Re: Rambling hydraulic post that was: Multiple syncronized spindle question.

[Dncnorthwest1-at-aol.com]

When I started the post, I was thinking about adding scales to an existing tracer mill for feedback similar to the system on my Anilam Crusader ll control which used three scales for the axis and was accurate and repeatable to the accuracy of the scales, but has brush servo and tach for velocity control. The valves should be controlling flow to the requirement of the velocity needs of the machine. Without the feedback loop, you run into a battle. Ask anyone who ran BOSS series Bridgeports. They had open loop steppers, and before you pushed the button, you looked at the odometers ( digital counters) to see if it had returned to the right start position before you ran the next part. Adjust the gibs for wear, change the feedrate, let the cutter go dull, lean against the table while it was running and all the great things about CNC went away. 

Fred


In a message dated 9/28/2002 1:22:37 PM Pacific Daylight Time, bogmstr-at-infomagic.net writes:


> ----- Original Message -----
> From: "Jon Elson" <elson-at-pico-systems.com>
> To: "Multiple recipients of list" <emc-at-nist.gov>
> Sent: Friday, September 27, 2002 8:48 PM
> Subject: Re: Rambling hydraulic post that was: Multiple syncronized spindle
> question.
>
> snip
>
> >
> > He was talking about changing the servo loop's parameters as the hydraulic
> > oil
> > warmed up and became less viscous, I think.
> >
> > Jon
> >
> Indeed I was, but I am very glad to hear about more features of EMC.  It
> seems like it would be possible to sense the temperature of the oil in the
> tank, record how that affects the actual motion of the machine versus the
> commanded motion and possibly use a variable to scale the axis motion and
> spindle speed based upon the temperature and consequently the viscosity of
> the oil.  I don't know how difficult it would be to implement the IO for
> something like this, but it could make for an interesting project for
> someone more knowledgeable than myself.
>
> Regards,
>
> Howard Bailey