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Forum topic by Gerald Thompson posted 12-09-2019 08:23 PM 320 views 0 times favorited 11 replies Add to Favorites Watch
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Gerald Thompson

1234 posts in 2842 days

12-09-2019 08:23 PM

I am having a terrible time getting acceptable results using the directions in the user’’s guide.
It should be fully understood that I have a very limited mechanical mind. I’m not crying the blues that is just a matter of information. I am past doing things backwards which I expected and dealt with.
I am using two fixed base Bosch 1617 routers with two 7/16’’ guide bushings and No. 80-8 bit and No. 140-8 bits each in separate routers.
When I adjust the the fingers on the TD Pin mode to adjust for fit I notice the bit only removes wood on the right side. The two boards fit together but remain a little sloppy and I either get things a little too tight or just a little sloppy. I have moved the finger assembly infinitesimal amounts but I still get wood removal only on the right side and unacceptable fits.
I am using BORG pine boards 3/4’’ until I get a snug fit and will move on to hard wood to tune it up if needed.
Could there be a concentric problem? I used a device that came with an aftermarket base plate and have another one coming as it appears to be more sturdy.

Thank you.

-- Jerry

11 replies so far

View pintodeluxe's profile


6038 posts in 3421 days

#1 posted 12-09-2019 10:14 PM

I’ve been through the problems and fixes on all different brand dovetail jigs. The Achilles heel of the Leigh system is the variable diameter guide bushing. It works (sort of) as long as you don’t rotate the router. Sounds like you’re using a fixed diameter guide bushing, and making adjustments on the jig. That’s a fine way to go.

Interestingly the worst days I’ve had with my Leigh jigs (I have three) were with a Bosch router and aftermarket sub-base. So make sure you’re guide bushing is centered on the router. Also, not all guide bushings are created equal. Some are machined perfectly round, and that’s the type you need for dovetails. I get the brass ones from Whiteside. I’m not sure the metal process on the other type of bushing, if they’re stamped or cast, but the machined ones are more accurate. Whatever you use, check the lip of the guide bushing to make sure it is within .001 of stated size, and that it is a true circle.

Of all my brands of jigs, I get the worst results with the Leigh. It boils down to the individual fingers not laying perfectly flat. It causes discrepancies that are transferred to your work. That, and the inherent weakness in the E-bush. I mean it boggles the mind how bad of a system it is.

Surprisingly, I get spot-on results with the little Porter Cable jig, however it’s limited to fixed spacing.
For variable spaced dovetails I use an Akeda jig. Sadly it’s not being made right now, but it fixed all the issues I had with the other jigs. Just an absolute pleasure to use.

So I would say focus on checking that your guide bushing is true, and re-centering the guide bushing on the router. Also, switch over to hardwood scraps. Softwoods are a whole different game.

Finally… and this is a big one… only make one pass on each part. What I mean is don’t rout a part, then make jig adjustments and cut it again. Instead use scraps to test the jig setting. If it doesn’t fit, cut the end off the scrap board and try again. Especially if you re-position the board in the jig, it’s just asking for fitment issues.
Good luck!

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

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Gerald Thompson

1234 posts in 2842 days

#2 posted 12-09-2019 10:24 PM

Thank you. I will start the elimination process tomorrow.

-- Jerry

View BurlyBob's profile


6912 posts in 2873 days

#3 posted 12-09-2019 10:28 PM

Jerry, do I ever remember the issues I had getting use to my D4. That jig is terribly unforgiving. I had to get it right down to a gnat’s a$$. I had trouble with the wood moving in the jig and ended up applying wet/dry sand paper to all the contact points.. That seemed to help greatly. One thing I also learned that you can rotate the router the least little bit during a cut. Also the bit had to centered exactly. Man it was just one thing after another. I even had to deal with router bits torgueing out of the collet. I called the company and didn’t get what I thought was very helpful assistance. I remember the guy telling me something like, it’s all in the geometry. That was super helpful.

