I would like to move a rubber wedge up and down in order to measure a distance. The wedge is about half the size of a pen and must measure distances of up 5 mm wide with accuracy better than +/- 0.1 mm. It is moved down until it can go now further and then, based on the vertical distance moved, the horizontal displacement can be computed and outputted. That's it. What I am unsure about is what kind of mechanics to hook up to the arduino to do the moving, the stopping and, most of all, do it very accurately.
You could use a stepper motor and a threaded rod. Depending on the gearing that would be very accurate.
The problem as I see it is how do you know when the wedge is touching? I can think of no way to do this short of measuring the current required to step the motor and this would be very inaccurate.
Thanks, Rob. The material whose gap needs measuring is sheet metal. The material of the wedge is arbitrary, it could be metal as well. Indeed seeing when to stop is a major issue. There should be no damage to the object from over-pushing ...
The material whose gap needs measuring is sheet metal. The material of the wedge is arbitrary, it could be metal as well.
The reason I asked is that if everything is metal maybe a good way to detect a touch is with conductivity. That wouldn't place any force on the things being measured.