wrote in message
...
On Thu, 15 Oct 2009 08:24:03 -0500, "Leon"
wrote:

tenons would all come together precisely. With 8 tenons in each shelf I
could afford to leave out a tenon or 2 in necessary, I was even prepared
to
sand and make a tenon a bit thinner so that it would fit into a
misaligned
hole.

I seem to remember maybe incorrectly, when I was watching an online
example of Domino construction, that the Domino had the ability to cut
some slots marginally wider than the tenons for alignment purposes.

Glad you brought that up. ;~) I meant to mention it earlier. Yes the
Domino has a precise width setting, a setting 3~4mm wider, and a setting
5-7mm wider. Don't quote me on those measurements however.


Is that something you considered doing?

That is what I do 100% of the time when using more than 1 domino and
alignment is critical. What, what did he just say?
May I step up to the podium?
With more than a couple of years of woodworking under my belt it is my
belief that a tenon does not have to precisely fill 100% of the hole to
deliver 90% of its strength. If you feel that you need 100% of the strength
of the tenon, you should probably be using a larger tenon because if you ask
101% strength from the joint, it is going to fail anyway.

Now a little bit about the Domino. I am not positive how the new style
works with the indexing tabs but on the first style the Domino used 2 spring
loaded collapsing steel dowels. One, the one on the right side as you hold
the tool pointing away from you is fixed. The left dowel is mounted in an
eccentric cylinder that can be turned/adjusted to bring the indexing pin
closer or farther away from the center of the cutter path. Both indexing
pins being "exactly" the same distance from the center of the cutter
path/cut helps insure that both halves of the joint index exactly where you
would expect. If the adjustable one is not in "perfect" sinc with the
opposite side pin the edges of the pieces being brought together by the
domino tenon will be slightly misaligned if you are using the perfect fit
cutter setting. Basically for one piece you use the right indexing pin,
for the other side you use the opposite indexing pin.

WHAT IN WOODWORKING IS PERFECT?

I personally do not believe the "perfect" alignment of the indexing pin is
something that should be trusted. Remember, the narrowest of the cutting
widths is precisely the width of the tenon. I mainly use the 5mm thick
domino tenons and when used with the exact sized hole I have to drive them
in with a small hammer or use the clamps to push them in. There is none of
this push them in with your thumb and there is certainly not any pulling
them out with out a pair of pliers with out damaging the tenon dry fitted.
Given that comment the tenons all fit, none in the last 2.5 years have not
fit, just be advised they fit precisely. The larger tenons do however fit
a "bit" more loosely but are still pretty snug. So when dry fitting 5mm
tenons you typically do not need clamps to hold every thing together and a
small rubber hammer or the like will be needed to sperate the parts. On my
tower project the "DRY FIT" tenons on the 4 shelves held all side panels
well enough that I was able to take the unit down from the TS top and set
them up right with absolutely no fear of them coming apart. Once you add
glue, that is a done deal, period.

BECAUSE the tenons on the narrowest cutter setting fit "precisely" every
additional tenon and mortise on both sides of the joint have to be
"PERFECTLY ALIGNED". May I ask again, What in woodworking is perfect? If
the wood swells over night some thing is not going to be perfectly aligned
any more. To solve this dilemma Festool lets you adjust the additional
mortises to be slightly wider so that the after the first perfectly fitting
tenon is cut you don't have to worry about getting the remainder of the
mortises down the edge of the board "PERFECTLY" spaced on both sides. If
you try to use 2 tenons in exact sized mortises and the spacing is not
"perfect", the joint probably will not close.

On the tower face frames I used 5mm tenons for the rails and stiles. If you
will recall I index spaced the 4 common shelf rails from the bottom rail.
It was important that the bottom rail remain stationary so that I could have
a solid stationary point to begin using my indexing rods for repeated
accurate spacing of the remainder 3 shelf rails. I use the exact fit cut
for the bottom rail mortise. For the remaining domino mortises I used the
next width cutting setting. This allowed me to wiggle the rails to the
perfect location using the indexing/spacer rods.

So normally I do not use the exact mortise cutting width unless I want the
piece being attached to be stationary during glue up and I only cut one
exact size for that purpose. The Domino can also be indexed visually like
a biscuit cutter is indexed. Put the two pieced together, draw across the
joint line where you want a tenon and use the visual indexing gauge on the
domino to cut at those points. It is important that you use the wider
cutting setting at those points as the Domino might wiggle to one side or
the other when cutting the mortise, but that is OK, absolutely not a problem
as long as you use one of the wider cutting settings.

With the wings accessory attached, I forget their exact correct name, you
also can use their adjustable indexing pins indexed in side of previously
cut mortises if you want to cut all the mortised evenly spaced with out
repeated measuring.


Now you did not ask but, up and down alignment is just as precise. One of
my first get to know the Domino test cuts in 3/4" thick MDF produced a joint
line that was hardly viable and one you could not feel. I can only caution
you to always use the fence to index. If you use the bottom of the Domino
to index the up and down alignment may not be desirable for a number of
reasons. If the wood is slightly warped, twisted, or bowed it will not set
flat on the surface it is setting on. If there is dust or debris under the
wood it will not set flat on the surface it is setting on. Additionally the
Domino may not set flat on the work surface if there is dust or debris
present. So I again advise to always use the fence to index from. This
should also be the practice with biscuit cutters. If the stock is too thin
and the Domino sets on the work surface, clamp the piece so that the end or
edge is hanging off the end of the work surface. This will allow the fence
to index against the top side of the piece.


AND FIY and this is a strange oddity that you just have to get used to.
When you use the CT22 or probably any other shop vac with the Domino, the
Domino remains dust free. After a few thousand mortises my Domino still
looks brand new. Can you imagine how accurate a tool will remain and how
much longer it will last when no dust ever collects from use? The sanders
look the same way.

Any more questions? LOL



















Or, let me hazard a guess
that it's usually not necessary to use that function because the
Domino is capable of pretty precise cutting and alignment adjustment
is usually not necessary?