Leigh RTJ 400 Dovetail Jig

[Ronn W]

I will not make this a “how to“ review but will  limit my review to ease of quality, ease of set up, documentation etc.  Please note that this is my first dovetail jig.

I used my fence a a dust collector.

The basic difference between this jig and most others is that it is used on a router table.  You move the jig, not the router.  I had concerns that my home made router table, while pretty flat and very sturdy, would not be flat enough to give good results.  No problem.  If your table insert has a slight dish to it, no problem since the jig is long enough that it is supported on the table on either side of the insert.  This jig is about 24” long and can hold a 16” wide board.

First step for me was to watch the DVD.  The DVD is 75 minutes long. It starts, (Introduction thru chapter 6) with basic assembly and operation (along with the obligatory safety spiel).  This is followed by one chapter for each type of joint.  It is obvious that each chapter was produced separately since a lot of the setup and safety information is repeated in each chapter.  Use the fast forward button as you see fit.  The basic jig comes with only the larger dovetail and straight bits, so to make some of the smaller joints in the later chapters you need the ACJRT accessory kit which has several smaller straight and dovetail bits and a different adjustable bushing.

You are pretty much obligated to use Leigh bits (or second party bits made for Leigh jigs; Whiteside has some).  The larger jigs have a ½” shaft and the smaller bits have am 8mm shaft – The reducing collet comes with the accessory kit.  Also, the Leigh bits are longer than typical bits that you might be using because the bits need to project and additional 3/8” above the table top due to the thickness of the jig base.   Their bits are made in Taiwan with steel from Sweden.  The bits come with a dipped coating inside a plastic bag inside a plastic storage box.  The machining appears to be good quality but the carbide cut edge is significantly thinner than a Whiteside bit of the same diameter.

The aluminum base is solid aluminum CNC milled.  Finish is clean and edges are smooth.  The various clamps and stops are plastic but appear to be robust and not flimsy. Edges are smooth and nicely shaped.  Any bolts and nuts are steel – no plastic threads.  When you attach the jig body to the base in any of the many possible positions it is solid without any play or give.

The spacing of the pin guides on the base is ¾”.  This is not adjustable.  But by placing the body of the jig (the part that holds the wood) in different indexed positions you can space dovetails at ¾” o/c, or 3/8” o/c.  Box joints pins can be spaced at ¾”, 3/8”, 3/16” and 3/32”.  Again the smaller spacings required the accessory kit for the smaller bits and bushing.

You will need a typical stepped router base like the type used for Rockler or Wood river bushings (see pic) for the Leigh bushing. 

Assembly:  It took me about 30 minutes to put the few pieces together.  Should have been much less if I had read the instruction more carefully first. I can hear my wife saying, “I told you so. It must be a guy thing.”  I did have considerable trouble installing the sliding stops.  A square nut is slid into the track and the screws that hold the stops to the nut are about 1 thread too short to engage easily so I had a lot of trouble (about 10 minutes) getting the threads started.  Once in place the stops worked fine. I have to remember not too over-loosen the bolts when I have to slide the stop to a new position.

Routing a thru dovetail joint:  I set up the jig for a thru dovetail joint in ¾” pine.  During my first attempt I let he bit grab the piece and the board moved – Bad technique on my part.  Second attempt went great – see pic.  However I thought  the joint was a little loose so adjusted the bushing as directed.  Bingo. 

I should mention here that, according to the directions the width of the boards to be jointed with dovetails must fall within a certain range.  For example, if you want 3 dovetails the board must be 4 11/16 (+ ¾ bit dia, - ¼ bit dia)  I have not had a chance to explore what happens if you are outside this range.  I think it has to do with stop settings, etc.  I have a feeling that there is a work around.  I did talk to Leigh and they confirmed that you can make joints where you skip some dovetails to create joints where the dovetails are not all evenly spaced.  This is not covered in the manual.  So there is some exploratory play value to this jig.

Routing a box joint:  I set up the router to cut 3/8” pins in ¾” pine.  Setup took about 10 minutes reading the instructions.  If I knew what I was doing it would be less than 5 minutes.  It is very straight forward.  As always a test cut is recommended to check bit height and tightness.  See Pic.  Excuse the tear out on the pine.

Routing Half blind dovetail:  This is the easiest set and easiest cut of because both boards are router at the same time.  I made one test cut which was a little loose, adjust the bushing and BAM!  Dead on the nuts.  Note:  my 2 boards were not the same width.  Yes, you can do rabbetted half blind dovetails just as easily.

So I have used all of the bits that came with the jig.  There is a shallow learning curve.  If you don’t use it every day and tend to forget the details like I do, the set-up guide strips of sturdy paper that inset into the top of the jig are well done and very handy.

Conclusion:  At $359 it is a little costly and it does not have the flexibility of the D4R or Super 12” with adjustable spacing.  But the jig is well made, accurate as hell and easy to use. (No brain drain during set-up) The ACRTJ accessory kit with 9 more bits, an 8 mm collet adapter and an adjustable bushing sells for $159.  It would be great if they sold them both for about $375 but they don’t.  I like this jig.  I am going to get the accessory kit and I am going to have fun.

[wtnhighlander]

Great review, Ronn. Thanks for posting!

[treeslayer]

yep, thanks for posting Ronn, i have the D4R and like it a lot, the RTJ 400 looks like a good alternative.

[bglenden]

How long a board do you think you could handle? I'd guess it's good for drawers/boxes, but not case sides?

[ClassAct]

My FIL has one and I've had the pleasure of using it for an evening of playing around. It's pretty easy to use with decent instructions. Can't say much more than that because one data point does not a trend make.

[Ronn W]

4 hours ago, bglenden said:

How long a board do you think you could handle? I'd guess it's good for drawers/boxes, but not case sides?

Don't know exactly. The length is limited only by what you can comfortably work with (standing on end) without having it tip on you.  The base must be in firm contact with your router table at all times.  I will say that the handles that you hold when moving the jig during routing give you a pretty good full handed grip on each end of the jig.