Re: [CAD_CAM_EDM_DRO] replacing servo motor help >signal phase

Owen wrote:

>So to anyone that has followed this thread.
>
>I did get a technician to take a look at the motor and he told me [I called
>him back to explain in english for me] that "The signals coming out of the
>encoder are supposed to be 90 degrees out of phase but your are coming out
>180 degrees out of phase. I can't see a way to adjust that."
>
>Do this sound correct?
>
>
>

If the alignment between the encoder and the disc has been disturbed,
this is completely possible, and will totally screw up anything trying to
interpret the encoder signal. You might look closely for some
"glyptal" on the screws that hold the encoder read head in place.
Glyptal is the brownish glue that is used to seal alignment screws
in place once the alignment is set right. It may show that the head has
been bumped out of place, and you may even be able to gently shove
it back into place. If this fixes it, you can then put a tiny speck of
superglue over the glyptal to hold it in place. Depending on how the
encoder is built, and how it is attached to the motor, there may be bent
metal brackets instead of a bumped plastic read head, and it could be
pretty tricky to realign that.

If this is a differential encoder, then there is supposed to be a signal
180 degrees out of phase with every signal (they will often be labeled
A, A(bar), B, B(bar) to indicate the complement signals. The (bar)
means a bar (vinculum) over the letter.) If that is what the tech
is complaining about, you need a better tech. But, comparing A to B,
there should still be the 90 degree phase shift.

Jon