I am making a set of drawers with half blind dovetails using my Rockler
Dovetail jig. This jig is incredibly difficult to set up to get perfect
dovetails. OTOH I don't make a ton of drawers so maybe I should just suck it
up. I would value the opinions of members of this group as always.
That's probably because most of those jigs are in fact very difficult to
setup. The key problem is the height of the bit. Or the offset from
side to side.
The offset from side to side is easy to work with. Just make the sides a
little larger and plane or saw down accurately after they are joined.
Put a knife mark from the front to the sides and cut to that mark.
I handcut dovetails rather than deal with it.
But if I had production work to do I would not hesitate to spend the
time setting up a jig. Half blinds are much harder both with a jig and
by hand than through cut DTs.
I often have to make a "ton of drawers", have both the Leigh DR4 and the
Akeda 16DC, and both are equally finicky, although the Akeda a bit less
so than the Leigh.
I have learned to deal with the fact that router based dovetail jigs are
problematic at best, but for productions runs, they are absolutely
necessary for a small shop.
And because of all the things that have to be just right I have really
started to like using box joints over the DT's. Especially with the
Incra iBox box joint jig on the TS, joints are a breeze compared to the
Way back in 1980 I bought a Craftsman DT jig. It really worked quite
well and IIRC had darn few instructions but I do recall it mentioning to
start on scraps and start with a particular bit depth and adjust from
that point. IIRC I paid about $40 for the jig.
The point here is that Blind dovetails are incredibly simple. BUT you
have to have every thing set up precisely and the bit cutting depth of
both sides of the mating pieces is the same.
Be certain that you are using a good quality and exact size guide
bushing that the jig calls for. If you can center the base/bushing to
the bit, do that before making any cuts. This can save you a lot of
If not remember to never clock or turn the router during the cutting
operation. If the bit is not perfectly centered in the guide bushing
and you even slightly rotate the router during the cutting operation
some of the pins and tails will be a bit larger and or smaller than
others. When you are rotating the router and the bit is not centered in
the guide bushing you are cutting off center and rotating the router
will change the cutting location even more.
Typically you mount a vertical board in the front of the jig a bit lower
than the top of the pin board. You set the end of the pin board up
against the back side of that vertical board and then lower the template
down on to the top pin board.
The template must set flat on top of the pin board, no exceptions. This
mandates that the board also be flat.
Next, the vertical tail board must be flushed up to the bottom of the
template. Be careful not to push up too much and bow the template.
Remember the template must sit flat on top of the pin board.
Once you have this all correctly in place you begin your trial cuts.
Make your cuts and remove the boards.
Is the fit too tight? Raise the bit a touch, cut shallower.
Is the fit too lose? Lower the bit a touch, cut deeper.
Does one end fit differently than the other end of the joint? Your wood
and jig set up is wrong.
Get new scraps and test again. DO NOT reuse the same ends that were
Each DT bit tends to have it's own sweet spot as to how deep it should
be used at. When you are finished with the operation you can either
leave that bit in the router, ;~) or measure the height setting before
removing that bit so that the trial by error fit will be less trouble
the next time.
Most people don't have a dedicated router to leave a DT bit in. Unless
you are a production shop. I do leave a 1/8 inch round over in one of my
But like Leon said you should mark it. The best way is to rout a new
board as a depth gauge, just put it in the jig.
Then mark this board as the gospel.
But you still need to work out the offsets.
Still don't know which issue is your problem, the router bit heights or
I have made a depth gauge just as you mentioned above so that getting the
router bit to the right depth is fairly easy. It is the adjustments to the
jig which are really time consuming and frustrating. I just put up a reply
to Leon to give you one example.
Everything you say matches my experience with the Rockler Dovetail jig. The
problem is that making adjustments can be a total pain in the rear. For
example, there is a fence that determines how far your router will go in to
the grooves or sockets on the board that is lying flat. Each end of the
fence has to be tightened down separately with a screw and handle and it is
a BEAR to get the fence to be exactly parallel to the template. I need many
measurements with a digital caliper to get it exact.
I guess the message for me is "suck it up. The setup process is a pain in
I think I see the jig on Rockler's web site. That jig with the fence
introduces yet another adjustment. If the base on your router is not
round and or centered too, clocking it will cause you to cut too deep or
shallow too. Typically the bottoms of the fingers on the template
dictate the depth of cut front to back, that is.
Time to talk to "Routerman", AKA: Pat Barber.
He offers a router base plate that allows you to center the bit and
bushing concentrically which will make life a lot easier.
Saw your other post.
I built some drawers using the Jet jig and had to be very careful
to maintain registration since the guide bushing was not concentric
Still had other problems which I was able to resolve to produce
As I remember, glad I don't have to making a living producing
Clearly the source of errors consists of router end play of the router
shaft, variation of stock thickness, the profile of the cutter which
depth of cut and the concentric registration between bit and guide
While your plate doesn't solve all the sources of error,
seems like it should make life a lot easier, if you insure concentric
registration between bit and bushing.
What am I missing?
Easy enough there are many centering bits on the market.
Do not buy the woodline centering, it's useless. The pc collar that came
with it did not fit any of my routers it was way undersized. And it
requires you to use 1/4" collet. Others use 1/2 and 1/4 flip style shafts.
Welcome to the "pain-in-the-ass" club. I think I currently own "about"
3 dovetail jigs.
I bought a PC "el-cheapo" about 15 years ago.... poor - fair results.
I bought a PC Omnijig about 10 years ago. Same as above.
My wife bought me a PC 4210 jig about 5 years ago... more of the same.
That subject has been beat to death here for years with varying results.
My current plan is to spend a month or two and learn how to make a
"perfect" locking rabbet and sell all those dovetail jigs at a flea
Except for the most treasured projects (those I consider may gain
heirloom status in my immediate family some day), I have taken to using
locking rabbet joints for drawers when 'eating my own dog food', as well
as for those projects where the client doesn't want to spring for
I make them on the table saw, and (like any other project), as long as
your stock is consistently flat and square, they are quite useable
joints that can be made and assembled very quickly.
AAMOF, I went to the trouble of making a short SketchUp video and put it
on youtube, more to refresh my own memory on the steps as I get older
than for any other reason.
Yep...I agree and all of my DT jigs were at least consistent in
producing the same poor joints.
They are one of the few tools I have bought in the last 20 years
that I was very disappointed in.
No more fighting....I'll switch.
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