This Fix-It Guide on electric knife repair tells how an electric knife works, what often goes wrong, how to identify an electric knife problem, and what parts and tools you will need to fix it. It then gives simple step-by-step instructions for how to disassemble an electric knife and service its driver assembly. This Fix-It Guide also refers to electrical cord repair, appliance control repair, and motor repair for more information.
How Does an Electric Knife Work?
An electric knife is a hand-held, motor-driven appliance for cutting food. It’s simple in operation: A gear assembly converts a motor’s rotary motion into a reciprocating (back-and-forth) action. The driver arm moves a pair of serrated blades, pushing one forward as it pulls the other one back.
What Can Go Wrong with an Electric Knife?
Most electric knife problems are the result of dull or unclean blades. The blades can be misaligned or the rivet that holds the two blades together can be worn. In addition, the electric cord can be faulty, internal wiring can be damaged, switches can be dirty or faulty, and bearings can be dry.
Let the knife’s motor do the work. Don’t force the knife blade down hard while cutting or you could wear out the motor.
How Can I Identify an Electric Knife Problem?
- If the knife won’t work at all, make sure power is on at the outlet; check the electrical cord. If possible, check for loose wires and reconnect them. Test the switch (see the Appliance Controls Fix-It Guide). Clean the switch by spraying with electrical contact cleaner. Lubricate the motor with one or two drops of light machine oil on each motor bearing.
- If the knife slices poorly, check the blade alignment.
- If a blade is bent, carefully press it against a flat surface. If that doesn’t work, replace both blades.
- If the electric knife is noisy, the drive gears may need to be replaced (see motor).
What Tools Do I Need for Electric Knife Repair?
- Light machine oil
- Light silicon or other grease
What Are the Steps to Electric Knife Repair?
Service an electric knife driver assembly:
- Unplug the electric knife and carefully remove the blades.
- Remove the screws at the back of housing and pull the housing apart. Be careful: The blade retainers will be loose and fall out as you open the housing.
- Remove all screws holding the driver assembly and motor to the housing. Lift the motor and driver assembly from the housing.
- Inspect mechanical parts for wear. If the fan doesn’t turn smoothly by hand, clean and lubricate the driver assembly with lightweight grease. Add a drop of light machine oil to each bearing before reassembling parts.
If you decide you can’t fix that electric knife, but the problem isn’t the motor, save the motor in your Fix-It Toolbox because you may be able to use it for another repair.