Sliding Dovetail Question

[skipclemmons]

In his highly useful MFT manual, Mr. Work spends a great deal of time on mirroring and cutting the female slot, but on the male side he simply says:

"All that is left now is to cut the male dove-
tails on the various ends of the respective
pieces."

Then we are on to finishing and assembly.

The male dovetail sounds like more of a project than the description implies.  Is there a Festool-only solution for the male-dovetail process or do I need a router table?  What do you sliding dovetail guys do?

Appreciate the help.

 

 

[Dave Rudy]

Is there a Festool-only solution for the male-dovetail process or do I need a router table?  What do you sliding dovetail guys do?

Appreciate the help.

Appendix A to Jerry's  MFS manual (available on the Festool site under woodworking tips) is all about his male sliding dovetail jig.  It is basically a horizontal router table which uses the MFT.  You can also buy horizontal router tables from Hawk Industries, MLCS and Woodhaven.  Pat Warner also has a sliding dovetail/tenon-maker jig available for sale on his website and has a neat video available to subscribers on finewoodworking.com showing the use of the jig.  I am an utter novice at sliding dovetails but would love to master this joint so I've been doing some research which may save you some steps.  There are also some guys here who are as far from novice as can be -- hopefully they will chime in and give us both some guidance.

Dave

 

[skipclemmons]

Found it.  Thanks.

I knew there was more to it!   The horizontal router jig is a nice piece of work. 

I noted the disclaimer at the end.  Wonder if that jig could get UL approval and Festool commercialize it?

sc

 

[Jerry Work]

Male sliding dovetails can easily be cut on any router table so long as you have a 90 degree push fixture.  The work piece has to be held upright both relative to the face and to the edge so a high fence and good push fixtue like the Jessem unit make it much easier.  The bit should be burried inside the fence with just the tip showing.  Make a cut pass on both sides and check the fit.  Move the fence by half the error in the fit.  A couple of tries will get you spot on.  Be sure to set the cut depth to be the same as you used on the female DT slot.  Backing up a bit, the fist step is to make sure your work pieces are straight and the ends cut exactly at 90 degrees.  Then use the router table as described above and you will get a good fit most of the time.  For larger work pieces the horizontal router jig is really nice but if you are careful and use feather boards to keep the work piece tight against the fence (so it is kept upright and not tipping to and fro) you can make even long male dovetails in even very large work pieces if you can't or won't take the time to build the horizontal jig for yourself.  Hope this helps.

Jerry

 

[CharlesWilson]

Thanks for the clarification, Jerry. This is the method I was going to try, and if it didn't work out well, I would then construct the horizontal setup you described in the MFS appendix.

 

[enderw88]

Just as a point of clarification for other people searching for the appendix A mentioned above. It is at the end of the document called "Advanced cutting and routing techniques using the MFS multi routing template by Jerry Work".  It is not a separate document.

 

[greg mann]

Jerry,

There have been several articles recently waxing poetic about tapered sliding dovetails. You don't seem to be a proponent. Would you care to comment?

 

[Tinker]

So far, I have not tried making sliding DT's with my Festool toys.  I have, however made them with my WoodRat.  That has two guides, on for each side of the guide plate which the router is attached to.  those can be set at a very slight angle from parallel so the DT (both male & female can be tapered.  With that system, the widest (longest) you can make the DT's is about 8".  Before getting the Rat, I had made a jig to slide my PC router in.  I could taper the female side of the joint, but did not even try tapering the male side. 

The tails seemed to lock in place either way.  The trick seemed to be to make the joints match up so you required some pressure to make them tight and a tap of the hammer on the front if you wanted to losen. 

I made a couple of bookshelves with sliding DT's that could be knocked apart.  The first with the DT's straight, I eventually glued.  The other other I made for my daughter when she was in a moving from condo to condo situation.  That set of shelves I tapered the DT's so they would be real strong when assembled, but a gentle tap on the front of the shelves and the whole assembly could be easilly pulled apart and the pieces, shelves, sides and all, could be packed into an easilly handled bundle that could be transported in her car.

Tinker

 

[Loren Woirhaye]

I wouldn't wish to dissuade anyone from attempting the
tricky setups and fine tuning of sliding dovetails.

BUT:

the "half sliding dovetail" is a heck of a lot easier to make
and fit, especially in wider boards.  The reason is you can
fit the joint with a handplane and a piece of chalk. 

How: cut the joint slight over-wide and plane the back of
the board to fit.

If you make a full sliding dovetail in a wide board make sure
the board is very flat and consistent in width first... because
little variations can cause hair pulling as you try to hunt down
the too-thick sections with a chisel  (a handplane won't fit
in that dovetailed angle).

 

[Dave Ronyak]

Loren,

Help me understand your proposed variation on a sliding dovetail.  When the joint is viewed in section, is one wall simply flat and parallel to the top/bottom of the board and the other inclined like a typical dovetail? 

Dave R.

 

[Loren Woirhaye]

Yeah, right.

If you are just doing a sliding dovetail 3" deep for say the dividers
in a carcase for a chest of drawers... and you like the way it
looks... then by all means make the double-sided dovetail..

If you are going wider though you'll find the joint progressively
fussier to fit as you get wider.  Its actually a good idea to cut the joint
so its snug at both ends and loose in the middle... otherwise you'll
have a helluva time getting it together and apart when you
trial fit the parts.

A half sliding dovetail has  the angled part on just one side.  It
still has tremendous strength over a dado (or a rabbet, for that
matter, like in a drawer box), and it won't break unless you
throw the piece off a building.

A sliding dovetail is like a tenon in some ways.  Its got a shoulder
there that resists racking so it can help keep things square. 

Excavate the groove with a flat bottom cutter of some kind,
widen it with your dovetail bit,  then cut the male part OVERSIZED on
the router table or with an edge guide if the board is too long
or heavy. You just cut the joint on one face of the board...
so you just have one shoulder there instead of two.   

Then you break out the handplane and work down the back
of the board till the joint fits.