I did get some helpful advice from Fred Hargis. He might be a good resource for you.

Best of Luck.

View Redoak49's profile


4355 posts in 2596 days

#4 posted 12-09-2019 10:30 PM

I assume you are making through dovetails.

One suggestion is to make certain the router bits are centered in the bushing.

I do not try to adjust a fit on an already routed board but make an adjustment and rout a new board.

The fit adjustment is made by changing the position of the finger setup in and out. Make certain both ends are in the same position and record the positions and result with each try.

A couple of other things I backgrounds to check carefully that the board is correctly aligned. I put adhesive backed sand paper on the bars that clamp the piece.. I also added a center tightening clamp to both bars. You want to be certain your board does not move.

Take a deep breath and follow the instructions and videos. I have made many dovetails with mine..It works but takes a bit of learning.

View Fred Hargis's profile

Fred Hargis

5929 posts in 3101 days

#5 posted 12-10-2019 01:22 PM

Any jig as versatile as the Leigh DT jig is going to be a little tough to use. I started over with mine and went back and reset everything from scratch using the manual as a guide. After that I made sure my bushing was perfectly centered around the router bit (very important). Than I found sliding the router across the fingers was not s smooth as I wanted…I waxed my router base plate and took extra care to keep the router steady as I worked across the fingers. I’m able to get perfect DY joints with this, but as a last resort i can tell you Leigh is very helpful if you have a specific question/problem. They’ve heard it all and will probably have the solution right off the top of their head. That said, my jig doesn’t get daily or even monthly use….every time I use it I go through the learning process again.

-- Our village hasn't lost it's idiot, he was elected to congress.

View EarlS's profile


3430 posts in 2955 days

#6 posted 12-10-2019 01:52 PM

I’m getting ready to use a retrofitted D4R Pro for the first time after having used an 18” SuperJig for several years. I have 24 drawer boxes to dovetail. Sounds like I should plan on thoroughly reading and re-reading the instruction manual before I set it up and then expect some trial and error on the initial set up.

-- Earl "I'm a pessamist - generally that increases the chance that things will turn out better than expected"

View splintergroup's profile


3209 posts in 1830 days

#7 posted 12-10-2019 03:23 PM

I have a DR4 that I’ve used a few times with good results, but I’m definitely still a novice level user. I’m watching this thread for all the good tips. The addition of some grabby paper to the clamping surfaces is the first thing I’ll do, I recall things slipping slightly during test cuts and giving me grief.

View Gerald Thompson's profile

Gerald Thompson

1234 posts in 2842 days

#8 posted 12-10-2019 03:32 PM

Would poplar be considered hard enough for using for setup? Or should I use something such as red oak? I do not have any cut offs of other species.

-- Jerry

View Redoak49's profile


4355 posts in 2596 days

#9 posted 12-10-2019 03:43 PM

I think poplar would be better than pine. I find that each type of wood may need a slightly different set up to get the same fit. The router bit leaves a different surface roughness with different types of wood.

View Fred Hargis's profile

Fred Hargis

5929 posts in 3101 days

#10 posted 12-10-2019 05:03 PM

Poplar is almost always what I use to setup, though in all honesty most of my drawer boxes are also poplar (which is where most of my DT joints end up).

-- Our village hasn't lost it's idiot, he was elected to congress.

View LesB's profile


2315 posts in 4050 days

#11 posted 12-10-2019 06:34 PM

The jig does need patience to set up. The biggest problem as I diagnosed it was with the guide bushing. When I changed from the dove tail bit to the straight bit the guide bushing on the router base usually ended up in an ever so slightly different orientation relative to the guides on the jig (in other words it was not exactly centered on the router base) which caused the alignment of the tails and pins to be slightly off. I haven’t found a fool proof cure for this. ....Actually I have found a cure; I bought a PantoRouter which is much easier to set up and works great. Only draw back is it won’t do extra wide boards in just one set up like the Leigh.

-- Les B, Oregon

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