you who get good results from a Leigh DT jig, what routers are you using?

I've been trying my hand at using a Leigh DT jig for the past several weekends. At this point, I've cut somewhere between 25 and 50 sets of dovetails, both half-blind and through. While my technique has improved, I still end up with excessively large gaps in about half the tests I've run. A 50% failure rate is too high risk ruining pieces that have been milled and cut to size for furniture projects, so I've got to improve this somehow.

After speaking with Barry, the tech support guy at Leigh, I think the gaps are caused by tilting the router slightly while cutting. I've used a PC 690 fixed-base router for some of the thru-DTs, and a Festool OF1000 for the rest of the thru DTs and all the half-blind DTs. What router would you suggest?

Thanks in advance.

[John Keane]

I have not used the Leigh jib which is highly regarded among "Creekers", as is the PC 690. Festool is also highly regarded. I have used the PC and Keller DT jigs and now am using the Incra jig system. I occasionally have problems and I attribute it to an error in Technique. Dt's are a great joint in both functionality and appearance. Keep working at it and your end product will reflect your effort. Test pieces are the way to go and Pat Warner's web site is a great reference point. Good Luck.

[Andrew Ault]

Do you have a means to ensure that the collar is centered?

Pat Warner has a system to ensure a centered collar. You migh also look at his round base made for collars to help with stability.

- Andy

[Cecil Arnold]

Sounds like you have a coller problem. Once my Leigh is set up It just keeps cutting good DTs. I have a PC 350 lam. trim. that I find very useful on this tool. It's light and easy to control.

[Chris Barton]

Hi John,

I don't think it is your router. I have a D4 and use a D handle VS Bosch with soft start since a plunge router is unnecessary. I have also used my DeWalt with excellent results. I would check the following:

1.) Adjustment of the height of the bit. This can greatly influence the joint.

2.) Are you using Leigh router bits? Some other bits say they are a certain degree on the dovetail bits but can be off by a considerable amount.

3.) As others have said, your router collar needs to be exactly centered.

[Brent Smith]

Cecil,
Do you find the 310 strong enough to cut the tails. That seems like a lot of wood to remove with a small router.

Brent

[Cecil Arnold]

Not a problem. The 310 is a strong little thing. I would hesitate to try it with the 7310 though.

[John Stevens]

Hi, guys. Thanks for all the replies so far. Just to keep this thread progressing, let me address a couple of points--

1. Centering the bit and collar. One of the errors Barry and I discussed was the collar centering. It's only a problem if you're using more than one router (or if you're changing the collet height by rotating the motor when you switch bitswhen using a fixed base router for through DTs). If you're using the same router at the same height, any error in the collar centering will cancel itself out. Don't know if this is true for other DT jigs, but according to Barry, it's true for the Leigh. But for what it's worth, I make sure to get the collar as close to centered as I can anyway.

2. Adjusting the bit height. I've done enough tests to find the proper bit height for all four of the half-blind bits I'm using. The problem is that even after I find the proper height to make a joint that works, I can repeat the operation at the same bit height and wind up with joints that have gaps of over .008" which is too much according to Barry.

3. Using genuine Leigh bits. The bits are Leigh bits, 8mm shanks.

4. Clamping the pieces. Nobody has brought this up yet, so I will. A couple of times the pieces shifted and that caused gaps or joints that just wouldn't align. I've since solved that problem, so the wood stays properly aligned in the jig every time.

5. Making sure the fingers are resting flush on the work piece. This is another source of error that Barry brought up. However, it's not one that I've had a problem with.

Thanks again for all your help with troubleshooting this problem. I'm all ears if anyone has additional suggestions!

[John Stevens]

Cecil, the PC lam trimmer is on my short list of power tools to get, but for other projects. This might be a reason not to wait to buy it. What size collet are you using, 1/4" or 8mm? Can it take an 8mm collet? Thanks.

[Jim Becker]

I prefer a small, fixed base router for dovetailing with the jig...low center of gravity helps keep it from tipping and it's easier to handle than a bigger or taller unit. (For me, this would be my Dewalt DW618) But I also have the Festool OF1010 and wouldn't have an issue using it with my Leigh jig, either as an alternative or as a second router when doing through dovetails to avoid the bit changes.

[Les Spencer]

John,

I just cut half blind dovetails in 10 drawers on my Jointech. When I went to put the rabbet on the tails I noticed I was cutting approx. .010 deeper than the cut on the tails. I had not moved the bit. My only conclusion was the bit and/or the router or the Jessem router lift was growing from the heat. I slowed down (not that I would have been arrested for speeding) but the cuts started coming out flush again. This may be out in left field but I did see a difference.

[Cecil Arnold]

John, I think you are limited to the 1/4" shank on the 310, and the one complaint I've had with it is the collett which is a split cone and can jam if you overtighten. Its not been a problem, just a poor design IMHO.

[Barry O'Mahony]

Hello,

One thing I've found for thru DT's is that the setup is very sensitive to the flatness of the pins board (not so much the tails). If the board is not perfectly flat, and the the distance between the board surface and the points on the jig fingers varies, then the size of the pins will vary.

[Dev Emch]

I have cut tons of tails on a D4 and my weapon of choice is the porter cable router. I have used both the 690 and the 100. In fact, I finally found a heritage version of this router. I like the simple bushing design and it works.

Cutting tails does not require lots of gizmos and power. In fact, quite the opposite. That is why I like the porter cable 100 and 690 for this. But even the 690 is a bit heavy for driving around on the jig. The 100 is just the right size and I think DeWalt also makes a version of the 100. This thing has a yellow metal top and fixed base and has been around for years. Cutest little thing I have seen in a while. Does anyone know the model number of this little thing?

But for tips. First, no matter what you do, always cut some extra stock for test fits. Always run at least one test fit to check for fit. Second, when driving the router on the jig, keep the two handles inline and parallel with the long axis of the jig. Dont swivel the handles around ontop of the jig. If your guide and bit are perfectly centered, this does not matter. If you have some error, this technique keeps the guide bushing in the same place thoughout the cutting process. If you dont do this with a non perfect guide bushing, the bushing acts as a tiny eccentric and this can introduce some unwanted errors.

[Chris Giles]

A long time ago, I stopped using a bushing in my dovetailing operation, and went to using a live bearing on the dovetail bit shaft. I figured no matter how perfect you get the bushing in the router base, it can never be as perfect and consistant as putting a bearing right on the shaft. I use the PC690 with a 24" Omnijig, and have had flawless results for years. Two quirks of my system though, I have this router dedicated exclusively to the dovetail operation (no changing depths until its time to change to a sharper bit), and it can be difficult to find a 1/4" shank bit where the grinding allows the bearing to go all the way down to the cutting edge without a sloppy fit. I never really found a bushing system that was engineered properly to allow for all the variations between routers, bits, and joint designs. If I wish to produce some large decorative through dovetails, I use another setup and router, and reinvent the wheel again. I keep the 690 busy with my half-blind DT's, which are my bread and butter.