Miller Multimatic 220 Welder

Asmbly has two Multimatic 220 multi-process welders. These have both MIG and AC/DC TIG capabilities, each of which has its own prerequisite class. One's owned by Asmbly, the other's hosted by Jon.

Members must complete the MIG Welding Class before using this tool

Members must complete the TIG Welding Class before using this tool

Safety

Universal Safety

• Be aware of your surroundings, especially when handling large materials.
• Do not approach anyone operating equipment. Stand patiently in their field of view.
• Always wear appropriate personal protective equipment (PPE), including welding gloves, a welding helmet with appropriate shade, flame-resistant clothing, and safety boots.
• Ensure proper ventilation when welding to prevent exposure to fumes and gases.
• Keep flammable materials away from the welding area.
• Do not weld on containers that have held combustibles unless properly prepared.
• Always disconnect power before performing maintenance.

Equipment-Specific Safety

• MIG Welding Class is required to use this tool.
• Do not touch live electrical parts; always assume the workplace and electrode are electrically live.
• Always check that the machine is properly grounded and all cables are securely connected before operation
• Ensure the ground clamp is securely attached to the workpiece.
• Use proper shielding gas to minimize exposure to harmful fumes.
• Keep all covers and panels in place during operation.
• Avoid working in wet or damp environments when operating the equipment.

Etiquette

• Maintain a clean and organized workspace
• Follow safety protocols to minimize risk of injury to yourself or others
• Report any equipment malfunctions

Use Case

The Miller Multimatic 220 AC/DC is a versatile multi-process welder capable of MIG, Stick, and TIG welding, suitable for small fabrication shops, maintenance, and hobbyist applications. It supports both 120V and 240V power inputs for various work environments.

Material Capacity

• Mild Steel 24 ga. - 3/8 in. (MIG)
• Mild Steel 24 ga. - 1/4 in. (TIG)
• Aluminum 24 ga. - 1/4 in. (TIG)

Resources

• Users Manual

Common Problems

Issue	Definition	Possible Causes	Solution
No arc start		Poor ground connection	Ensure ground clamp is attached securely
Excessive spatter	scattering of molten metal particles that cool to solid form near weld bead.	Incorrect voltage/wire speed. Amperage too high for electrode Arc length too long or voltage too high	Adjust settings per material thickness Decrease amperage or select larger electrode Reduce arc length or voltage
Porosity in weld	small cavities or holes resulting from gas pockets in weld metal.	Arc length too long Damp electrode Workpiece dirty	Adjust settings per material thickness Decrease amperage or select larger electrode Reduce arc length or voltage

Maintenance

This tool is owned by Asmbly Makerspace for the use of its members. Please submit a problem report if maintenance is required.

Maintenance

This tool is owned by Jon Eklund and hosted at Asmbly for members to use. Please submit a problem report if maintenance is required.