Leigh FMT PRO - Page 41

Frame Mortise & Tenon Jig User Guide
37
Chapter 5
MULTIPLE JOINTS
5-34 Because of safety considerations it is only practical to rout
triple joints with
3
⁄8 bits and guides or smaller.
Maximum dimensions for triple joints are:
Tenon Workpiece
➀
: 1
3
⁄4 x 5
1
⁄2"[44 x 140mm]
Tenon Size
➁
:
3
⁄8 x 2"[10 x 50mm]
Center Spacing
➂
:
7
⁄8 x 2
1
⁄2"[22 x 63mm].
1
2
3
3
1
2
5-35 Mark the three tenon and mortise centers, taking care
to leave a space between tenons at least slightly greater than the
tenon bit diameter
➀
.
1
1
5-36 Tenons Center (approximately) and clamp the tenon
workpiece on the clamp plate
➀
and set the side-stop fence.
11
5-37 Extend the sight, release the table clamp and sight the
front tenon of the pair
➀
. Lock the table, move the right hand
LR
limit stop to the post and lock
➁
. Move the back
FB
limit stop to the post and lock
➂
.
2
3
1
1
Triple Joints
5-32 Move the table to the rear right against the stops and lock
➀
.
Move the “guard” to the front-left
➁
. Rout the rear-right tenon
➂
.
Rout all other tenon ends required. Leave the table to the rear-right.
1
1
1
2
3
5-33 Mortises Extend the sight, position and clamp the mortise
board so that the rear right mortise is centered under the sight
➀
.
Either mark an outrigger or set a stop-block for successive mortise
boards
➁
. Rout all four mortises in their respective positions
➂
.
Note: The FMT Pro vacuum port may prove ineffective on wide
mortise pieces, particularly on the front mortises.
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2
3