So, this may be really basic. Actually, I hope it is. But my google-fu appears weak at the moment.
What I’m trying to accomplish is reading a differential servo signal (well, 2 signals since they’re in quadrature) without disrupting where they’re currently going. The signals in question are being generated and read by a haas st-20y turning center). I need the haas control to not lose the axis.
This is for a fun little project (double crowned helical gear cutting). I need the “transverse” (z axis) position of the hob. The double crowning is achieved by varying the synchronization between the “work gear” and the hob based on the transverse position. The haas control doesn’t have this ability, so my plan is to add an encoder to the spindle if the c axis encoder isn’t active when in “cutting mode”, or read the c axis encoder, bolt a new spindle/axis to the turret with the rotational position controlled by a pid loop on a micro controller I’ll add, and then, read the z axis position from the machine. The haas control will be in charge of the spindle motor and the z axis like normal.
My first thought was just to y the connections...but many encoders seem to be able to source very little current, so I’m not sure if this is safe. My initial thought was to use a very very very high input impedance opamp...could split the signal and decode it in one go. This just seems way too simple. A corralary to Murphy’s law states that nothing is ever simple. Therefore, I find this to be likely incorrect.