Re: Re: EMC stg2mod.o and problem with homing

Hi Asim

Glad that you got the one machine running. The transplant should work
fine here also as long as the revised code is from the same release or
date and you left the PC alone while it was compiling. I would tend to
doubt that your problem is caused by what you have done.

You've set INPUT_SCALE to 25000 so you should set DEADBAND to 0.000041 or
something like that. If you do not set a bit of deadband, your motors
will always hunt between adjacent pulses. If the acceleration is high,
this can lead you to try to reduce gain to help the axis to settle.
Since you do not mention any motor noise I am going to assume that this
axis is a bit to relaxed or there is a lot of drag in the mechanics of
the axis.

Rumor has it that the (I) and the (D) tuning components did not work quite
as advertised in releases earlier than 2.20. There has been a very
recent fix to some file or another that improved the use of these
variables in servo systems. You might want to update your distribution.

After setting proper deadband, what I would try next is to set the (I)
value to zero and double the (P) component. With this done, I'd grab
onto the ball screw someplace and attempt to turn it. You should not be
able to turn it much and you should hear power being poured into the
motor to resist. If the axis is fairly stiff, then I would begin to
command a bit of motion and see how the servo reacts. You might need to
reduce acceleration. If it is still lazy, you should increase (P) more.

Do you mean to set your maximum velocity to 300 IPM?

Ray

On Friday 03 October 2003 06:35 am, CAD_CAM_EDM_DRO@yahoogroups.com wrote:
> Message: 22
> Date: Fri, 03 Oct 2003 09:45:32 -0000
> From: "Asim Khan" <asimtec@...>
> Subject: Re: EMC stg2mod.o and problem with homing

<s>
> Please tell me what might be the problem with my setup? I already
> have another machine which had emc developer installed from the same
> cd but it is runing without any this homing offset problem. I had made
> changes in rhe newstg.c source file as directed by paul to enable
> index pulse latching. I had copied the newstgmod.o file from this OK
> system to the machine which is having this offset trouble.
<s>