Hello Guest it is May 24, 2019, 09:45:28 AM

Author Topic: More Rotary confusion  (Read 4037 times)

0 Members and 1 Guest are viewing this topic.

Offline Keith

*
  • *
  •  187 187
    • View Profile
More Rotary confusion
« on: January 05, 2006, 06:15:08 PM »
Okay,so,I'm ready to cut my cone.I first tested my rotary table for motor tuning and with everyone's help,with a G01 A15 my rotary goes to 15 degrees as promised.Now with the addition of the suggestions of Brian and some particular details for what I desire I modify this code and yes indeed,as I 'cut air',I see that cone a formin' BUT.......screech! It seems with the G91 incremental code stuck in there with each line progressing .5 ,my rotary does not go to half a degree but more like a quarter degree! Checked and rechecked motor tuning,did the G01 move again and that worked to position to the degree I entered.What up?-Keith

Art

*
Re: More Rotary confusion
« Reply #1 on: January 05, 2006, 06:52:45 PM »
Hi Keith:

 What line did it screw up on, and what was the DRO reading before and after the line?

Thanks
Art

Offline Keith

*
  • *
  •  187 187
    • View Profile
Re: More Rotary confusion
« Reply #2 on: January 05, 2006, 07:01:36 PM »
The code looks something like this
: G00 G90
X0.0000 Y0.0000
Z.1000
F25.0
G01 Z0.0000 X0.0000
M98 P0100 L360
G90 G00 Z.1000
M30

O0100
G90
F25 G01 X1.0000 Z-.75000
G91
A0.500
G90
F25
G01 X0.0000 Z0.0000
G91
A0.500
G90
M99
It runs through fine but instead of going half a degree it goes more like a quarter and the DRO reads correctly(Start with '0' and ends,after the first pass through "A0.500" it reads .5 on the money.
Re: More Rotary confusion
« Reply #3 on: January 06, 2006, 05:38:37 AM »
Try running this :
G00 A 0.0
G91
A180.0
M00
A-180.0
G90


This will tell if your axis is having a problem, you shoud see it move 1/2 a rev wait for a cycle start and go back to the start point.

Thank you
Brian
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com

Offline Keith

*
  • *
  •  187 187
    • View Profile
Re: More Rotary confusion
« Reply #4 on: January 06, 2006, 09:32:23 AM »
Thanks Brian,yes what happens with the code you posted is,I start my rotary table at 0 degrees,running the program it quite quickly is off by what looks like precisely 5 degrees (when I hit 180 on the DRO ,my rotary is at 175,when I go negative ,the DRO reads 0 and my rotary reads 355,back past the '0' on the rotary).Am I missing pulses? Keep in mind, when I say for instance, GO1 A15(starting my rotary at 0) it does indeed go to15 degrees.So if pulses are missed it's only in 'incrememtal positioning'.-Thanks,Keith
Re: More Rotary confusion
« Reply #5 on: January 06, 2006, 01:44:45 PM »
IT sounds like you should change your motor tune settings. Please back down you Max Vel and Accel. Keep doing this till you can run that little file.

Thank you
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com

Offline Keith

*
  • *
  •  187 187
    • View Profile
Re: More Rotary confusion
« Reply #6 on: January 07, 2006, 10:16:37 AM »
Okey.Dokey.Got it ! While it seems that the acceleration was the most offending parameter,I also believe that because I had the feedrate 'crawling' that might have been equally the culprit because it reminds me of pulse width modulating any motor project I've done,controlled by a microprocessor ; if I ask too much at one 'end' of the drivers ,the motor will not quite respond because of the time constant portion the motor introduces in it's reactance.
Thanks Brian.Me happy now :)