Need Help Please... Mesa 7i76 conversion
- mjohnsonsa
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24 May 2016 17:40 #75048
by mjohnsonsa
Need Help Please... Mesa 7i76 conversion was created by mjohnsonsa
I upgraded my CNC router to use a MESA 7i76e instead of the Parallel port and now the steppers will not respond. I am not sure what to do next, I really need help, here is what I know from troubleshooting so far:
1. Router worked with Parallel port and C10 Controller
2. I know the MESA is working and communicating, I can trigger limit switches and it shows up in LinuxCNC that the limit switch has been triggered.
3. I know the steppers are getting power, I can feel them energized
Here is what I have tried:
1. I ran pncconf using all the defaults where possible (ini and hal attached)
2. I have tried hooking up the driver in two different ways, the first is the closest to how it was on my old C10 controller board like this:
TB2 PIN 2 -> STEP-
TB2 PIN 4 -> DIR-
TB2 PIN 6 (+5VP) -> STEP+ & DIR+
I also tried this (I am not sure if you are only supposed to connect two of the four but I tried all four as above):
TB2 PIN 2 -> STEP-
TB2 PIN 3 -> STEP+
TB2 PIN 4 -> DIR-
TB2 PIN 5 -> DIR+
My Drivers are these: www.cncconversionkit.com/home/187-4-axis...a-driver-dm556d.html and www.cncelectronicskit.com/. They show green lights, you can feel the steppers holding position, nothing obvious is different.
In my testing I modified the X and Y axis in the .ini to values that match my old parallel .ini config. I left the Z and A with the defaults out of the pncconf wizard.
Also, when I jog in linux CNC on the display it does show the movement as I jog, just the machine is not really doing the movement.
This is a new install of linuxcnc using the Wheezy ISO provided in the 2.7 download area. I then apt-installed the PREEMPT RT kernel (#1 SMP PREEMPT RT Debian 3.2.78-1) as well as linuxcnc-uspace through apt-get.
Not sure what other background information I can give to help you troubleshoot, .ini and .hal are attached. Thank you!
Matt
1. Router worked with Parallel port and C10 Controller
2. I know the MESA is working and communicating, I can trigger limit switches and it shows up in LinuxCNC that the limit switch has been triggered.
3. I know the steppers are getting power, I can feel them energized
Here is what I have tried:
1. I ran pncconf using all the defaults where possible (ini and hal attached)
2. I have tried hooking up the driver in two different ways, the first is the closest to how it was on my old C10 controller board like this:
TB2 PIN 2 -> STEP-
TB2 PIN 4 -> DIR-
TB2 PIN 6 (+5VP) -> STEP+ & DIR+
I also tried this (I am not sure if you are only supposed to connect two of the four but I tried all four as above):
TB2 PIN 2 -> STEP-
TB2 PIN 3 -> STEP+
TB2 PIN 4 -> DIR-
TB2 PIN 5 -> DIR+
My Drivers are these: www.cncconversionkit.com/home/187-4-axis...a-driver-dm556d.html and www.cncelectronicskit.com/. They show green lights, you can feel the steppers holding position, nothing obvious is different.
In my testing I modified the X and Y axis in the .ini to values that match my old parallel .ini config. I left the Z and A with the defaults out of the pncconf wizard.
Also, when I jog in linux CNC on the display it does show the movement as I jog, just the machine is not really doing the movement.
This is a new install of linuxcnc using the Wheezy ISO provided in the 2.7 download area. I then apt-installed the PREEMPT RT kernel (#1 SMP PREEMPT RT Debian 3.2.78-1) as well as linuxcnc-uspace through apt-get.
Not sure what other background information I can give to help you troubleshoot, .ini and .hal are attached. Thank you!
Matt
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- mjohnsonsa
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24 May 2016 17:41 #75049
by mjohnsonsa
Replied by mjohnsonsa on topic Need Help Please... Mesa 7i76 conversion
Also if it helps, here is my working config using the Parallel port and C10 control card
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24 May 2016 17:56 - 24 May 2016 18:00 #75050
by PCW
Replied by PCW on topic Need Help Please... Mesa 7i76 conversion
First:
DO NOT tie STEP/DIR pins to power pins!
