Re: EMC and Angular Axis to run rotary table

Hi Damon

> will read 720 :) Be sure to open up the max and min limits
> so it wont error out. Also the following error variables

do you meant to say that i should set the max and min software limits?
by these variables??
MIN_LIMIT = -360.0
MAX_LIMIT = 360.0

ok lets assume my startup code of the machine is set to G21 (sets
position display and command interpretter in mm). I set input scale
parameter such that the A axis displays position in Degrees. what if
somebody runs a program in inches? Now the A axis degree display will
be scaled by a factor of 1/25.4 , isnt it? And Degree's display wont
stay in Degrees anymore...

Asim

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Damon" <damonfg@y...> wrote:
> Been a while since I set up a rotary axis in EMC...
>
> set type to linear, angular isn't implemented.
> units.... May as well stick with 0.0393xx for input
> scale, try 20. (20 steps = 1 degree)
>
> The A should read in degrees. Bear in mind it will
> not "wrap around" at 360. If you did 2 full turns it
> will read 720 :) Be sure to open up the max and min limits
> so it wont error out. Also the following error variables
> will have to get much wider, as it sees this axis as very
> coarse.
>
> In my limited experience, I found it to be *very* sensitive
> on coordinated moves. So much so that I would suggest only
> move the A axis, then have another line to move X/Y/Z.
>
> Hope this helps some.
> -Damon
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j.
> ..> wrote:
> >
> > > > now my 4th axis ini parameters are as follows:
> > > >
> > > > ; Fourth Axis
> > > > [AXIS_3]
> > > >
> > > > TYPE = ANGULAR
> > > > UNITS = 0.03937007874016
> > > > HOME = 0.000
> >
> >
> > How did you get the units ?
> > Assuming you are using degrees and not some other unit....
> >
> > If you have 360 degreees motion and the table turns 10 degrees
per
> > revolution ??
> >
> > a direct drive stepper on the shaft, no microstepping.
> >
> > 36 turns per revolution times 200 steps per revolution = 7,200
> steps
> > per 360 degrees or 0.05 degrees per step.
> >
> >
> > = = = = = = = = =
> >
> > Here is a simple list of angular numbers for my spreadsheet.
> >
> > 360 table units (circle)
> > 10 degrees per shaft revolution
> > 36 handle revolutions per one table rev.
> > 200 motor natural steps
> > 1 microsteps (1= no microsteps)
> > 200 actual; motor Step Per Rev
> > 7200 steps per table rotation
> > 360 table units (circle)
> > 20 steps per degreee
> > 0.05 degrees per step
> >
> > That comes out to 0.05 degrees per step.
> > everything else being equal, an using your number, I get that
you
> > would need
> >
> > 7.874015748 degrees per shaft revolution
> >
> > Hope this gives you some point of reference.
> >
> > Dave