The rule that held for years in traditional manufacturing plants — one robot for every machine — had stopped being sustainable for us. Shrinking floor space, rising investment costs and the difficulty we faced in finding qualified operators pushed us to use our existing resources far more intelligently. That was the point at which we moved to an architecture where, using the Sora Robotic infrastructure, a single robot can feed 2, 3 or even more machines without interruption. In the process we did not only bring costs down; we also raised the square-metre efficiency of our production line.
How Is the Efficiency Calculation Made in an Automation Investment?
When we started the Sora Robotic installation, we knew our biggest mistake would be to act on instinct. We saw on the floor ourselves that what determines how many machines a robot can keep up with is a purely mathematical cycle time balance. The efficiency of the system is set by the ratio between the machining time of the part inside the CNC and the intervention time the robot spends loading and unloading. If the robot is still busy at another machine when a machine finishes its operation, idle time for that machine becomes unavoidable.
A short note from our own field experience: Planning so that the robot’s utilisation stays around 85-90% keeps the system from locking up and, in the long run, keeps the line from stopping.
Which Robotic Layout Is More Advantageous in a Factory?
During implementation we spent a good deal of thought on how to position our Sora Robotic robotic system according to the physical conditions of our factory. Two basic layout options were in front of us: circular cells and rail-mounted linear lines. For plants like ours, working in a confined area and producing medium-sized parts, circular arrangements with the robot placed at the centre of 2-3 machines gave a very efficient result. If you are planning large-scale industrial lines with much longer cycle times, however, we observed that linear systems where the robot travels on a rail (a 7th axis) can serve a far greater number of machines.
Does Dual Gripper Technology Really Change Production Speed?
The biggest bottleneck we came across in operation was the dead time the robot spent inside the machine after the CNC door opened. In the early days, using a single gripper, we noticed that the machine sat idle for a long time while the robot picked up the part, set it down and clamped the new one. Once we integrated a dual gripper into our Sora Robotic configuration, the picture changed completely. Thanks to that mechanism at the end of the CNC robot arm, the robot waits at the door with the raw part in hand, and as soon as the door opens it takes the finished part, rotates 180 degrees and clamps the new one within seconds. This simple but effective change pulled the in-machine handling time down from around 40 seconds to a band of 5-8 seconds and raised our overall line efficiency by 40%.
A detail our team noticed: If you work with different parts, you must always base the mathematical calculation on the part with the shortest machining time; otherwise blockages can appear in the system flow.
The most valuable lesson we took away when starting a new automation project was that everything is hidden in that detailed analysis at the design stage. This multi-machine feeding system we built with Sora Robotic proved to us that, combined with the right hardware and precise simulation, a single investment can keep more than one machine running at full capacity.