Idle Roll Pressure Setting

B-7	OPERATION	B-7

The idle roll pressure is set at the factory. Two-roll feeders are set with the pressure adjustment knob backed out two turns from full pressure, and four-roll feeders are set backed out three turns. This is an approximate setting. For small wire sizes and aluminum wire the optimum idle roll pressure varies with type of wire, surface condition, lubrication, and hardness. The optimum idle roll setting can be determined as follows:

Two-roll wire feeders:

1.Press the end of the gun against a solid object that is electrically isolated from the welder output and press the trigger for several seconds.

2.If the wire “birdnests”, jams, or breaks at the drive roll, the idle roll pressure is set too high. Back the pressure adjustment knob, Figure B.4, out 1/2 turn. Run new wire through the gun and repeat step 1.

3.If the only result is drive roll slippage, loosen the gun cable clamping screw on the conductor block and pull the gun cable forward about six inches. There should be a slight waviness in the exposed wire. If there is no waviness, the pressure is too low. Increase the pressure setting 1/4 turn. Lock the gun cable in place and repeat steps 1 and 2.

Four-roll wire feeders:

1.Release the incoming idle roll and perform the pressure setting procedure for two roll feeders to set outgoing idle roll pressure.

2.After outgoing pressure is set, determine how many turns away from full pressure the setting is.

3.Set both idle roll tensions to this setting. Engage both idle rolls before welding. For most applications, best wire feeding will occur when both idle roll pressures are set the same.

FIGURE B.4 – IDLE ROLL PRESSURE SETTING.

PRESSURE

ADJUSTMENT

KNOB

LN-742 & LN-742H

LN-742, LN-742H specifications

The Lincoln LN-742H and LN-742 are renowned models in the realm of industrial welding equipment, specifically designed to cater to the needs of professional welders and fabricators. These machines stand out for their robustness, advanced technology, and ease of use, making them popular choices in various industries, including construction, automotive, and manufacturing.

One of the main features of the Lincoln LN-742H and LN-742 is their powerful Arc control capabilities. The machines are equipped with innovative technology that allows for consistent arc stability, which is crucial for achieving high-quality welds. The adjustable arc force enables users to tailor the welding parameters to their specific applications, facilitating optimal penetration and minimal spatter.

The LN-742H model is particularly notable for its enhanced portable design, making it easier for operators to transport the machine to different job sites. This portability does not compromise its power, as it offers a high output suitable for both thin and thicker materials. Moreover, the LN-742 model comes with a highly efficient cooling system that ensures the machine runs smoothly without overheating, even during prolonged use.

Both models feature an intuitive user interface that simplifies the welding process. The digital display offers real-time feedback on the welding parameters, allowing welders to make precise adjustments as needed. This feature is especially beneficial for beginners, who may be unfamiliar with optimal welding settings.

Another impressive characteristic of the Lincoln LN-742H and LN-742 machines is their versatility. They support various welding processes, including MIG, TIG, and stick welding, giving users the flexibility to choose the most suitable method for their projects. This adaptability makes these models an ideal solution for shops that handle a wide range of welding tasks.

Durability is a significant consideration in the design of the LN-742H and LN-742, as they are built with high-quality materials that withstand heavy use and challenging conditions. The rugged construction extends the lifespan of the machines, reducing the need for frequent repairs and servicing.

In summary, the Lincoln LN-742H and LN-742 welding machines exemplify advanced engineering and user-focused design. Their combination of powerful performance, portability, user-friendly features, and versatile applications makes them essential tools for professionals in the welding industry, paving the way for excellence in metal fabrication and repair.

OPERATION