Hello! I'm having trouble with a new project where I need to count coil springs that are produced by a machine. The springs are throw on a ramp after the machine is finished and then they fall on a box that is right under the ramp. See the image for details.
The problem looks simple at first glance, but it gets harder after some particularities. The springs sizes varies for 1cm to 25cm. The inner diameter varies between 0.5cm to 1cm. The springs jump a lot, so they fall in different places.
I already tried to use a light beam sensor, but as I said, because the springs jump and are very thin the sensor miss some of them.
Another solution was to create a plate above the box where they fall so the spring would fall at the plate first. I attached a piezo sensor to detect the vibration of the plate. This works for the heavier springs but for the smaller and lighter ones not.
I'm looking for counting the actual spring. Putting an end switch on the machine is out of the question.
Was wondering if someone could help me to advance on this problem. I don't have the budget to buy some fancy sensors so I'm trying cheaper alternatives.
The cutting element is like a knife. It opens and when the spring is finished it comes back to actually cut the wire. My main problem is that the cutting mechanism keeps working even if there is no wire (wire fault).
The springs varies a lot. The distance between every coil can be bigger or smaller, it depends on the model. The test that I did with the light beam showed me that it can pretty difficult to measure them with this type of technology.
They are all made of metal, which conducts a current. Maybe that can be used in some way?
Like if there were probes across the entry to the box which could be connected for an instant by the passing spring. Perhaps metal doors across the entrance to the box which do not quite touch in the middle. A spring touching them would pass a small current which would trigger a circuit to open the doors and allow the spring to fall into the box.
