Cutting Base Molding; Cutting Crown Molding - Bosch GCM12SD Operating/Safety Instructions Manual

2610051827 GCM12SD 08-18.qxp_GCM12SD 9/19/18 2:52 PM Page 50
• Base molding can be cut vertical against fence or flat on the table. The maximum size that can
be vertical on the fence is 6-3/4", flat on table is 13-1/2".
• Follow the table for helpful hints on cutting base molding for corners that have 90° angles.
• Cutting base molding can be done either as a chop cut or a slide cut depending on the size of
the workpiece.
LOCATION OF
MOLDING ON SAW
Bevel Angle
Molding piece being cut
Inside
corner of wall
Outside
corner of wall
Crown molding cuts must be positioned properly
to fit exactly.
There are two ways to cut crown molding: flat
on table or angled to table and fence.
Crown molding's "spring angle" is the angle be-
tween the back of the molding and the bottom
flat surface that fits against the wall.
This miter saw has special miter detents at
31.6° and bevel detents at 33.9°. These
detents allow you to easily position most crown
molding flat on the table and make precise cuts
for 90° corners. NOTE: These detents cannot be
used with 45° crown molding. These detents
are only for use with crown molding that has a
38° "spring angle."
50
Saw Operations

Cutting Base Molding

BASE MOLDING CUTTING INSTRUCTIONS
Molding in Vertical Position:
Back of molding is against
To left of
corner
Miter Angle Left at 45º
Position
Bottom
of molding
against table
on saw
Keep left
Finished side
side of cut
Miter Angle Right at 45º
Position
Bottom
of molding
against table
on saw
Keep left
Finished side
side of cut

Cutting Crown Molding

the fence
Bevel = 0º
To right of
corner
Right at 45º
Bottom Top against
against table
Keep right
side of cut
Left at 45º
Bottom
against table against fence
Keep right
side of cut
See also page 53 for miter and bevel angle
charts for cutting crown molding that has
38° and 45° spring angles. Each chart lists the
exact miter and bevel settings required for a
wide range of corner angles.
Even though these angles are standards, most
rooms do not have angles of exactly 90°; there-
fore, you will need to fine-tune your settings.
The optional Bosch GAM 220 MF and GAM 270
MFL Digital Anglefinder/Protractors measure
spring angles and corner angles, then automat-
ically determine the exact miter and bevel set-
tings necessary to make each crown molding
cut fit perfectly.
Molding in Horizontal
Position: Back of molding
is flat on the table
Bevel = 45º
To left of To right of
corner corner
0º 0º
Bottom
fence against fence
Keep left Keep left
side of cut side of cut
0º 0º
Bottom Top against
fence
Keep right Keep right
side of cut side of cut