The document summarizes a university capstone project to design and build a robotic welding cell. Key details include: - The project involved designing a semi-automatic welding cell using a robotic welder to manufacture exhaust pipe assemblies for Bauer Welding and Metal Fabricators. - Various fixtures were designed and built to securely hold parts for welding, dimensional checks, and pressure testing. - Automation and safety systems like a PLC, safety enclosure, and light curtain were incorporated to enable safe, repeatable robotic welding of parts. - The completed cell cost $141,200 and demonstrated the viability of the pulsed GMAW welding process developed in the previous capstone for production applications.

1. University Of Wisconsin – StoutCapstone 2: Robotic Welding CellBenjamin FerronRyan SchleisJustin ProkashRichard PikeJonathan ErlMatthew Henderson Nicholas TomsyckRobert IhrkeRolf SevertsonJacob Stephany

2. Overview:Bauer Welding and Metal FabricatorsFounded in 1946 by Donald K. BauerSpecializes in tube bending, fabrication, and weldingUtilizes Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), laser cutting, plasma cutting, and multiple GMAW robotic welding cells to provide a diverse array of customers with high quality weldmentsCustomers include: Kawasaki, Arctic Cat, Toro, Cummins, Kubota, New Flyer, and Winnebago

3. Project ScopeDesign and build a demonstrable semi-automatic robotic welding cell and showcase a common industrial robot application in the UW-Stout robotics labSubstantiate repeatability of the pulsed Gas Metal Arc Welding (GMAW-P) process developed in Capstone I for production use by manufacturing representative weldments in the constructed cell

4. Welding Considerations Welding aluminized steel to mild steel has been a nagging manufacturability issue at BauerCurrent process uses expensive consumables (stainless steel wire, Helistar GV blended shielding gas)Current process yield is poor and joint leaks are commonPulsed Gas Metal Arc Welding (GMAW-P) process developed on test pieces in Capstone IWelding process needed to be substantiated on parts with dimensional variability typical of multiple bend tubes

5. Exhaust Pipe AssemblyRepresentative of a part manufactured by BauerConsists of a two-bend aluminized tube, square flange, diamond flange, and three heat shield bracketsAll materials donated by Bauer

6. Tailstock AssemblySupports weld fixture positioning table using a floating pillow block bearingMinimizes deflection during rotation of robot positioner to maintain positional accuracyStructurally soundTied into robot frame Adaptable to other fixtures

7. Weld FixtureMaximizes clearance for welding torchPoka-Yoke designMounting system adaptable to other fixturesTwo fixtures allow for increased cycle efficiency

8. Dimensional Check FixtureEnsures assembly maintains critical tolerances

9. Verifies

10. Rotation of flanges

11. Position of brackets

12. Poka-Yoke designPressure Test FixtureCustomer requires that finished parts be pressure testedWired to PLC for semi-automationPoka-Yoke design

13. Control SystemEaton PLC controls main operationsWelding operationPressure testService/reset functionsEaton HMI provides a graphical user interface (GUI)Andon light indicates operation status of robot

14. Safety EnclosureComply with industrial safety standardsRequirement to run robot in full speed automatic modeManage safety hazardsFlash screens shield bystanders from weld flashLight curtain and door interlock prevents entry into cell while robot operatingEnclosure is NOT a substitute for PPE

15. Safety AssessmentRisk Codes Assigned Severity Before and after analysis Probability Before and after analysisCountermeasures to prevent risks

16. Cost AssessmentRobot/positioner/welder$125,000PLC Automation$7,000Safety Enclosure$2,000Weld Fixture$3275Tailstock$335Pressure Test Fixture$890Dimensional Check Fixture$2,700Total cost for entire cell: $141,200

17. Cost AssessmentStarting Budget - $1000Light Curtain Transmitter/Emitter - $158.00Steel for Fixtures - $43.22Toggle Clamps - $56.82Pressure Sensor Heads - $87.94Sensor Amplifiers - $222.60Steel for Enclosure - $239.14Cable for Control System- $72.80Safety Signs - $59.6 Total - $940.12

18. ConclusionsSubstantiated that welding process developed in Capstone I is repeatable for production use on parts with typical dimensional variability found in multiple plane bent tubesProduced representative parts with excellent visual and sealing weld qualityConstructed a semi-automated welding cell in the UW-Stout robotics lab around the ABB IRB-1400 robot that is safe and straightforward to operate