Re: [CAD_CAM_EDM_DRO] Sargon encoder disassembly help

Bryan Mumford wrote:

> Thanks Jon. I can imagine doing this. I have found that, when
> unmounted, the encoder seems to work, but on the machine it tends to
> drop out in one place. I'm thinking it may be a matter of spacing,
> but I can't get the reader any tighter to the encoder because the
> mounting holes are snug. The read head is close to the encoder
> already. Does that make any sense?
>
> The failure is intermittent. It happened 6 months ago, then again two
> days ago. Right now it's working again. The plugs are secure.
>

Some of the cheaper scales have pretty mediocre schemes for controlling
the read head.
Such things as Teflon pads that set the distance between head and scale,
and music wire
to slide the head back and forth. If the music wire gets bent the wrong
way, like when the
head jams or you drive it too far to the end, it may not move the head
smoothly. If the
head twists instead of sliding perfectly straight all the time, that can
mess up the quadrature
relationship between the A and B sensors. So, it may ALL be due to a
kink in the wire or
strip that pushes the head back and forth, or possible a gash in the
sealing strips or something
like that.

A problem in one spot could ALSO be a bad cable, with a worn-out wire at
a certain spot.
Every time the machine moves to a certain spot, the bend of the cable is
just right to make that
wire go open.

Jon