1、 Core component functions and problem impacts
wire feed roller
Function: The motor drives the wire feeding wheel to "bite" and push the welding wire through friction, making it pass through the welding gun steadily and uniformly.
Problem impact: Worn or soiled wire feeding wheels can cause unstable, shaking, wire jamming, and even wire stoppage, resulting in unstable arc, poor weld formation, and increased splashing.
contact tip
Function: At the end of the welding gun, the welding current is conducted to the welding wire, and the welding wire is guided into the molten pool carefully.
Problem impact: Worn or blocked conductive nozzles can cause arc drift, deviation of wire feeding path, increased splashing, and in severe cases, adhesion between the welding wire and the inner wall of the conductive nozzle (burning of the conductive nozzle), leading to welding interruption.
2、 Daily maintenance and inspection (before and after each welding)
Wire feeding wheel:
Visual inspection: Remove the wire feeding wheel and check for metal shavings, oil stains, and dust accumulation in the wheel groove. Check if the wheel groove shape is still a clear U-shape or V-shape, and if it has worn into an irregular shape.
Cleaning: Use compressed air to blow away particles from the wheel groove. For stubborn oil stains, anhydrous ethanol can be dipped in non-woven fabric for wiping. It is strictly prohibited to use oil or lubricants to lubricate the wire feeding wheel.
Pressure adjustment: Check the pressure of the wire feeding wheel. The correct pressure is: it can smoothly feed the wire, and when not feeding, the wire can be pressed out by the wire feeding wheel with slight tooth marks, but will not be flattened or severely deformed. Excessive pressure is a common cause of coating peeling off on the surface of welding wire and blockage of wire feeding tube.
Conductive nozzle:
Visual inspection: Check if there is any splashing adhesion at the end of the conductive nozzle, and if the internal aperture has become larger or rounder due to wear.
Cleaning: Use a one-on-one brass brush to clean external splashes. It is strictly prohibited to use steel tools such as files and pliers for rough cleaning, as this can damage the conductive nozzle.
Path inspection: Thread a new piece of welding wire through the back end (big end) of the conductive nozzle and feel the resistance. If the resistance is significantly too low or the welding wire shakes in it, it indicates that the aperture has been worn and needs to be replaced.
3、 Regular scale maintenance and replacement
Wire feeding wheel:
Cleaning cycle: A scale cleaning should be performed every 80-200 hours of use or after replacing 2-3 rolls of welding wire.
Replacement cycle: When the wheel groove shows obvious wear, deformation, or uneven depth, it needs to be replaced immediately. The service life of a wire feeding wheel is usually 10-20 times that of a conductive nozzle.
Match the position: Be sure to use a wire feeding wheel that matches the diameter and type of the welding wire (such as V-shaped groove for solid welding wire, U-shaped groove for flux cored welding wire, gear groove for aluminum welding wire).
Conductive nozzle:
Replacement cycle: The conductive nozzle is a consumable item and should not be replaced only after use. Suggest batch replacement and establish replacement records. Replace immediately when the following situations occur:
The arc begins to become unstable and makes a "crackling" sound.
The wire delivery is starting to experience a stuttering sensation.
The quality of weld formation has decreased.
Correct installation: When installing a new conductive nozzle, tighten it by hand and then use a tool to tighten it about 1/4 turn. Over tightening can damage the threads. Before installation, stretch out a piece of welding wire to guide the conductive nozzle to screw on smoothly.
4、 Troubleshooting process
When there is a wire feeding problem, please troubleshoot in the following order:
Good sales step: Check the conductive nozzle
Phenomenon: Unstable arc and poor wire feeding.
Action: This is a relatively fast and simple inspection. Replace the conductive nozzle directly with a new one. If the problem is solved, it indicates that the old conductive nozzle is worn or blocked.
Good step: Check the wire feeding wheel
Phenomenon: wire feeding shaking, wire jamming, abnormal scratches or flattening on the welding wire.
get some action:
Check if the groove type of the wire feeding wheel matches the diameter of the welding wire.
Check if the pressure of the wire feeding wheel is too loose or too tight.
Clean the wire feeding wheel groove.
If the wear is severe, replace the wire feeding wheel.
Step 3: Check the wire feeding hose
Phenomenon: Continuous wire feeding resistance is high.
Action: If the problem persists after replacing the conductive nozzle and wire feeding wheel, it is likely that there is dirt or wear inside the wire feeding hose. It needs to be disassembled and cleaned with compressed air or replaced with a new pipe.