Weld Heads

The precision series of welding heads from MacGregor Welding Systems provide a flexible and robust micro welding head with superior performance throughout the force range specified. All models are based upon MacGregor's welding head module and can be fitted with displacement monitoring. The Universal Series of welding heads offers the user a tool free adjustment of the weld head height and base plate assembly.

The precision spot welding heads offer a performance focused design that ensures the weld head is capable of providing accurate and consistent welding force, monitored via a force gauge. The low moving mass design and low friction bearing system allow the welding head to react to weld collapse more rapidly than conventional designs. The bearing system provides exceptional offset loading performance and consistency of welding electrode location and orientation. The bearing system is adjustment free and does not require maintenance.

The welding heads are available in three basic configurations:

  • Opposed: In line welding electrodes with single welding head and fixed lower electrode.
  • Parallel Gap: Parallel welding electrodes mounted in a compliant tip assembly.
  • Twin: Parallel welding electrodes with twin welding modules for individual force control and compliance.

Precision Welding Head Models: 

Welding Head Modules

MacGregor Welding Systems manufacture a range of welding head modules varying from the mini module to the high force module. Modules provide the dynamic control of the welding electrode and are ideally suited when a complete resistance weld head is not required, such as when integrated into an automation system.

Precision Opposed Welding Heads

Opposed Welding

Opposed welding requires that the electrodes can make access to both materials allowing the materials to be held under pressure between the upper and lower electrode. In opposed welding, the current flow is through one electrode, through material A, through material B and then through the return electrode. Opposed welding offers the most simple of the welding geometries and the most commonly used. Opposed electrode welding ensures that all the weld current flows through the weld joint.

Precision opposed welding heads are available in a number of formats as follows:

Standard and high force opposed  welding heads are available with treadle, flexline or pneumatic actuation.

Parallel Gap / Series Welding

Parallel gap welding involves accessing the weld area from the same direction with both electrodes. In parallel gap welding, the gap between the electrodes is typically less than 1 mm with both electrodes contacting the same part. The current flow through the weld materials is accomplished through the variation is material and interface resistances as the weld occurs. When the weld starts, the majority of the current flows though the material in contact with the electrodes. Because current always follows the path of least resistance from the negative to the positive electrode, the current flow will initially be through the upper material. As this material heats, the material resistance increases and the contact resistance between the upper and lower material decreases. At this point, current flows through the interface and through both materials. Because there are two current paths, the part-to-part interface resistance is critical. Product cleanliness and surface condition will have a greater effect in this type of weld than in an opposed or step weld where the current is forced through the part-to-part interface.

Series welding involves the same geometry and principles as parallel gap welding but has an electrode gap greater than 2 mm.

Parallel gap / series welding heads are are available in a number of formats as follows:

Standard and high force parallel / series welding heads are available with treadle, flexline or pneumatic actuation

Displacement Control

All weld heads are available with embedded displacement control transducers to interface with the power source providing the ultimate in control of monitoring of weld collapse.

Constant Force Welding Head 

The Constant Force Weld Head by MacGregor Welding Systems offers the ultimate in intelligence and functionality and provides a constant welding force over a linear operating range of 20mm. Force monitoring is provided ensuring welds are only triggered when the correct force is set. A digital readout provides force indication in pre-selected units and an RS232 port is incorporated for data logging.

Mach One Closed Loop Force Control Motorised Welding Head

This unit features embedded load cell for the ultimate in force control enabling welding pressure to be pre programmed as part of the weld schedule.  This head is ideal for applications where a number of different joints are made with one weld head.

Weld Head Accessories

Accessories available include electrode holders, stand or special purpose which can be built to customer specification.  Interconnecting cables, electrodes and digital force gauges are also available.