I need to find a high resolution encoder to try some stuff out for my project. The problem I have is the ones I find are either to expensive or to tall to fit in my case.
Been thinking about making my own with photointerruptors and a code disc however it would still be hard to get the resolution I’m after.
I would like to achieve at least 1000+ klicks per revolution and if possible double that. I remember that extraclassig used the photointerruptors from an old exponent a while back and made his own code disc. Does anyone know how that turned out? Or what resolution he ended up with.
I’m a little stuck on this one, so any advice is greatly appreciated.
Been thinking about a multi level code disc, perhaps even one with absolute position to help avoiding bad readings. Let me know what you think. Could this work or is it a silly idea?
you can easily increase the resolution of an optical encoder by adding more sensors to the circle:
i’ll explain it in an easy example.
say you have a resolution of 2 klicks by now with 2 sensors (you need 2 to get the direction of the turn). if you add 2 sensors 90 degrees apart from the existing ones you can get 2 klicks per turn.
this also should work for higher resolutions than 2 klicks
be aware that the placement of the sensors has to be extremely accurate if you want some seroius output!
That should work. Would be hard to get it properly calibrated though!
Will try it once I get to that stage of the project. If it’s to hard, I might get a code disc laser cut with a slight offset between each layer to get the same effect with the sensors mounted on a straight line from the center and outwards.
Thanks for your input! This could prove very useful!
This app gives you several variables to play with, including resolution and absolute / relative.
The great thing about using gray code is that you aren’t limited by how fine you can make your photointerrupters. If you’re creating a platter with injection molding, rapid prototyping equipment, etc, you’re going to be hard pressed to get “teeth” finer than 2-3mm. On a small platter this can be limiting. Yes, you can use multiple sensors and quadrature, but this setup can also be fiddly to DIY.
Great stuff!
Thanks again for sharing!
If I manage to make any progress I’ll post pictures for sure. This encoder project is still a couple of months away though. Going to finnish my MIDI mixer first.
