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2. Inherent Drawbacks of Cordless
Driver Drills Requiring
Particular Attention during Sales Promotion
The cordless driver drill offers many advantages; it can be used in places where no power source is
available, the absence of a cord allows easy use, etc. However, any cordless tool has certain inherent
drawbacks. Salespersons must be thoroughly familiar with these drawbacks in order to properly advise the
customer in the most efficient use of the tool.
A. Suggestions and precautions on efficient use of the tool
(1) Use the cordless
driver drill for comparatively light work.
The motor output of battery driven cordless driver drills is rather low compared with conventional electric
power tools. Accordingly, they are not suitable for the continuous drilling of many holes in succession, or
for drilling into particularly hard material that imposes a heavy load. Salespersons should recommend
conventional electric power tools for such heavy work.
(2) Large-diameter holes should be drilled at low speed.
Instruct the customer that drilling large-diameter holes or performing other work that requires
particularly strong torque should be done at low speed. Because there is less torque at high speed,
attempting such work at high speed will not improve working efficiency.
(3) Do not insert a foreign object into body vent holes.
The body of this tool has vent holes for improved cooling efficiency. As a fan is built into the motor, a
foreign object inserted through a vent hole may cause failure. Please instruct customers to never insert
a foreign object into the vent holes.
(4) Use at thrust of 100 to 150 N (10 to 15 kgf, 22 to 23 lbs.)
The drilling speed of this unit does not accelerate even if the tool is pressed strongly against the
workpiece as when using a typical AC driver drill. Such operation will damage the drill bit, resulting in
not only poor working efficiency but also motor burnout.
(5) Avoid “locking” of the motor
Locking of the motor will generate an overload current that could result in motor burnout and/or rapid
battery deterioration. Salespersons should advise the customer to immediately release the switch and
stop operation if the motor becomes locked. (A jammed drill bit can be disengaged from the workpiece
material by setting the switch to reverse rotation, or by manually turning the main body of the tool.)
(6) Variation in amount of work possible per charge
Although the nominal chargeable capacity of the storage batteries used with the Models DS 14DSFL and
DS 18DSFL is 1.5 Ah, the actual capacity may vary within 10% of that value depending on ambient
temperature during use and charging, and the number of times the batteries have been recharged. It
should be noted that other factors that may affect the amount of work possible per charge are the
working conditions (e.g., ambient temperature, type and moisture content of the workpiece, sharpness
of the drill bit) and the operational skill of the user.