This shorts out the output drivers and can damage them if multiple
outputs are shorted at once
Second:
You have the step length set to 1 ns, this is not going to work
I would set both steplength and stepspace to a minimum of 2000 ns
DO NOT tie STEP/DIR pins to power pins!
This shorts out the output drivers and can damage them if multiple
outputs are shorted at once
Second:
You have the step length set to 1 ns, this is not going to work
I would set both steplength and stepspace to a minimum of 2000 ns
Last edit: 24 May 2016 18:00 by PCW.
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24 May 2016 18:16 #75051
by mjohnsonsa
Replied by mjohnsonsa on topic Need Help Please... Mesa 7i76 conversion
Should I have all four STEP and DIR pins connected between the board and the driver? The reason I had 5V+ wired to STEP+ and DIR+ in that one test is because that is how it was wired when I was using the C10 board. The instructions telling me to do that are here: www.cncelectronicskit.com/
As for the 1ns, you will notice that was only one the X and Y as one of my test, I changed steplen and stepspace to 2000 and it still is not responding.
What else should I try? I think I first need to confirm what the wiring should be between TB2 and the driver, is it two wires? four wires? Also, am I not using the correct outputs in my config possibly? Perhaps my pins are based on using a daughter card (which I am not) I am using TB2 on the board.
Thank you.
As for the 1ns, you will notice that was only one the X and Y as one of my test, I changed steplen and stepspace to 2000 and it still is not responding.
What else should I try? I think I first need to confirm what the wiring should be between TB2 and the driver, is it two wires? four wires? Also, am I not using the correct outputs in my config possibly? Perhaps my pins are based on using a daughter card (which I am not) I am using TB2 on the board.
Thank you.
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24 May 2016 18:54 - 24 May 2016 18:54 #75052
by PCW
Replied by PCW on topic Need Help Please... Mesa 7i76 conversion
You can connect all 4 (differential mode) this has the advantage of higher noise immunity
you can also use single ended mode, for example:
tie drives +DIR and +STEP to +5V and drives -DIR to 7I76E -DIR
and drives -STEP to 7I76E -STEP
Do you have the drives timing specifications?
in absence of actual timing specifications I would just set the step width wider
until it starts working and then add about 100% more
you can also use single ended mode, for example:
tie drives +DIR and +STEP to +5V and drives -DIR to 7I76E -DIR
and drives -STEP to 7I76E -STEP
Do you have the drives timing specifications?
in absence of actual timing specifications I would just set the step width wider
until it starts working and then add about 100% more
Last edit: 24 May 2016 18:54 by PCW.
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24 May 2016 19:15 #75053
by mjohnsonsa
Replied by mjohnsonsa on topic Need Help Please... Mesa 7i76 conversion
Okay, I have all four wires set up on all drivers now.
I do not have timing information on the drivers, on the drivers you can set the amperage and the 'Pulse/rev'. You can see it here: www.cncelectronicskit.com/wp-content/upl...it-current-table.png
I can try setting the step width wider, which setting is that though? the STEPSPACE? or STEPLEN?
I do not have timing information on the drivers, on the drivers you can set the amperage and the 'Pulse/rev'. You can see it here: www.cncelectronicskit.com/wp-content/upl...it-current-table.png
I can try setting the step width wider, which setting is that though? the STEPSPACE? or STEPLEN?
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24 May 2016 20:43 #75054
by mjohnsonsa
Replied by mjohnsonsa on topic Need Help Please... Mesa 7i76 conversion
Do the PID settings in the .ini and the .hal only have to do with servo configurations? is all that necessary for steppers?
