RE: How does this stepper speed sound???

["Pete Cook" <pete.cook-at-alltracorp.com>]

A couple of questions back -
WHat kind of linkage do you have - Acme threads, small ball screws??? and
the diameter of them.

How heavy are the slides?

What kind of accel values are you using?

You are probably working with the limits of you drives - higher speeds
probably require servos instaed of steppers.

Pete


>
> Hello all,
>
> OK, now that I have emc running my homemade mini-mill with steppermod,
> I'm wondering how much (more) effort I should put into trying to get
> freqmod going.  As a number of others seem to have done, I've
> tried many
> combinations of PID values to no avail.  (following errors abound)
> Here's the setup and the results I'm getting now:
>
> BDI 2.0
> Pentium III 333MHz/128 Mb RAM
> 23 Frame, 80-100 (or so) oz-in. motors  (a guess, they're not
> labelled!!)
> 1.0 Amp drive current to motors
>
> I'm currently able to move the table (in X,Y or Z) at a maximum of 40
> inches/min.
> Any faster and things get squirrelly quick.
>
> As a complete CNC novice I have no idea if this speed is
> typical or if I
> should expect better!   Somewhere in the deep recesses of my brain I
> seem to recall seeing a small cnc machine moving a whole lot
> faster than
> this.   By the way, I am running a driver made by the
> Superior Electric
> Co. which can deliver a maximum of  2A to the motors. (It's set at 1A
> max now, my guess as to the capacity of the motors.  They get pretty
> warm after a bit of use...)
>
> So, what do you think?  Will freqmod give me more speed?  Smoother
> motion?  Or should I just go with what I have so far?   If
> anyone has a
> similar setup and has freqmod running their steppers, could you please
> clue me in to your PID settings?
> (Please don't all email at one time!!!!!)
>
> thanks,
> Patrick
>
>
> --
> .
>
>