Simple Solutions That Work! Issue 5

AUTOMATIC GRINDING – CNC VERSUS ROBOTIC Once the decision is made to look for an automatic grinding solution, the foundry must then decide if the best grinding process for their castings is a CNC or robotic solu- tion. The CNC option has faster cycle times and can provide more power for heavier risers, but the robotic option provides greater flexibility. The robot can manipu- late the part being processed (bring the part to the tool) or manipulate the tool carrying out the process (bring the tool to the casting). The robot can simulate the motions/ actions of the arms and hands used inmanual grinding and provide the precision of a machine with the finesse of the human hand. The CNC requires more tooling/fix- tures while the robot can require less. The robotic solution provides the ability to use a wider variety of tools with the incorporation of automatic tool changers and tool magazines. This will allow for the use of the proper tool in the proper application and provide the ability to get more castings to 100% grind right out of the machine. Another factor in the CNC versus robot solution decision is what kind of internal expertise does the foundry currently have or will they be able to develop. The CNC option does not require as much programming and special- ized maintenance skills. The robot option will require a higher level of programming skills and robot specific maintenance knowledge, however this has been greatly diminished over the last few years with the development of some off-line programming software from the robot manufacturers and the inherent knowledge base of a younger workforce. Many community colleges and tech- nical schools are now providing classroom or on-line robot train- ing programs that can provide the basic knowledge base needed to make this transition. The robotic solution allows the foundry to more easily implement unmanned production. The flexi- bility provided by a robot will allow a single cell to perform a multitude of tasks. The robot that picks up from the loading area can be the same robot that holds the work piece and discharges the part onto the conveyor or pallet. They now have the ability to use the robot to de-gate, cut and grind risers, remove flashing and parting lines and de-burr along with the poten- tial of fully automated handling and palletization. The robotized cell will enable the foundry to orga- nize the manufacturing opera- tion with minimal supervision. The part is identified, loaded, ground and then placed on a conveyor or pallet, ready for subsequent operations. The robotic solution can provide longer tool life, repeat- able control of a precision toler- ance, quick product changeover and the ability to finish complex interior surfaces. This proven technology enhances productiv- ity, quality, safety, repeatability and the environmental integrity of the cleaning room process. FORCE CONTROL, LASER INSPECTION AND VISION TECHNOLOGY So let’s say that the foundry has decided to make the commitment and proceed with a robotic grind- ing solution, what other major advances in technology does that bring into play? Force control, laser inspection and vision technolog- ical advances have dramatically increased the viability of robotic grinding solutions for the foundry of the future. Insufficient or excessive force wastes time and valuable abra- sive tool life and potentially ruins parts. Successful robotic grind- ing has been enhanced by the NORTHAMERICA 19