Leigh FMT PRO - Page 39

Frame Mortise & Tenon Jig User Guide
35
Chapter 5
MULTIPLE JOINTS
5-22 The maximum dimensions for quadruple joints are:
Tenon Workpiece
➀
: 3" x 5
1
⁄2"[70 x 140mm]
Tenon Size
➁
:
1
⁄2 x 2"[12 x 50mm]
Center Spacing
➂
: 1
1
⁄2 x 2
1
⁄2"[38 x 63mm].
2
3
3
1
1
2
5-23 Tenons Mark the four tenon and mortise centers to suit
your layout. Take care to leave a space between tenons
➀
at least
slightly greater than the tenon bit diameter
➁
.
1
1
2
5-24 Center (approximately)
➀
and clamp the tenon board on
the clamp plate and set the side stop fence. Note: If the tenon
board does not touch the underside of the table, extend the sight
to stop the board.
11
5-25 Extend the sight, release the table clamp and move the table
to sight the left hand front tenon
➀
.
Lock the table.
Move the right hand
LR
stop to its post and lock
➁
.
Move the back
FB
stop to its post and lock
➂
.
2
3
1
1
Quadruple Joints
5-20 Move the table back against its stop
➀
and lock. Rout the
rear mortise
➁
. Leave the table back.
2
1
5-21 Extend the sight, unclamp and move the mortise board left
so that the rear mortise of the pair at the right end of the piece
is centered under the sight
➀
and re-clamp. Mark the left hand
outrigger or set a stop
➁
adjacent to that end of the workpiece. Rout
first the rear mortise at this (right-hand) end, then move the table
and rout the front mortise. The outrigger marks or stops are now set
up for successive workpiece mortising.
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1
2