Welding Tech Tips: Robotic MIG gun selection
- Published: October 14, 2014
Choose the right gun to optimize welding automation
Gun amperage, duty cycle and cooling capacity all matter. Proper installation and maintenance is key.
The appropriate feeder placement, the right cable length and proper cable management tools can all drastically reduce downtime and costs for interrupting production for repairs.
Here are three MIG gun options to consider.
Air-cooled guns, which rely on the ambient air to cool them, typically operate in the range of 300-500 amps at about 60 percent duty cycle with mixed gases. They are ideal for welding thinner materials and work best for shorter welds on high volume applications, such as in the automotive or recreation equipment industries.
Advantages to air-cooled guns include durability and parts that are easier to maintain and less expensive to replace. They tend to have a more streamlined design and smaller working envelope, allowing greater access to smaller joint configurations. They also maintain accuracy well, which is good for consistent, repeatable welds. Air-cooled guns do have lower duty cycles compared to water-cooled guns, and they are not capable of welding continuously for as long.
Water-cooled guns offer the advantage of welding at higher amperages for prolonged periods. They generally have capacity of 300 to 600 amps, and are capable of a 60 to 100 percent duty cycle. Designed for welding on thicker materials, they are a good choice for applications in heavy equipment manufacturing or similar industries. Generally, the larger the weldment, the greater the chances it requires a water-cooled gun.
The circulators or chillers used to prevent overheating in water-cooled guns do tend to add to overall cost and maintenance, and
the parts can be expensive and time consuming to replace if they are damaged. Also, water-cooled cables have about one-fourth the copper found in air-cooled unicables, meaning water-cooled guns quickly fail if the water supply is interrupted.
A third option is a hybrid air-cooled/water-cooled gun. This is useful for applications pushing the duty cycle limits of an air-cooled model, but that don't require a complete water-cooled solution. These guns have a durable neck and unicable like an air-cooled model and offer the higher cooling capacity of a water-cooled front end. The hybrid guns, which can provide easier maintenance than water-cooled only, typically offer 300 to 550 amperage capacity at 60 percent duty cycle. SMT
Ryan Lizotte is field technical support specialist with Tregaskiss, Windsor, ON.