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Mach3 XML and Stepconfig issues.
24 Apr 2017 14:02 #91964
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
Todd, so am I as it has been working OK with Mach for many years.
I am more or less planning to replace my home-built BoB to a more modern one and go with PWM to 0-10V conversion if no remedy is possible for this.
In the pipeline there is a MESA setup, have all boards and new AC servos for X/Z and also a 3kW AC servo for spindle but I would like to see my basic parts to get working. Going MESA is no more Mach and I'm a bit uncertain about the lathe GUI in LCNC and in general what I can do in Mach3.
That is why I need to have both working in parallell to learn LCNC and get comfortable with it.
I am more or less planning to replace my home-built BoB to a more modern one and go with PWM to 0-10V conversion if no remedy is possible for this.
In the pipeline there is a MESA setup, have all boards and new AC servos for X/Z and also a 3kW AC servo for spindle but I would like to see my basic parts to get working. Going MESA is no more Mach and I'm a bit uncertain about the lathe GUI in LCNC and in general what I can do in Mach3.
That is why I need to have both working in parallell to learn LCNC and get comfortable with it.
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24 Apr 2017 14:30 #91965
by andypugh
Replied by andypugh on topic Mach3 XML and Stepconfig issues.
I don't think we can read too much into the halscope plot, as the video shows that it is sampling in the servo-thread at 1kHz rather than in the base thread. The apparent pattern in the output is probably actually "aliasing".
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24 Apr 2017 14:35 #91966
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
Please tell me what to do and setup halscope properly.
Cheers
Bengt
Cheers
Bengt
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24 Apr 2017 14:42 #91968
by andypugh
Replied by andypugh on topic Mach3 XML and Stepconfig issues.
It might be interesting to halscope stepgen.N.frequency
That would indicate if LinuxCNC thinks that it is doing the right thing.
To run halscope sampling in the base-thread, click the button that indicates the sampling rate.
That would indicate if LinuxCNC thinks that it is doing the right thing.
To run halscope sampling in the base-thread, click the button that indicates the sampling rate.
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24 Apr 2017 14:56 - 24 Apr 2017 14:57 #91970
by andypugh
Replied by andypugh on topic Mach3 XML and Stepconfig issues.
Reading the LM2907 data sheet, I am wondering if it is struggling with the duty-cycle of the stepgen output being nothing like 50%?
e2e.ti.com/support/amplifiers/etc_amplif...linear/f/18/t/375205 confirms that 50% duty-cycle is what is expected.
I _think_ that if you set the stepgen to quadrature mode then the A-phase will then have a 50% duty cycle. The drawback with this scheme is that the stepgen DIR pin is then no use at all for setting the spindle direction, and this output would need to be generated a different way.
So, try commenting-out the DIR connection to the parport, and edit the loadrt line
e2e.ti.com/support/amplifiers/etc_amplif...linear/f/18/t/375205 confirms that 50% duty-cycle is what is expected.
I _think_ that if you set the stepgen to quadrature mode then the A-phase will then have a 50% duty cycle. The drawback with this scheme is that the stepgen DIR pin is then no use at all for setting the spindle direction, and this output would need to be generated a different way.
So, try commenting-out the DIR connection to the parport, and edit the loadrt line
loadrt stepgen ctrl_type=p,p,v step_type=0,0,2
Last edit: 24 Apr 2017 14:57 by andypugh.
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24 Apr 2017 15:01 #91971
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
I hope I´ve got it right.
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24 Apr 2017 16:05 - 24 Apr 2017 16:06 #91973
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
Got email message with your answer but it is not showing up here.
Looking at the plots short pulse comes steady but step length is very short, so I wonder how it works OK in Mach?
Will try to apply Quadrature and report what happens.
Looking at the plots short pulse comes steady but step length is very short, so I wonder how it works OK in Mach?
Will try to apply Quadrature and report what happens.
Last edit: 24 Apr 2017 16:06 by tecno.
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24 Apr 2017 16:26 - 24 Apr 2017 16:27 #91975
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
Halconfig shows flashing yellow ch A
Halscope nothing
Halscope nothing
Last edit: 24 Apr 2017 16:27 by tecno.
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24 Apr 2017 16:42 #91976
by tecno
Replied by tecno on topic Mach3 XML and Stepconfig issues.
Had to comment out several lines in hal to have lcnc starting
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24 Apr 2017 17:02 #91980
by Todd Zuercher
Replied by Todd Zuercher on topic Mach3 XML and Stepconfig issues.
What does it look like with the spindle speed set to its fastest speed?
Try adjusting stepgen.2.steplen. Try setting it to 2500000 (that would make the step length half the frequency of your top speed.)
Try adjusting stepgen.2.steplen. Try setting it to 2500000 (that would make the step length half the frequency of your top speed.)
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