You Have a Machine Shop and Cannot Meet Deadlines, Read this Blog Post
You have a machine shop and you are short in time, you want to reduce your setup time and reduce your price? Well, you are in the same situation than most machine shops. In fact, most machine shops have difficulties to increase quality, reduce setup time / cycle time and reduce their delivery time because of the lack of workforce. The solution is generally to place a robot in front of the machine and make it infeed and outfeed the parts. That being said, what do you really need to achieve this task with a robot.
Since I have seen a lot of different machine tending cells, I will try to give you the best advice I can so you can have a better idea of what is generally happening in the industry.
I have seen some very impressive robotic machine loading cells with huge robots rolling on rails with very specific tools and stuff, but at the end of the day, what you need is to be able to tend a CNC machine. This task was done by a human worker, simply reposition the worker to other tasks and replace it by a robot that has the same size. Collaborative robots for example are robots that are relatively small, easy to program and safe for human-robot collaboration. In other words, it is an arm that replaces a human arm.
These robots do not need particular programming courses, do not need additional safety devices and are relatively cheap.
Programming the robot can be done by teaching method, in fact, by moving the robot to its different points, it can record and re-do the same program afterwards. If you are changing your production every now and then, the robot can be reprogrammed within a couple of minutes.
Regular industrial robots need complex programming knowledge. If you are changing the part type, you need to reprogram it, if you change your production every day, well, you need to program the robot everyday (it is as complex as your CNC machine).
Regarding safety devices, since the robot has embedded force sensors, the robot can feel if there is an abnormal impact during the robot path.
Regular robots need to have safety fences from other human detection devices to prevent (actually avoid) human-robot contact. These types of fences take a lot of place on the shop floor. They are also kind of expensive.
Relatively Cheap: For a standard Universal Robots UR5, the price point is about $35,000 USD. As regular industrial robots cost about the same price (for an equivalent model) you still need to add other devices around it which increase the price of the robotic cell.
All of this makes the perfect candidate for a fast return on investment (ROI). Universal Robots are really well suited for machine tending, if you are interested in such robots, follow this link to learn more.
Since the robot you will be using needs to be versatile, the end-effector also needs to be flexible. In fact, you need to have a Gripper that can be able to carry the raw part, close the CNC machine door and remove the part form the device. All of this is performed with very few coding lines and a minimum customization. The best way to do it is to use an Adaptive Gripper like our very own Robotiq 2-Finger 85 Adaptive Gripper (LINK). This end-effector can do all the named operations above with the same fingertips and the same programming line. Since the Gripper can adapt to the geometry it is handling, you simply need to close the finger against the part and you are sure to grasp it. We also have an easy to install solution for Universal Robots, to learn more, follow this link.
What you need to know is that the robot cannot detect a part as you imagine it. In fact, you need to guide the robot bit. I highly recommend to have an ordering device either fix or mobile. In fact, having such devices are quite cheap and allow you to store a bunch of raw and/or finished parts for further work. There are various ways to do ordering trays, I saw some 3D printed devices and or machined plates. A conveyor with stepped motors allows to advance the parts one at a time and allows the robot to grasp at the exact same spot every time.
To enhance your production tightly you can use an advanced ERP system that will schedule your machine tightly and you will be able to program your robot consequently. In the same way you can prepare your steps in advance and enhance your turnover time and get back into production a lot faster.
At the end of the day, you will be able to increase your capabilities without outsourcing or buy another machine. Since a robot is cheaper than a machine and can work overnight and during the weekends, you get a fast ROI and your cash flow is not as much affected. Look at your different options to see if doing such a move is possible for you but remain conscious that your competitors will soon or later have a robot too!
Continue your research by reading Increasing CNC Productivity: More Machines, Outsourcing, or Robots?