Felix,iconoclastica wrote:I have a few suggestions that don't answer your needs, mainly for lack of precision, but they may give starting point for new thoughts:Do you have a method for knowing your "zero" independent of the value stored by the driver/your software? I've done some limited testing but nothing that can independently confirm the repeatability of my zero position to within 1 step (2.5um).
- Digital calipers contain linear encoders that can be tapped. Typically they are more precise than 0.1mm and may have reference to a an absolute zero. Right now I am trying to turn a pair of them into a position reference for the x-y stage on my microscope, but it's too early yet to report success.
- Likewise, when I dismantled a large format inkjet printer, I found two position encoders: a linear one for the print head position and a circular one for the paper transport. Both are transparent plastic (sheet/strip) with engraved markings that are optically read. I didn't salvage the reader component, but I suppose they can be found in any printer. Even if you don't use them for positioning, they still might come in useful for motion detection.
- The thought crossed my mind that e.g. a laser beam shot through a narrow hole (e.g. the needle of syringe, o a pair of apertures) would mark a pretty exact position (but maybe not enough...).
That's a great idea using the digital caliber if one could figure out how to mount it or remove the sensor. Keep us informed of your progress.
Here's a couple sites about reading these calibers.
https://pylin.com/2017/05/26/reading-di ... m-arduino/