Re: EMC stg2mod.o and problem with homing

I start getting too much thundering noise if i increase the P gain.
I had heard that P gain is set to about 60% of the P gain where you
start getting sustaind oscilations.
I also have experienced that the I gain has no impact in EMC tunning.
There is been a rumor around that I parameter has some bug in older
emc releases. May be the version (BDI-EMC V2.16) i am using has the
same bug. Thats why i dont see any effect of this parameter.

However i can see the effect of D gain. But D gain tends to increase
instability. Even for smaller values of D gain, axes tend to generate
noise.
VFF seems to be a great parameter when it comes to reducing following
error.

Asim




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Leslie M. Watts"
<leswatts@a...> wrote:

> Great Asim!
>
> I had not considered that your servo amps might have had an offset.
> With low P and I gain this could cause the problem you mentioned.
>
> Leslie M.Watts
> L M Watts Furniture
> Tiger Georgia USA
> (706) 212-0242
> http://www.lmwatts.com
> Engineering page:
> http://www.lmwatts.com/shop.html
> CNC surplus for sale:
> http://www.lmwatts.com/forsale.html
> CNC carved signs:
> http://www.lmwatts.com/signwp.html
>
>
>
>
> -----Original Message-----
> From: Asim Khan [mailto:asimtec@y...]
> Sent: Thursday, October 16, 2003 11:13 AM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Re: EMC stg2mod.o and problem with homing
>
>
> Hi Jon, Les, Paul, Ray and all other group members!
> Finally i was able to fix this home offset problem. I set
> the voltage offset values for each axis to stop motion when machine
> is in estop_reset condition
> following are ini parameters now:
>
> for x axis
> OUTPUT_SCALE = 1.000 0.054
> previously it was
> OUTPUT_SCALE = 1.000 0.000
>
> for y axis
> OUTPUT_SCALE = 1.000 0.080
> previously it was
> OUTPUT_SCALE = 1.000 0.000
>
> for z axis
> OUTPUT_SCALE = 1.000 0.0732
> previously it was
> OUTPUT_SCALE = 1.000 0.000
>
> now when i home each axis the machine cordinates display
> 0.000 mm ± 0.001 mm
>
> I am thankfull for everyone who contributed in my post
> regards
>
> Asim