Re: Encoders on the opposite end of the shaft

Thanks, Brad, re the lore on your Tape 'O' Matic. If it's good enough
for P&W it's good enough for me. Could you take a look at the
connection between the encoder and the screw? I assume the encoder(s)
is rigidly mounted to the underside of the table and coupled to the
screw with some sort of flexible coupling (what kind?)--or maybe the
other way around--rigidly coupled to the screw and mounted to the
table on rubber. How did the P&W guys do it?

Thanks again.

--Jack


--- In CAD_CAM_EDM_DRO@egroups.com, "Heuver, Brad (B.R.)"
<bheuver@f...> wrote:

> My old P&W Tape'O'Matic is set up with the motors coupled 1:1

with

> the ball screws with cogged tooth belts. The tach is on the

motor. The

> encoder is on the opposite end of the shaft than the drive cog.

Although

> this beast has yet to run for me, it was obviously running this way

before

> it went brain dead. It's very likely that the lash/flex in the

cogged belt

> was much more than the twist of the ball screw, thereby making the

decision

> as to what end of the shaft to sense a moot point. This design

might be

> easier to implement than a rigidly coupled motor.
>
> Brad