Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: comet on November 21, 2012, 05:41:22 AM

Title: bizarre feed rate dro behaviour
Post by: comet on November 21, 2012, 05:41:22 AM
My set up seems to have developed a glitch.
in motor tunings the speeds are correct,Ive checked that with motor rpm /measurements.
But the DRO's on the home page are approx 32% too fast.
this is something that has happened recently,ive tried reinstalling but that hasnt worked.
 any Ideas?
  Tony
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 21, 2012, 07:04:59 AM
If the DRO you are looking at is the units per min one and you are doing a G0 moving 2 or more axis  then that is normal. What you are looking at is the blended speed so although the X and Y are moving at a certain rate they are moving diagonally so the actual tools path is much faster. If you are doing a programmed move such as a G1 then Mach should keep very close to the commanded feedrate defined by the F word.

Hood
Title: Re: bizarre feed rate dro behaviour
Post by: comet on November 21, 2012, 07:58:55 AM
no its a one axis straight line movement and all axis are effected.
 tony
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 21, 2012, 08:03:51 AM
Attach your xml and I will see if I can replicate here.
Hood
Title: Re: bizarre feed rate dro behaviour
Post by: comet on November 21, 2012, 08:32:19 AM
try that
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 21, 2012, 11:10:51 AM
All seems fine here, when I jog with the shift the DRO shows very close to the 2500 you have for your rapid. When I command a feed move it again shows close.
Can you take a look at the Frequency on the Diagnostics page and see what it says..
Hood
Title: Re: bizarre feed rate dro behaviour
Post by: comet on November 21, 2012, 11:20:27 AM
will do,when i get home. could it be anything to do with me messing with the cpu/memory speed on the motherboard? thinking about it,itseems that it all started playing up when I lost my bios settings.
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 21, 2012, 11:33:03 AM
Yes it could well do, I am guessing the frequency will be showing as 45KHz or so.
Hood
Title: Re: bizarre feed rate dro behaviour
Post by: comet on November 21, 2012, 04:25:14 PM
showing 41khtz the program is set at 35,have reloaded bios settings and no differance
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 21, 2012, 04:30:00 PM
I suspected it would be something like that. Seems your computer doesnt like the 35KHz, try setting the kernel  to 45KHz and restart Mach and see how it behaves.
Hood
Title: Re: bizarre feed rate dro behaviour
Post by: comet on November 22, 2012, 04:01:04 PM
Well I ended up having to go at 60k kernal speed to get it to sync. surprised the computer would run it as its a good 10 years old!
Title: Re: bizarre feed rate dro behaviour
Post by: Hood on November 22, 2012, 04:35:07 PM
Hopefully that is you sorted :)
Hood