Jet Tools JMS-12SCMS manual Cutting Base Molding, Crown Molding, Bevel/Miter Settings, Type of Cut

Cutting Base Molding

Base moldings and many other moldings can be cut on a compound miter saw. The setup of the saw depends on molding characteristics and application. Perform practice cuts on scrap material to achieve best results:

1.Always make sure moldings rest firmly against fence and table. Use hold-down, crown molding vise or C-clamps, whenever possible, and place tape on the area being clamped to avoid marks.

2.Reduce splintering by taping the cut area prior to making the cut. Mark the cut line directly on the tape.

3.Splintering typically happens due to an incorrect blade application and thinness of the material.

Note: Always perform a dry run cut so you can determine if the operation being attempted is possible before power is applied to the saw.

Crown Molding

Your compound miter saw is suited for the difficult task of cutting crown molding. To fit properly, crown molding must be compound-mitered with extreme accuracy. The two surfaces on a piece of crown molding that fit flat against the ceiling and wall are at angles that, when added together, equal exactly 90°.

Most crown molding has a top rear angle (the section that fits flat against the ceiling) of 52°and a bottom rear angle (the section that fits flat against the wall) of 38°.

In order to accurately cut crown molding for a 90° inside or outside corner, lay the molding with its broad back surface flat on the saw table.

When setting the bevel and miter angles for compound miters, remember that the settings are interdependent; changing one changes the other, as well.

Bevel/Miter Settings

Settings for standard crown molding lying flat on compound miter saw table.

Note: The chart below references a compound cut for crown molding only when the angle between the walls equals 90°.

		Bevel	Miter
Type of Cut	Key	Setting	Setting	Procedure
Inside corner – Left	IL	33.9°	31.6°	1.	Position top of molding against fence.
Side			Right	2.	Miter table set at RIGHT 31.6°.
				3.	LEFT side is finished piece.
Inside corner –	IR	33.9°	31.6° Left	1.	Position bottom of molding against fence.
Right Side				2.	Miter table set at LEFT 31.6°.
				3.	LEFT side is finished piece.
Outside corner –	OL	33.9°	31.6° Left	1.	Position bottom of molding against fence.
Left Side				2.	Miter table set at LEFT 31.6°.
				3.	RIGHT side is finished piece.
Outside corner –	OR	33.9°	31.6°	1.	Position top of molding against fence.
Right Side			Right	2.	Miter table set at RIGHT 31.6°.
				3.	RIGHT side is finished piece

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