Re: [CAD_CAM_EDM_DRO] Re: Out of Estop.. BUT

imranjawaid@... wrote:

> Finally i got rid of those jerky motion.I've looked in to manual for
> AC drives and there are vibration knobs on the drive.Finally tuned
> it.The motor is smooth.

Ah, yse, when you change ANYTHING, you need to retune. I certainly
know that.

>
> I also done the zero setting of my motor by joining COM and Pulse
> Input wires and adjusting Zero setting variable resistor on the drive.
>
> But when i connect it to the STG2 card it give me rotation.I checked
> tthe DAC0 input from STG2 card with multimeter and it gave me 0.01V.
> I also tried counter it with 0.085 V from EMC TESTING and it stopped
> moving.
> So how can i remove that 0.085V from STG2 DAC0 ?

There is a DC offset parameter in the EMC .ini file that offsets what
the program uses
as the zero, for exactly this problem. I don't NEED to use it, because
my servo
amps have differential inputs. I ASSUMED there would be some DC offsets
due
to ground loops between the computer and the servo rack, so my diff
input amps
subtract a ground reference signal from the velocity command signal, to
get as good
a zero as possible for the DAC output. If your amps have a single ended
input, what
I suggest about the offset parameter is the best you can do. But, if
your amps do
have a differential input, take the ground reference output from the STG
card and
tie it to that velocity minus input. The reason this is better is it
removes any drift
in the offset, which is a likely event.

> Another thing. The EMC can read encoder signals upto +/- 0.3 V , If i
> go higher like 0.4V it stops reading .

Are you saying that when you put more than .3 V into the servo amp's
velocity input,
EMC stops updating the position display? I don't really have an answer
for that.
It may have reached a travel limit, or the noise filtering may have
decided that you
have an impossible velocity. You might check the units and max velocity
numbers, and
otherwise make sure all constants in the .ini file are consistent.

> The servo gets hot when it moves on max rpm i.e 3000. at +/- 10v.Is
> this behaviour normal?

I know nothing about your servo amps. If you are not providing
sufficient cooling,
or if the motor is not designed for this speed, it may be producing
excessive
drag at that speed. I can't imagine a machine tool servo running that
fast in normal
operation. My X and Y axis motors RARELY, if ever, get over 1000 RPM.

Jon