[miro]

[quote name='TheChris' timestamp='1312957220' post='10564']

Hmmm.. I haven't done the math, but during my study at polytechnical colleague we had a shop that could print us layer masks for an 35µm SU-8 process. The colleague did me a favor 4 years ago by ordering 180lpi custom encoder masks for me at that shop which I needed for certain optical position sensors.



What would be the resolution you need, either given in lines perinch oder millimeter line distance?



Christian

[/quote]



The problem with encoder is not resolution. We have novadays rotary encoders with 37 bits/revolution. However the accuracy is still counting in percents % /e.g. 0.01...1%typical value /. When you look at high end encoders from Heindenhain you will come back to Ziess. They use the Zeiss high quality glass for their encoders.

However I woud say that there are not extreme expansive – e.g price of 2000..3000Euro for such encoder or target is still acceptrable???



What will be more exaensive is

1. Keep clean target

2. ALignment of Target

3. Alignment of camera

4. Precisision foucus

5. Environmental disturrbanceses. E.g trilling

======================

I have few ideas. But all of them are very expensive.

If you have some ideas how to solve all 5 issues above please let me/us know.

I'm interested of such setup too