Re: My Logan Clunker

Jack,

Never heard of exactly what you're describing on a lathe. There is
something along those same lines for most commercial lathe and mill
controls, though. The ball screws are calibrated and a table of the
screw pitch deviations over their length is entered. When the
machine makes a move the table is checked versus current position and
position corrections are made to compensate for minute errors in the
ball screw pitch. This is used in ultra precision machines. This
same type setup could be used on your lathe by calibrating the bed
versus carriage position. This is fun to to theorize about, but your
problem is finding control software that'll do these things.

A much easier way is to do what the rest of us do. Compensate for
the irregular bed in your Gcode programs. In other words, if the
lathe tends to turn a taper, program a taper in the opposite
direction and the part will come out straight.

Doug

--- In CAD_CAM_EDM_DRO@y..., jmw@c... wrote:
> If I were to convert my old 12 x 36 Logan to CNC, is it reasonable
to
> expect that the system could correct for the machine's worn ways?
>
> Presumably the system 1) would know the carriage position along the
> long axis and 2) could be given a map of the way wear. While the
> machine ran, a demon in the cross slide could be checking 1) and 2)
> and making little in and out adjustments to correct for the wear.
> Maybe this could be relatively transparent to the user, and maybe
the
> Logan could turn out a cylinder again?
>
> If this is a standard feature in CNC lathe systems, pls excuse the
> bandwidth--I did check the archives.
>
> Thanks in advance.
>
> --Jack