A method for measuring brush wear in a motor of a saw includes generating, with a sensor connected to a brush in a motor of the saw, a first signal corresponding to a level of wear in the brush and identifying, with a controller, a level of wear for the brush with reference to the first signal. The method further includes generating, with the controller and a user interface device, an output requesting replacement of the brush in response to the identified level of wear exceeding a predetermined threshold.

A circular saw machine capable of suppressing a cutting-bending of a circular saw blade during cutting, and improving processing accuracy for a cutting surface of a workpiece, regardless of a size of a width of the workpiece. A circular saw machine has: a processing head capable of moving in a cutting direction and its opposite direction and having a circular saw blade capable of rotating; and a movable saw blade guide set provided to be movable in the cutting direction and the opposite direction on the processing head, for guiding to pinch a body part of the circular saw blade on a diameter direction inner side of a cutting region in the circular saw blade. The movable saw blade guide set is configured to move relatively with respect to the processing head in the opposite direction, in coordination with a movement in the cutting direction of said processing head.

A circular saw machine capable of suppressing a cutting-bending of a circular saw blade during cutting, and improving processing accuracy for a cutting surface of a workpiece, regardless of a size of a width of the workpiece. A circular saw machine has: a processing head capable of moving in a cutting direction and its opposite direction and having a circular saw blade capable of rotating; and a movable saw blade guide set provided to be movable in the cutting direction and the opposite direction on the processing head, for guiding to pinch a body part of the circular saw blade on a diameter direction inner side of a cutting region in the circular saw blade. The movable saw blade guide set is configured to move relatively with respect to the processing head in the opposite direction, in coordination with a movement in the cutting direction of said processing head.

A battery-powered hand-held machine tool, particularly a hand-held circular saw, includes an electric motor for rotational driving a tool arranged on the hand-held machine tool, particularly a saw blade, a front handle and a rear handle each in terms of an advancing direction of the hand-held machine tool, and a receiving recess for receiving a replaceable battery. The rear handle is mounted such that it can pivot out, preferably upwards, about a pivot axis such that when the rear handle is in a state of being pivoted out, the receiving recess for receiving or removing the replaceable battery is exposed and, when the rear handle is in a state of being pivoted in, the reception or removal of the replaceable battery into or out of the receiving recess is blocked.

A battery-powered hand-held machine tool, particularly a hand-held circular saw, includes an electric motor for rotational driving a tool arranged on the hand-held machine tool, particularly a saw blade, a front handle and a rear handle each in terms of an advancing direction of the hand-held machine tool, and a receiving recess for receiving a replaceable battery. The rear handle is mounted such that it can pivot out, preferably upwards, about a pivot axis such that when the rear handle is in a state of being pivoted out, the receiving recess for receiving or removing the replaceable battery is exposed and, when the rear handle is in a state of being pivoted in, the reception or removal of the replaceable battery into or out of the receiving recess is blocked.

A method of detecting kickback during operation of a saw includes identifying with a controller in a saw a measured rotational speed of a rotating blade in the saw with reference to signals from a rotational rate sensor, identifying with the controller an estimated rotational speed of the rotating blade in the saw with reference to the measured rotational speed, at least one previously measured rotational speed, and a measurement of a previous change in rotational speed of the rotating blade, identifying with the controller an estimated torque force for a drive shaft of a motor in the saw that rotates the blade with reference to the measured rotational speed, and activating with the controller a blade arrest mechanism in response to a difference between the measured rotational speed and the estimated rotational speed exceeding a first threshold and the estimated torque force exceeding a second threshold.

A method of detecting kickback during operation of a saw includes identifying with a controller in a saw a measured rotational speed of a rotating blade in the saw with reference to signals from a rotational rate sensor, identifying with the controller an estimated rotational speed of the rotating blade in the saw with reference to the measured rotational speed, at least one previously measured rotational speed, and a measurement of a previous change in rotational speed of the rotating blade, identifying with the controller an estimated torque force for a drive shaft of a motor in the saw that rotates the blade with reference to the measured rotational speed, and activating with the controller a blade arrest mechanism in response to a difference between the measured rotational speed and the estimated rotational speed exceeding a first threshold and the estimated torque force exceeding a second threshold.

A method for detection of proximity between an object and an implement in a table saw includes operating a motor in the table saw to move the implement, generating, with a capacitive sensor formed in a throat plate around the implement in the table saw, a capacitance signal during operation of the motor, identifying, with a controller operatively connected to the capacitive sensor, an object in proximity to the capacitive sensor in response to a change in a level of capacitance in the capacitance signal, and deactivating, with the controller, the motor in the table saw in response to the change in the capacitance signal indicating a capacitance level that exceeds a predetermined threshold corresponding to a body part of an operator.

A method for detection of proximity between an object and an implement in a table saw includes operating a motor in the table saw to move the implement, generating, with a capacitive sensor formed in a throat plate around the implement in the table saw, a capacitance signal during operation of the motor, identifying, with a controller operatively connected to the capacitive sensor, an object in proximity to the capacitive sensor in response to a change in a level of capacitance in the capacitance signal, and deactivating, with the controller, the motor in the table saw in response to the change in the capacitance signal indicating a capacitance level that exceeds a predetermined threshold corresponding to a body part of an operator.

A circular saw including a housing, a motor disposed within the housing, a spindle operable to be rotated by the motor, and a saw blade supported by the spindle for co-rotation therewith. The saw blade includes a hub portion located at a center of the saw blade and a blade portion extending therefrom. The hub portion is offset from the blade portion to define a pocket between the blade portion and the hub portion. The circular saw also includes a fastener securing the saw blade to the spindle. The fastener is at least partially recessed within the pocket.