A small gravity diecasting foundry that has been striving to improve working conditions and improve productivity, has built a bespoke robotic fettling unit.
After finding that the available options from the leading providers of automated systems would not meet the specific requirements the foundry were looking for, to reduce noise and vibration exposure to their employees, as well as seeking to remove the use of bandsaws on site, the MD decided to take on the engineering challenge himself, using skills learned over a 30 year plus career.
What was eventually designed was a bespoke built fully enclosed robotic unit. The unit consists of a second hand ex-welding six-axis robot with custom grippers fitted to the hand. A direct digital drive cut-off saw Rough Flash and Fine burr removal devices complete the trio of machines needed for the cell. Using a direct drive saw means cutting speeds are higher than for a conventional belt driven saw, less maintenance is required and the life of the saw blade significantly extended.
A dedicated enclosed and interlocked soundproof booth with viewing window was constructed to contain the noise but also to prevent unwanted interactions between man and machine.
Observation window ensures operators can see unit is working correctly
A custom made rotating table with multiple stations means the robot can be continuously fed with casting and once they have been trimmed to remove the feed sprues and risers, with the profile being fettled to customer requirements, the robot delivers the castings down a chute for the operator to collect. The operator then carries out any machining requirements on a three axis CNC machining centre.
The jigs to locate the castings for the robot to pick up are easily changed over by hand with no tools required and at present the foundry has in excess of 90 different castings that can be processed by this unit.
Within the robotic cell every tool had its own oiler system, however to check or refill the oilers meant shutting down the robot. The foundry have therefore designed and built a custom lubrication system that has a reservoir outside the cell which is programmed to control the lubrication to each tool. Not only has it proven to check and refill easier, but they are also using much less oil, making it a much more economical system.
Centralised unit ensures all equipment is lubricated and easy to top up