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24 May 2016 21:17 - 24 May 2016 21:19 #75055
by PCW
Replied by PCW on topic Need Help Please... Mesa 7i76 conversion
I would try 5000 for steplen and stepspace
Yes the PID stuff needs to be there (though P should be set to 1000 for a 1 KHz servo thread rate)
This is because the built in position mode in the step generation part of the HM2 driver
doesn't tolerate jitter very well and the PID implementation is much more resistant to large
jitter spikes
hmm 5000/5000 might be too slow for you velocities
If you google the DM556 drives, they specify 2.5 usec (2500 ns) minimum pulse width
so 3500 (= 3.5 usec) should be good, with some margin above the minimum
Yes the PID stuff needs to be there (though P should be set to 1000 for a 1 KHz servo thread rate)
This is because the built in position mode in the step generation part of the HM2 driver
doesn't tolerate jitter very well and the PID implementation is much more resistant to large
jitter spikes
hmm 5000/5000 might be too slow for you velocities
If you google the DM556 drives, they specify 2.5 usec (2500 ns) minimum pulse width
so 3500 (= 3.5 usec) should be good, with some margin above the minimum
Last edit: 24 May 2016 21:19 by PCW.
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24 May 2016 21:35 - 24 May 2016 22:17 #75056
by mjohnsonsa
Replied by mjohnsonsa on topic Need Help Please... Mesa 7i76 conversion
Okay, I added the PIDs back in the files and I also set the STEPLEN and STEPSPACE to 3500 and I have movement! (although very slow).
I would not be asking this question if I could find it in the docs but what should the values be for all these for my configuration? The man pages say what the values are but that is not very helpful if you have no clue how to determine what values they should be for my setup. I am using a 5.08 TPI pitch ball screw, the CCK5560 drivers I linked in an earlier post, and NEMA 34 steppers, I would really appreciate if you or someone could just tell me what the below settings should be for my setup (I entered my current values for reference). I have already wasted 2 days fiddling with this unsuccessfully:
MAX_VELOCITY = 1.8
MAX_ACCELERATION = 6.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 1.25
STEPGEN_MAXACCEL = 8.50
P = 50.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
# these are in nanoseconds
DIRSETUP = 200
DIRHOLD = 200
STEPLEN = 3500
STEPSPACE = 3500
STEP_SCALE = 8625.6
I would not be asking this question if I could find it in the docs but what should the values be for all these for my configuration? The man pages say what the values are but that is not very helpful if you have no clue how to determine what values they should be for my setup. I am using a 5.08 TPI pitch ball screw, the CCK5560 drivers I linked in an earlier post, and NEMA 34 steppers, I would really appreciate if you or someone could just tell me what the below settings should be for my setup (I entered my current values for reference). I have already wasted 2 days fiddling with this unsuccessfully:
MAX_VELOCITY = 1.8
MAX_ACCELERATION = 6.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 1.25
STEPGEN_MAXACCEL = 8.50
P = 50.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
# these are in nanoseconds
DIRSETUP = 200
DIRHOLD = 200
STEPLEN = 3500
STEPSPACE = 3500
STEP_SCALE = 8625.6
Last edit: 24 May 2016 22:17 by mjohnsonsa.
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25 May 2016 00:09 - 25 May 2016 01:09 #75058
by PCW
Replied by PCW on topic Need Help Please... Mesa 7i76 conversion
This is not something you fiddle with
This is something you research and setup based on the requirements of your hardware
The step timing is specified the in the DM556 manual (as are the direction setup and hold times which should be 5000 ns each)
The step scaling is determined by the drives microstep/full step settings (also in the DM556 manual) so you would need to specify how you have these set before it can be checked.
You have the stepgen maxvel set to less than the max velocity which will cause a following error when you get to that speed
as the comments say, the stepgen maxvel should be set to 1.25X the max velocity for that axis
This is something you research and setup based on the requirements of your hardware
The step timing is specified the in the DM556 manual (as are the direction setup and hold times which should be 5000 ns each)
The step scaling is determined by the drives microstep/full step settings (also in the DM556 manual) so you would need to specify how you have these set before it can be checked.
You have the stepgen maxvel set to less than the max velocity which will cause a following error when you get to that speed
as the comments say, the stepgen maxvel should be set to 1.25X the max velocity for that axis
Last edit: 25 May 2016 01:09 by PCW.
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