Machine Tending: Starting Point
Posted on Nov 15, 2017 7:00 AM. 3 min read time
Chances are, you are probably in one of these 2 situations.
- You have a CNC machine up and running and you simply want to install a robot in front.
- Looking for a way to optimize your production, your are planning to purchase a brand new CNC machine and a robot to achieve your goal.
Each of these situations will have a different impact on your machine tending integration.First, check this video to see how collaborative robots can help with Machine Tending.
Here are the main things to consider before making a decision:
As you are going to load and unload parts on an unattended machine you will want to use a vise or a chuck that will open and close automatically. Most automated vises are air powered. This means you will need a small Programmable Logical Controller (PLC) or some way to send signals to the vise indicting when it’s time to open or close.
Actuated Door or Not?
There will come a time in your integration where you will have to decide if you need an automated door or not on your CNC machine. If you are buying a brand new machine, we recomment this option. The costs are generally worth it. If you are looking to automate machine tending on an existing CNC, you may not have the option to open and close the machine door automatically. We have seen a lot of integration projects where the robot was actually closing the door of the CNC machine and it works perfectly.
Here are some real life examples of integrations with different types of door management.
Example of a door operated by the robot. In this case, the robot was added to the existing machine. There was no actuation system on the door, so the user decided to simply replace the operator’s action by the robot.
Example of an actuated door. In this second case, the machine was bought in conjunction with a robot. In order to ease the integration, the company chose a CNC machine with an actuated door.
I/Os & Communication
There are a lot of different signals that you can get from a CNC machine. Likewise, you can get a lot of information out of your robot. In order to make these 2 devices talk together, you need to have a communication port available to connect one with the other. For machine tending specific applications, a total of 6 I/Os are needed.
To have a better idea of what the difference is between digital and analog signals, read this discussion on DoF.
Measuring Parts With a Probe
If the location of a part is extremely important for your milling machine you can use the probe in your machine to set the position of the raw piece that has just been put in the machine. In fact, if your raw material is trimmed with very little surplus material available to work with and you need a super precise first cut, you may want to know the exact position of the raw part. Having the exact position of the raw part will eliminate your chance of running an empty machine and reduce your chance of making a wrong first cut.