We use a lead screw to push the plunger on a dispenser and we have a sensor to detect when the dispenser is empty. The problem is that we can’t position the sensor far enough down so it trips before the dispenser is fully empty. We are going to ditch the sensor and instead detect when the lead screw is fully extended. I can see several ways of doing this and was curious if you have a recommendation. Here are my current thoughts:
- Move to a certain current value (which will increase when the lead screw stops)
- Detect the failed motion (probably an amplifier fault)
- Look for position errors and trigger if it exceeds a configured value.
- … other ideas.