Re: Plasma cutter

[Ray Henry <rehenry-at-up.net>]

Hi Luc

Thirty meters per minute is rather fast. (1200 ipm)  I may have to come 
over and watch this machine work!  

For the two meter axis use something like this.  It assumes a home in the 
center.

TYPE =                          LINEAR
UNITS=                      1
MAX_VELOCITY =                  500
DEADBAND = 0.05
CYCLE_TIME =                    0.001
INPUT_SCALE =                   20    0
OUTPUT_SCALE = 20.000 0.000
MIN_LIMIT =                     -1000
MAX_LIMIT =                     1000
FERROR = 25.400
MIN_FERROR = 0.2540

The trick here may be the ferror and min ferror.  For some reason these 
do not scale to the type of unit used.  

The other part that you will need to take great care with is the 
acceleration in [TRAJ]

AXES =                  3
LINEAR_UNITS =          1
CYCLE_TIME =            0.01
DEFAULT_VELOCITY =	10
MAX_VELOCITY =          500
DEFAULT_ACCELERATION =  50
MAX_ACCELERATION =      100

You may have to work with these numbers a bunch to keep your steppers 
from skipping.  It will be much worse if you have much mass that you are 
moving.

Hope this helps

Ray



On Sunday 23 February 2003 03:50 pm, you wrote:
> Hi list,
>
> I want to use EMC to control a plasmacutter.
> As the XY table measures 2 X 3 meters, I want to make G0 movements with
> a speed of 500 mm/sec. I will use:
>     200 step/rev steppermotors.
>     5KHz step rate =>  5000pls /sec
>                                  -------------------  = 25 revolutions
> /sec 200 puls/rev
>
>     500 mm/sec
>     ------------------    20pulses /mm
>     25 rev/sec
>
> In my ini file I set both SCALES on 20, UNITS = 1
>
> I always get a following error.
>
>
>
> Is it inpossible to reach such a speed ? Do I have to adjust settings ?
>
> Thanks in advance.