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charlieb charlieb is offline
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Default Festool DOMINO - doubling mortises in 2x4s

Power was on and off yesterday eve/night while I was trying
to respond to a question about "doubling" mortises on a 2x4.
I think it was "Rick"" that wondered how you could do this

+------------+
| +-+ +-+ |
| | | | | |
| +-+ +-+ |
| |
+------------+
on a 2x4 since the "presets" on the DOMINO only allow for up to
20mm from reference face to mortise centerline.

Well a buddy, with no prior experience with the DOMINO just
did this - on all the mitered corners of a 2x4 gate - 5'6" wide
by 7' tall.

+------------+"inside" obtuse angle of miter
| +-+ +-+ |
| | | | | |
| +-+ +-+ |
| | "inside" mortise 100mm from "knife edge"
| +-+ +-+ | "outside mortise referenced of 100mm mortise
| | | | | |
| +-+ +-+ |
| |
+------------+ "outside" knife edge end of miter

He used the 10mm "bit", "22" setting on the center on stock width
preset (center of resulting mortise is 11mm off either rerence face)
"outrigger pins set at 100 mm from mortise long axis center line.

Total time - with no prior experience - from first cut to last cut
*8th mortise) on one part - with mitered ends- was 2 minutes
22 seconds, including clamping and unclamping the part to flip it
over to use the other reference face for the second pair of mortises.
8 sets if 4 mortises cut and only two needed tweeking. The
tweeking was required because two of the part - green pressure
treated 2x4s were slightly bowed so the "knife edge" of their
mortises weren't square to the face of the boards. Because the
DOMINO was referencing off that "knife edge" the resulting mortises
were off by maybe 1/32nd of an inch - enough to make the joint
not line up. A pass or two with a file on the knife edge and 30
seconds
to recut the erroneous mortises and things fit.

Did I mention that the parts were 7' and 5'6" long? Imagine doing
the same mortises with even the Leigh FMT or MultiRouter - mortises
in end grain, on a mitered face - of a 7 foot long part.

I guess I gave the impression that the DOMINO could ONLY USE
the "presets". Actually, the fence range is 5mm to 30mm from
fence to mortise centerline using the provided scale on the DOMINO
So, as long as your part is thicker than 2.362" (2x30mm/25.4mm/inch)
you can center the mortise on stock anywhere from .394" to 2.362"

Regarding doing a pair of mortises, one centered on a 2" leg and the
other centered on a 1" apron - no big deal. Use the fence to mortise
centerline scale and set it between 25 and 26mm for the mortise
centered on the 2" leg and between 12 and 13mm for the 1" apron.

The DOMINO is an elegantly simple tool once you understand the
parameters you can use, what they do and how to do it. The
metric conversion to the more familiar imperial system muddles
the the water a bit and my shortcomings in communicating what
makes the DOMINO such a significant addition to the wodworking
tools and machines arsenal shouldn't muddle the waters further.

charlie b