Re: following error

[John Sheahan <jrsheahan-at-optushome.com.au>]

On Tue, Nov 13, 2001 at 01:33:59PM -0500, Ed Okerson wrote:
> 
> You are correct, I changed the INPUT_SCALE values to make my X and Y axis
> move 1 inch when commanded.  But isn't axis 2 the Z axis?  That is the way
> it is labeled in the GUI.  I have not made any changes to the Z axis scales
> as I don't actually have that part of the machine built yet!  I was simply
> trying to get the X-Y part moving before I continued any further.
> 
> Ed Okerson

Hi Ed
I used freqmod, but I had to adjust gain and error before that 
worked reasonably with no following error even before I 
adjusted scale (I *think*)

Perhaps the defaults could be better chosen. 

but as most everyone will need to adjust scales, fixing gain default
is no panacea.  

I think the way you are doing this makes sense, one step at a time.
terms you might want to look at include 

DEFAULT_VELOCITY,    as I'm metric, probably not useful to you at all here
MAX_VELOCITY 
DEFAULT_ACCELERATION, 
MAX_ACCELERATION
INPUT_SCALE,         whatever suits your units,     
OUTPUT_SCALE         same as input_scale
FERROR               I ended with 4 
MIN_FERROR           ** look carefully jere , I used 1
DEADBAND               if it chatters
P                  ( 10 seems a good start)
I D FF0 FF1 FF2    (set to zero for a while)


I just had to grow the motors on my router table, and the motor
control pcb's are due back from the design house in a couple of days.
Looking forward to that..

regards, john