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need help configuring LinuxCNC
15 Feb 2013 08:25 - 15 Feb 2013 08:31 #30080
by rebeltaz
need help configuring LinuxCNC was created by rebeltaz
I built my own CNC machine from the book at buildyourcnc.com/book.aspx and up until now, I have been trying to use Mach3. The z-axis keeps dropping, and since I have checked EVERYthing else, am thought I'd give LinuxCNC a try - I prefer Ubuntu Linux anyway.
I managed to figure the configuration out enough so that I could get the machine to move, but the distance it moves is WAY wrong. Can someone please help me figure this out.
I am using a TB6560 3-axis controller with KL23H286-20-8B 425 oz stepper motors. The leadscrew is a 1/2" 10TPI threaded rod from any hardware store. I am attaching the datasheet for the stepper motor and the manual for the controller as well as the .ini file created by the StepConfWizard.
Here are the parameters as entered into Mach3:
Port Setup
Port #1: Address 0x378
Kernel Speed: 35000Hz
Motor Tuning
X-, Y- and Z-Axis
Motor Output
X-axis: Step Pin #1, Dir Pin # 7, Dir Active Low
Y-axis: Step Pin #8, Dir Pin # 3, Dir Active Low
Z-axis: Step Pin #5, Dir Pin # 4, Dir Active High
Output Signals
Enable 1: Pin #14, Active High
Enable 2: Pin #2, Active High
Enable 3: Pin #6, Active High
Output 1: Pin #9, Active High
Input Signals
X++: Pin #10, Active High
X--: Pin #10, Active High
X home: Pin #10, Active High
Y++: Pin #11, Active High
Y--: Pin #11, Active High
Y home: Pin #11, Active High
Z++: Pin #12, Active Low
Y--: Pin #12, Active Low
Z home: Pin #12, Active Low
E Stop: Pin #13, Active Low
I hope this is enough information to go on. I will appreciate ANY help at all! Thanks...
EDIT: I cannot get the PDF for the controller to upload so I uploaded it to my server:
www.robotsandcomputers.com/CNC-build/TB6560_3Axis_Driver.pdf
I managed to figure the configuration out enough so that I could get the machine to move, but the distance it moves is WAY wrong. Can someone please help me figure this out.
I am using a TB6560 3-axis controller with KL23H286-20-8B 425 oz stepper motors. The leadscrew is a 1/2" 10TPI threaded rod from any hardware store. I am attaching the datasheet for the stepper motor and the manual for the controller as well as the .ini file created by the StepConfWizard.
Here are the parameters as entered into Mach3:
Port Setup
Port #1: Address 0x378
Kernel Speed: 35000Hz
Motor Tuning
X-, Y- and Z-Axis
- Steps Per - 41600
- Velocity - 10
- Acceleration - 7
- Step Pulse - 5
- Dir Pulse - 5
Motor Output
X-axis: Step Pin #1, Dir Pin # 7, Dir Active Low
Y-axis: Step Pin #8, Dir Pin # 3, Dir Active Low
Z-axis: Step Pin #5, Dir Pin # 4, Dir Active High
Output Signals
Enable 1: Pin #14, Active High
Enable 2: Pin #2, Active High
Enable 3: Pin #6, Active High
Output 1: Pin #9, Active High
Input Signals
X++: Pin #10, Active High
X--: Pin #10, Active High
X home: Pin #10, Active High
Y++: Pin #11, Active High
Y--: Pin #11, Active High
Y home: Pin #11, Active High
Z++: Pin #12, Active Low
Y--: Pin #12, Active Low
Z home: Pin #12, Active Low
E Stop: Pin #13, Active Low
I hope this is enough information to go on. I will appreciate ANY help at all! Thanks...
EDIT: I cannot get the PDF for the controller to upload so I uploaded it to my server:
www.robotsandcomputers.com/CNC-build/TB6560_3Axis_Driver.pdf
Last edit: 15 Feb 2013 08:31 by rebeltaz.
