A baler for forming crop material into a bale, said baler comprising: a chassis presenting a baling chamber in which the bale is formed; and a bale binding mechanism configured to wrap twine around the bale, said bale binding mechanism including- a baling needle shiftable relative to the baling chamber, with the baling needle being shiftable to advance twine along an end of the bale, a drive shaft supported by the chassis to power the baling needle, a clutch shiftable between an engaged condition in which the clutch drivingly interconnects the drive shaft and the baling needle, and a disengaged condition in which the clutch prevents the drive shaft from driving the baling needle, and a trip mechanism including a trip cam, a drive wheel, and a lockout device, said trip cam being shiftable between a trip condition associated with engagement of the clutch and a metering condition associated with disengagement of the clutch; said drive wheel being operable to shift the trip cam when in the metering condition, said trip cam being shiftable from the metering condition to the trip condition to engage the clutch when the bale is formed to a desired size, said lockout device removably engaging the trip cam to restrict the trip cam from shifting into the trip condition said trip cam presenting a cam opening that removably receives the lockout device for engagement therewith, characterised by said trip cam presenting a driven surface extending along the cam opening, said driven surface being engaged by the drive wheel in the metering condition, and said drive wheel being disengaged from the driven surface when the trip cam is in the trip condition. a chassis presenting a baling chamber in which the bale is formed; and a bale binding mechanism configured to wrap twine around the bale, said bale binding mechanism including- a baling needle shiftable relative to the baling chamber, with the baling needle being shiftable to advance twine along an end of the bale, a drive shaft supported by the chassis to power the baling needle, a clutch shiftable between an engaged condition in which the clutch drivingly interconnects the drive shaft and the baling needle, and a disengaged condition in which the clutch prevents the drive shaft from driving the baling needle, and a trip mechanism including a trip cam, a drive wheel, and a lockout device, said trip cam being shiftable between a trip condition associated with engagement of the clutch and a metering condition associated with disengagement of the clutch; said drive wheel being operable to shift the trip cam when in the metering condition, said trip cam being shiftable from the metering condition to the trip condition to engage the clutch when the bale is formed to a desired size, said lockout device removably engaging the trip cam to restrict the trip cam from shifting into the trip condition said trip cam presenting a cam opening that removably receives the lockout device for engagement therewith, characterised by said trip cam presenting a driven surface extending along the cam opening, binding mechanism including- a baling needle shiftable relative to the baling chamber, with the baling needle being shiftable to advance twine along an end of the bale, a drive shaft supported by the chassis to power the baling needle, a clutch shiftable between an engaged condition in which the clutch drivingly interconnects the drive shaft and the baling needle, and a disengaged condition in which the clutch prevents the drive shaft from driving the baling needle, and a trip mechanism including a trip cam, a drive wheel, and a lockout device, said trip cam being shiftable between a trip condition associated with engagement of the clutch and a metering condition associated with disengagement of the clutch; said drive wheel being operable to shift the trip cam when in the metering condition, said trip cam being shiftable from the metering condition to the trip condition to engage the clutch when the bale is formed to a desired size, said lockout device removably engaging the trip cam to restrict the trip cam from shifting into the trip condition said trip cam presenting a cam opening that removably receives the lockout device for engagement therewith, characterised by said trip cam presenting a driven surface extending along the cam opening, said driven surface being engaged by the drive wheel in the metering condition, and said drive wheel being disengaged from the driven surface when the trip cam is in the trip condition.