Three-lathe cell, 20-year-old robot
Three vertical lathes, 100 kg parts, a freezing hall, and a 20-year-old second-hand robot. One cell.
2018–19 · GreenBau, Romania · Industrial robotics
The problem
A small machine shop makes parts for large European water lines. Some parts weigh 100 kg and go through three machining steps that needed three operators at all times, in a hall with poor insulation and no climate control. The process was clumsy, slow and unsafe. With partial EU funding for automation, the plant wanted it automatic, with manual work still possible when needed.
Requirements
- Six cylindrical part types with different diameters and routings, STAR (all three machines in parallel) and RING (one part through all three machines in series)
- Immune to the hall’s conditions and changing light
- Minimal operator interaction
- Integration with three vertical lathes
- Use a 20-year-old second-hand robot the plant had already bought
What was built
- A cell reaching three lathes plus two intermediate stations between machines, to keep a buffer and run continuously
- Loading and unloading from roller conveyors
- A 2D camera that finds each part on the input conveyor by part type
- A gripper with modular fingers that handles every part type
- Safety with a fence, three interlocked doors, emergency stops, request-to-enter buttons and status stack lights
- Full integration with all three machines through Ethernet/IP I/O modules
- Pneumatic cylinders that open and close the machine doors automatically
- Program changes by swapping a memory card in the PLC, with no HMI and no technical knowledge needed
Challenges
- Talk to a 20-year-old robot from a modern cell
- Bridged Profibus, DeviceNet and Ethernet/IP into one control system
- Reliable vision while the light changes all day
- Developed robust image processing for the input conveyor under variable lighting
- Fit the robot’s reach and keep room for manual work
- Mechanical layout planned around both the work envelope and the operator
Technology
KUKA · 3 × vertical lathe · 2D vision · Modular gripper · PLC · Profibus · DeviceNet · Ethernet/IP
At a glance
- ROBOT
- KUKA, 20 years old
- MACHINES
- 3 × vertical lathe
- PARTS
- 6 types, up to 100 kg
- VISION
- 2D on input conveyor
- COMMS
- Profibus · DeviceNet · Ethernet/IP
My role. Designed and commissioned the cell layout, gripper, safety, robot programs and PLC
Screens