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15 Feb 2013 15:06 - 15 Feb 2013 16:20 #30094
by ArcEye
Replied by ArcEye on topic need help configuring LinuxCNC
Hi
You will have to be specific, it will be related to the SCALE= figure in your .ini file
Your micro-stepping, gearing, thread pitch all comes into this calculation, which is the number of step pulses per machine unit, in your case presumably 1 inch
linuxcnc.org/docs/2.5/html/config/ini_co...d_sub_axis_section_a
So for instance, if you move 1.5" when commanding 1", your scale figure is 66% of what it should be (move 150%), etc etc.
regards
.........................but the distance it moves is WAY wrong
You will have to be specific, it will be related to the SCALE= figure in your .ini file
Your micro-stepping, gearing, thread pitch all comes into this calculation, which is the number of step pulses per machine unit, in your case presumably 1 inch
linuxcnc.org/docs/2.5/html/config/ini_co...d_sub_axis_section_a
So for instance, if you move 1.5" when commanding 1", your scale figure is 66% of what it should be (move 150%), etc etc.
regards
Last edit: 15 Feb 2013 16:20 by ArcEye.
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15 Feb 2013 15:18 #30095
by rebeltaz
Replied by rebeltaz on topic need help configuring LinuxCNC
I'm sorry. I told it to move the Z-axis 2", but it only moved it like .178" using the default driver timing settings - I couldn't figure out HOW to determine them based on the documentation that I had. I did try different presets and, using one of them (I forget which right off hand), I did get the axis to move .48" when told to move 2"... Not sure if that helps...
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15 Feb 2013 16:24 - 15 Feb 2013 16:32 #30097
by ArcEye
Replied by ArcEye on topic need help configuring LinuxCNC
You need to look at the docs and find out what the stepping presets are
A stepper takes 200 pulses of 1.8deg movs for one revolution, if you are half stepping for instance that becomes 400
Then your 10 tpi thread will take 10 revs to move 1", so that is SCALE=4000 (assuming there is not some other gearing)
Your scale is 41,000, so I suggest therein lies your problem
The formula is in the link I gave
regards
PS
If you divide 2 by .178 and then divide 41,000 by that figure you get near 4000 but a bit out from it
If you divide 2 by .48 and then divide 41,000 by that figure you get near 1000 but a bit out from it
You may find that your 10tpi screw is far from accurately pitched and you will have to fiddle with the theoretical figures to achieve the required travel, but this may not be accurate throughout its length
The ultimate answer is probably a ballscrew.
A stepper takes 200 pulses of 1.8deg movs for one revolution, if you are half stepping for instance that becomes 400
Then your 10 tpi thread will take 10 revs to move 1", so that is SCALE=4000 (assuming there is not some other gearing)
Your scale is 41,000, so I suggest therein lies your problem
The formula is in the link I gave
regards
PS
If you divide 2 by .178 and then divide 41,000 by that figure you get near 4000 but a bit out from it
If you divide 2 by .48 and then divide 41,000 by that figure you get near 1000 but a bit out from it
You may find that your 10tpi screw is far from accurately pitched and you will have to fiddle with the theoretical figures to achieve the required travel, but this may not be accurate throughout its length
The ultimate answer is probably a ballscrew.
Last edit: 15 Feb 2013 16:32 by ArcEye.
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15 Feb 2013 21:20 #30113
by andypugh
Replied by andypugh on topic need help configuring LinuxCNC
Out by a factor of 4, so I would guess that your drive is set to 4x microstepping and you need to multiply the SCALE in the INI by a factor of 4 (or do it in Stepconf)I did get the axis to move .48" when told to move 2"... Not sure if that helps...
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16 Feb 2013 02:09 #30137
by rebeltaz
Replied by rebeltaz on topic need help configuring LinuxCNC
Well, I have the controller set to 1/8 microstepping (I don't know why... ) but I did tell StepConf that Drive Microstepping was 8.0. Is that not correct?
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16 Feb 2013 02:14 #30138
by andypugh
![:-) :-)](/media/kunena/emoticons/smile.png)
Though it is hard to see how the error could be in the direction described.
If you move back to 0 does it move 0.48" the other way? (exactly?)
Replied by andypugh on topic need help configuring LinuxCNC
That is correct. But it is anyones guess whether the TB6560 manual you have matches the TB6560 board you haveWell, I have the controller set to 1/8 microstepping (I don't know why... ) but I did tell StepConf that Drive Microstepping was 8.0. Is that not correct?
![:-) :-)](/media/kunena/emoticons/smile.png)
Though it is hard to see how the error could be in the direction described.
If you move back to 0 does it move 0.48" the other way? (exactly?)
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16 Feb 2013 02:58 #30141
by rebeltaz
Replied by rebeltaz on topic need help configuring LinuxCNC
It does come back to zero consistently - which is more than I can say for Mach3!
![:whistle: :whistle:](/media/kunena/emoticons/whistling.png)
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