Doug Miller wrote:

snip


Ahh, now I see the cause of the confusion -- we are picturing two entirely
different types of chairs. Your picture is of a chair with non-vertical legs,
having the same horizontal separation between the left and right sides at both
front and rear. *My* picture is of a chair with *vertical* legs, having a
wider horizontal separation between the front legs and the rear legs, e.g.

Side View Top View

| +-------+ back
| / \
| / \
| / \
+---------+ +---------------+ front
| |
| |
| |
| |

I understand clearly how the tilting-head mortiser can cut the angled mortises
needed for your picture of a chair. But how on earth can it cut the angled
mortises needed in *my* picture, unless the fence and leg can be pivoted 90
degrees?

--
Doug Miller (alphageek at milmac dot com)


So many ways to use M&T joinery and so many ways to do them. If you
combine
the chair example I did with the one you did things really get harry
and
things get really interesting. A horizontal boring/mortiser machine
can
do a bit more than either a fixed or tilting head chisel and bit
mortiser.
Add the jig described by the url below and you can cut mortises at
almost
any angle or compound angle. A guy in the Yahoo Robland X31 group
came
up with this slick jig. With its two T-slots you can cut just about
any angle on any axis, assuming your mortiser has the throw and the
bit long enough.

www.wood-workers.com/users/charlieb/!RaysMortiser1/RaysJIG1.html

The horizontal boring/mortiser is the fifth function on the Robland
X31.
The pictures on the lower half of the following page shws the XYZ
table and the bit in the chuck on the end of the joiner/jointer -
planer cutter head.

www.wood-workers.com/users/charlieb/X31pg3.html

Between roof rafters and chairs the old high school trig class
finally starts coming in handy. Sometimes I even use the
analytical geometry I learned in college. Now calculas and
differntial equations ...

Fun and intersting this woodworking thing.

charlie b