Spot Welder

Make: Miller

Model: LMSW-52

Resistance spot welding is a process in which contacting metal surface points are joined by the heat obtained from resistance to electric current. The Miller LMSW-52 Air-Cooled Spot Welder is a lightweight unit that is portable, easy to operate and excellent for welding mild, galvanized or stainless materials.

Description

LMSW-52 spot welder manual [1]

Here is an example of spot welding and some good basic information.

Documentation

Owner's Manual

Terminology

Tongs-

Training

Operation

Here are some general setup rules of thumb:

The CFH gas setting should be roughly 2x the weld cup size. If you were to use a #7 cup the gas flow should be set to 14 CFH.
The tungsten stick-out from the cup should be no more than the cup diameter. Using a #7 cup would allow for a maximum tungsten stick-out of 7/16"

Demonstration

The demonstration consists of two parts. For the first part you will need to setup the welder and safely attempt to weld a bead. The second part will require you to show knowledge of safely using the grinder and successfully grind a point on a tungsten rod.

General Procedure

Ensure the material being welded should be clear of any oil or dust
Turn on the spot welder
Place the material being welded between the clamps.
Clamp down on the two pieces of material for no more than 5 seconds.
Grab workpiece with a set of pliers, and open the clamp.

Safety

Don't exceed gas pressure past specified value
Don't weld with gas off
Always use a welding helmet and proper PPE
Don't weld in wet gear or standing water
Don't unscrew regulator adjusting screw all the way out
Make sure ground clamp is connected to work

Certification

Foxtale Course

Troubleshooting

Maintenance

General maintenance

The welding torch and cables should be inspected on a regular basis. Look for any signs of cracking or cuts in the cables.

Specific Maintenance Tasks

Maintenance Procedure	Frequency	Done By
Check Argon Pressure	Before Use	Student/Tech
Check Coolant Flow	Before Use	Student/Tech
Inspect collet & Cup	Before Use	Student/Tech