Things You'll Need
7,000 to 9,000 RPM DC motor
Empty bleach jug
Laptop power adapter
PVC pipe cap (6-inch diameter)
Make sure the holes on each side of the PVC pipe cap for the trimmer string are level to keep the cap balanced when it spins. Purchase a power supply that provides enough DC voltage to power the motor.
Be cautious when working with electrical components to avoid potentially hazardous situations. Wear eye protection such as safety glasses as well as gloves when using the weed trimmer.
A weed trimmer, commonly known as a string trimmer, is used to clear weeds quickly without having to bend over and pull the weeds by hand. This device is essentially a string rotating at a high speed. Weed trimmers are often used to clean the trimming along fences, sheds, garages and other edges that are hard to access. Build your own weed trimmer with the right tools and take advantage of this valuable maintenance device.
Cut off the end of the power adapter that goes into the laptop.
Separate the wires so that you have several individual wires. Strip about an inch of insulation off the end of each wire.
Plug the power adapter in a wall outlet. Make sure that none of the wires are touching each other. Place the DC motor next to the power adapter to test the connections. Pick up the wires by the insulated parts and touch the wires from the adapter to different connection wires from the motor.
Make a note of which combination of wires gives enough power to spin the motor.
Unplug the adapter and affix the wires from the adapter to the appropriate motor wires with electrical tape.
Place the motor on the shovel handle so that the motor housing reaches approximately 2 inches above the bottom of the shovel handle. Affix the motor to the handle with the hose clamp and tighten the screw on the clamp to secure the motor.
Insert a screw through the clamp into the handle from the side. This is to prevent the clamp from rotating on the handle.
Cut the empty bleach bottle in half. The bottle's handle should be in the center of one of the halves.
Cut a hole approximately the same size as the shovel handle in the half of the bleach bottle without the handle. Slip the bottle onto the shovel handle.
Drill two or three holes in the empty bottle's neck and into the shovel handle to affix the handle to the bottle. Use screws to secure the combination.
Use the drill to make a hole through the top side of the PVC pipe cap. It should fit the drive shaft of the motor. Drill two additional holes on the sides of the cap for the trimmer string. They should be on opposite sides of the cap.
Slide a nut on the drive shaft and secure it to the top of the threading. Insert the drive shaft through the hole on the top of the PVC pipe cap. Secure the drive shaft by placing a nut on either side.
Use scissors to cut 6-inch pieces of trimmer string. Insert them through the holes on the sides of the PVC pipe cap. To secure the cap, tie a knot with the strings on the inside of the cap.
Use several zip ties to affix the laptop power adapter to the shovel handle.
When you are ready to use the weed trimmer, simply plug the adapter into an extension cord. Plug this extension cord into a power outlet.
Scarlett Gauthier began writing in 2003. Gauthier has a graphic design/arts DVS from Rosemount Technology Center in Montreal.