Calibrating Axis Straightness
- deepfritz7
- Offline
- New Member
-
Less
More
- Posts: 1
- Thank you received: 0
24 Nov 2013 03:34 #41136
by deepfritz7
Calibrating Axis Straightness was created by deepfritz7
Hi Folks!
I was wondering if LinuxCNC offers the capability to compensate for geometric errors of the machine axes?
For example on my mill: I posses the measurment equipment to measure the straightness of the 2m long X-Axis. I can measure the deviation from the ideal straight to the actual machine position. LinuxCNC could easily compensate this error using the Y-Axis, which is perpendicular to the X-Axis. Is that possible? And if not, how could i archive this ? I thought of programming a little tool for post-processing the G-Gode in order to compensate for the measured position errors, when LinuxCNC alone is not capable of doing this.
What do you guys think of this ?
I just know that on big professional cnc machines, the controllers allows to calibrate for spindle pitch errors, straightness errors, squareness errors and so on..
Greetings
I was wondering if LinuxCNC offers the capability to compensate for geometric errors of the machine axes?
For example on my mill: I posses the measurment equipment to measure the straightness of the 2m long X-Axis. I can measure the deviation from the ideal straight to the actual machine position. LinuxCNC could easily compensate this error using the Y-Axis, which is perpendicular to the X-Axis. Is that possible? And if not, how could i archive this ? I thought of programming a little tool for post-processing the G-Gode in order to compensate for the measured position errors, when LinuxCNC alone is not capable of doing this.
What do you guys think of this ?
I just know that on big professional cnc machines, the controllers allows to calibrate for spindle pitch errors, straightness errors, squareness errors and so on..
Greetings
Please Log in or Create an account to join the conversation.
24 Nov 2013 20:47 #41146
by Rick G
Replied by Rick G on topic Calibrating Axis Straightness
You might want to look here...
wiki.linuxcnc.org/cgi-bin/wiki.pl?Kinematics
Also search this forum a bit as it seems to me that this was discussed here not that long ago.
Rick G
wiki.linuxcnc.org/cgi-bin/wiki.pl?Kinematics
Also search this forum a bit as it seems to me that this was discussed here not that long ago.
Rick G
Please Log in or Create an account to join the conversation.
25 Nov 2013 07:15 #41152
by andypugh
Maybe....
LinuxCNC has built-in ways to compensate for screw-pitch errors, and there is a kinematics module that can compensate for out-of-square error.
But what you want to do is offset Y dependent on X and offset X dependent on Y.
I think you could so this with the lincurve HAL component. Pass X into the table and add the output to the Y value before passing it to the stepgen or servo.
If the corrections are significant then you might have problems with the f-error, so you should use the "offset" HAL component to add the offset to the motor position, then subtract it from the feedback position.
www.linuxcnc.org/docs/devel/html/man/man9/lincurve.9.html
www.linuxcnc.org/docs/html/man/man9/offset.9.html
Lincurve only exists in the development version of LinuxCNC, but it would be easy to copy the file across and compile/install it on your system using comp:
www.linuxcnc.org/docs/devel/html/hal/comp.html#_compiling
Replied by andypugh on topic Calibrating Axis Straightness
I was wondering if LinuxCNC offers the capability to compensate for geometric errors of the machine axes?
Maybe....
LinuxCNC has built-in ways to compensate for screw-pitch errors, and there is a kinematics module that can compensate for out-of-square error.
But what you want to do is offset Y dependent on X and offset X dependent on Y.
I think you could so this with the lincurve HAL component. Pass X into the table and add the output to the Y value before passing it to the stepgen or servo.
If the corrections are significant then you might have problems with the f-error, so you should use the "offset" HAL component to add the offset to the motor position, then subtract it from the feedback position.
www.linuxcnc.org/docs/devel/html/man/man9/lincurve.9.html
www.linuxcnc.org/docs/html/man/man9/offset.9.html
Lincurve only exists in the development version of LinuxCNC, but it would be easy to copy the file across and compile/install it on your system using comp:
www.linuxcnc.org/docs/devel/html/hal/comp.html#_compiling
The following user(s) said Thank You: finnstrom
Please Log in or Create an account to join the conversation.
25 Nov 2013 20:04 #41156
by Rick G
Replied by Rick G on topic Calibrating Axis Straightness
Might want to look at millkins...
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...y_XY_skew_correction
Rick G
wiki.linuxcnc.org/cgi-bin/wiki.pl?Contri...y_XY_skew_correction
Rick G
Please Log in or Create an account to join the conversation.
Time to create page: 0.148 seconds