Stuart
Think about it. The linear will always be predictable. It moves
from the current position to new position. In linear absolute mode -180
is not the same as 180. If I were at between -180 and 180 for a move to
180 it would move CW, a move to -180 it would move CCW . If the
current position was above 180 it would move CCW for both. less than
-180, CW for both. In incremental mode it would move the same as if the
current position was between -180 and 180. It is true an axis that
rotates 360 degrees will appear to the operator as being in the same
position but mathematically they are not. Can't you get your
(0-359.999) performance by using the N MOD 360 operation which returns
the remainder of the number divided by 360. Only if I am thinking about
a position on a dial do these appear the same to me. I am certainly not
sure as how I would implement the behavior you describe. To me it is up
to the G-Code programmer or Post Processor to know that this is a
wrapped axis and to make the program efficient you can set the current
location to N MOD 360 with out a change in position. As a programmer or
the post processor I would like to know is how to change the current
linear position N to N MOD 360 without causing a physical move of the
machine, as my attempts with G10 L2 A 0 did not appear to have the
desired result.
Hubert
Stuart Stevenson wrote:
> Gentlemen,
> I can think of one scenario that the rotary (0-359.999) configuration will
> handle "better" than the linear (0 thru unlimited) configuration.
>
> On a 180 degree move you would give a command of B180 or B-180 (the same
> position). If the sign does not tell the machine which way to turn then how
> does the machine know which way to move the axis? Just as important, how
> does the operator know which way the machine is going to move? Also, how
> does the post handle the move? You would need an intermediate move to allow
> the machine and operator to determine the direction of motion. The post can
> be instructed by another commanded position or a direction vector for the
> tool motion.
>
> There are trade offs in all configurations. In my world, small it may be,
> the rotary configuration is clearer and more intuitive for the post, the
> operator and the machine.
>
> I am glad Henry Ford does not run the industry now. You could have any
> color Model T you wanted along is it was black. :)
>
>
------------------------------------------------------------------------------
Come build with us! The BlackBerry® Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay
ahead of the curve. Join us from November 9-12, 2009. Register now!
http://p.sf.net/sfu/devconf
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
