Robotic welding system meets all goals and helps fab shop stay competitive despite foreign competition. System reduced direct labor by 75%. One operator can run the cell versus four skilled welders. Productivity increased from 20% to 600%, depending on the type of part and length of welds. Robots provide reliable operation and consistent quality welds, facilitating JIT production.
Project Challenges
- Provide highly flexible robotic welding system that can process a wide range of part sizes and models. Primary products are large dunnage racks, ranging from 3,352.8 mm L x 2,032 mm W (132" L x 80" W), weighing up to approximately 1,360 kg (3,000 lbs.)
- Material is mild steel (primarily tubing, plus some flat stock and sheet metal), from 12.7 mm (0.5") to 1.5 mm (0.06") thick. Welding different gage materials, like 1.5 mm (0.06") (16-gage), can be challenging, particularly the T-joints. Most welds are single-pass, ranging from 4.06 mm (0.16") L to 304.8 mm (12") L. Depending on size and model number, parts require up to 200-600 different welds totaling 400 to 900 inches.
- Provide flexibility to perform standard or pulse welding, and weave, touch-sense, seam-track functions, as needed.
- Reduce the need for skilled welders.
- Improve productivity, provide consistent high-quality welds.
- Enable quick manual changeover between batch runs.
Motoman Robotics Solution
Motoman Robotics provided a custom HP50-20 welding solution, including:
- (2) Motoman HP50-20 robots with two NX100 DR2C controllers.
- (2) Robot base risers.
- (2) Motoman MHT-1500 headstock/tailstock positioners with 3,000-kg (6,615-lb) payload; 10.6 rpm headstock speed; and 3.32-second 180º sweep. Rated at 152 mm (6") off-center of CG at rated load and 50 mm (2") overhang CG at rated load. MotoMount™ compliant tool mounting system included.
- (2) Miller welding packages, including AutoAxcess 450 power sources.
- (2) Motoman 500-amp, air-cooled Tough Gun torch packages.
- (2) Reamer/sprayer nozzle cleaning stations.
- (2) Motoman pneumatic wire cutters.
- (2) Operator stations (one primary, one secondary) on stand-alone pedestal. Functions: Job Start, Emergency Stop, Hold, Alarm Reset, and Servo Power-up. Palm button for cycle start activation. Ready signal light and alarm indication light. Positioner auto/manual switch. Thumbwheel switch for program selection (up to 100 programmed jobs) and manual positioner jog joystick.
- (1) Common equipment base for NX100 controllers and welding power supplies.
- (1) Cell guarding package, including 2.5-m (8') H woven wire perimeter safety fence; one access gate with positive break safety switch; arc flash protection curtains; light curtains at positioner stations; and two 3-color safety beacons with audible alarm.
Fixtures/Tooling Details
Customer provided their own tooling, including two sets of pneumatically clamped fixtures (one per positioner). Bolt-on fixtures include part-present sensors. Changeover takes an average of only 5-10 minutes.
Ref: ACS-079