System meets/exceeds all project goals and objectives. Welding time has been reduced from approximately 16-18 hours manually to 1.5 hours using the robots. (Customer cannot tack-weld assemblies fast enough to keep up with robotic welding cell.) System provides flexibility and capacity to handle wide range of current and planned production parts. Robots improve productivity and provide consistent, high-quality heavy-deposition welds.
Project Challenges
- Provide highly flexible robotic system to reduce manual welding on two sizes of large, pre-tacked/partially pre-welded frame assemblies, with capability to add other products in the future.
- Frames are 6.35-9.525 mm (1/4"/0.25"-3/8"/0.375") mild steel and range from 2.87-3.76-m (113"-148") L and weigh approximately 500-818 kg (1,102.5-1,803.7 lbs) each.
- Robot must make approximately 260 welds on one size part, and 320 welds on the other. Welds range from approximately 76.2-1,828.8 mm (3"-72") L .
- Improve productivity, reduce cycle time.
- Provide consistent, high-quality welds.
Motoman Robotics Solution
Motoman Robotics provided a flexible welding solution, including:
- (2) Motoman HP50-20 robots with (2) NX100 controllers in DR2C configuration (two robot controllers interfaced as a single controller with one programming pendant; includes equipment package to separate controllers for individual control, if desired).
- 14.02-m (46') L robot servo track with rack-and-pinion drive and dual carriages for robots and wire drums.
- (2) Miller Auto Axcess 450-amp weld packages.
- ComArc dual-robot seam-tracking and 200V touch-sensing package.
- (2) Motoman Tough Gun torch packages – 450-amp, water-cooled, with water circulators and weld dress-out packages.
- (2) Reamer/sprayer nozzle cleaning stations.
- (2) Motoman MHT-3000 headstock/tailstock positioners, each with 6,300 kg (13,891.5 lb) payload capacity, 5-second 180-degree rotation; and 6.7 rpm headstock speed. Tailstock through-hole and rotary air coupler included.
- (2) Mobile tailstock sub-bases with AC servo-drive adjustment for part length variation; 3.96-m (13') travel; and push-button operation on tailstock pendant.
- Fixture package, including two fixtures per positioner (one for each size frame).
- (2) Operator stations.
- Common equipment base for NX100 controllers, welding power supplies, ComArc enclosures, water circulators and electrical disconnects.
- Cell guarding package that meets ANSI-RIA15.06-1999 safety standard. Includes 2.4-m (8') woven-wire perimeter safety fence with (2) access gates and positive-break safety switches; arc flash protection curtains; light curtains at each positioner load/unload station (6.1-m/20' maximum distance apart); robot home switches; and servo track station zone switches.
Fixtures/Tooling Details
Motoman Robotics provided two sets of fixtures for each MHT-3000 positioner (one set of fixtures, per positioner, for two part numbers). Each fixture locates one end of a large part that spans between the headstock and tailstock. Manually clamped fixtures include hardened details. Sensors are not included.
Ref: ACS-098