Projects

Automated Production Test Stand for a Welding Manufacturer

The Challenge

Miller Electric assembles Metal Inert Gas (MIG) and Tungsten Inert Gas (TIG) welding machines, conducting 10 end-of-line tests to verify the functionality before shipment. Their previous approach to assembling MIG and TIG welding machines combined a manual and a semi-automated testing system across multiple stations, including a custom-built stand that couldn’t integrate all 10 tests and required difficult test setup, slowing overall test time. This testing process led to inefficiencies, with time-consuming processes and inconsistencies, especially when skilled operators weren’t available.

The welding manufacturer engaged ACS to develop an automated production test stand that would consolidate all 10 tests in one station. Miller Electric’s goals included:

  • Reducing dependence on manual testing and skilled operators.
  • Implementing the Acselerant™ software platform for adaptable testing sequences.
  • Safely handling the unique voltages, frequencies, and high currents of welding machines.

The Solution

ACS engineers designed an end-of-line production test stand that fully integrates all 10 tests for Miller Electric’s small-frame welders. When the welder arrives at the production test stand via conveyor, the operator connects power and gas, and then initiates the testing sequence through two-hand safety controls.

A range of sensors, the custom Acselerant software, and automated safety protocols ensure test accuracy and operator safety. Below are the key engineering solutions incorporated into the design.

Vision System for Drive Wheel

To measure drive wheel speed without physical contact, ACS engineers implemented a vision system that tracks an etched line on the wheel’s surface. This non-contact approach avoids wear and alignment issues, enhancing test accuracy and efficiency and minimizing operator intervention.

Cooling Fan Detection

With the welder’s case removed, the ACS production test stand uses a differential pressure sensor to detect airflow by sealing the Unit Under Test (UUT) for a slight pressure difference. This approach accurately assesses cooling fan functionality without external interference.

Handling High-Frequency, High-Amperage Requirements

The ACS team designed the stand to manage high-power outputs safely and accommodate the varying duty cycles of different welder models. Signal conditioning circuitry ensures accurate readings across models, maintaining both operator safety and test accuracy.

Operator Safety Features

To safeguard operators, ACS incorporated a two-hand control system and a protective guard that lowers during testing into the test stand. Safety interlocks and power dissipation systems minimize risk while allowing efficient, safe testing.

Ergonomic Design

To ease the repetitive action of operators connecting and disconnecting UUTs, the ACS design places all connection points, cables, and components in a near shelf area inside the stand’s guard assembly. This design minimizes how far operators need to reach forward for each test cycle, reducing their strain.

The Outcome

The collaboration with ACS resulted in an automated testing system that meets Miller Electric’s goals for its full run off testing. By integrating all 10 tests into a single production test stand, ACS’ system streamlines the testing process, reducing time per unit while ensuring high-quality, consistent results across both models of MIG and TIG welding machines.

The vision system’s non-contact design efficiently measures drive wheel speed and accommodates different wheel configurations, reducing setup time. Signal conditioning circuitry supports high-frequency, high-amperage outputs, ensuring safety and accuracy across all units.

The ergonomic layout, developed in collaboration with the welding manufacturer, reduces operator strain, supporting efficient and safe operations across shifts. The Acselerant software platform also provides Miller Electric with the flexibility to reconfigure test sequences to meet evolving needs, making it a future-ready solution.

Key Features

  • Integrated and automated run of all 10 end-of-line tests for small-frame welders
  • Vision system measures drive wheel speed without physical contact, avoiding wear and alignment issues to enhance test accuracy and efficiency
  • Differential pressure sensors accurately detect cooling fan functionality without external interference
  • Signal conditioning circuitry safely manages high-frequency (up to 40 kHz), high-amperage (up to 300 A) testing across different welder models
  • Operator safety features include two-hand controls, a protective guard, safety interlocks, and power dissipation systems
  • Ergonomic design reduces strain for operators connecting and disconnecting welders

ACS Services

  • Mechanical engineering and design of the test stand for the welding manufacturer
  • Data acquisition and software development for the test stand
  • Factory and site acceptance testing