EMC2 config Questions
Coming from Mach3 environment I find it daunting to configure Linuxcnc-2.7-wheezy.
My cnc is a gantry 3 axis (X,Y,Z) machine with 2 steppers on the gantry (Y & A), approx. cutting area 36”x28” and I will use a G540 and a Chinese 1.5kw VFD with a water cooled 1.5Kw Spindle.
I have copied the Linuxcnc manual, almost 248 pages from here
About LinuxCNC
but despite reading, the actual practice it’s not easy
For now I have difficulty understanding how to configure the printer port pins on the EMC2 Stepconf Wizard. I notice on the pop-up windows there are descriptions for the axes plus and minus limits and I find it strange because there aren’t enough pins on the printer port to assigning pins to so many items. So how do I configure my cnc?
I'm attaching page 7of10 from the G540 manual indicating the DB25 pinout which I try to follow
Perhaps someone can give me a hint on how to get going?
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Nicolas
Re: EMC2 config Questions
Pins 18-25 are always ground, so you can't change them and LinuxCNC Stepconf wizard doesn't list them.
The pins listed as input or output in the GECKO manual are for whatever inputs or outputs you want.
VFD PWM is only if you are hooking up a VFD. Ignore this one at least to start
The fault pin from the gecko you don't need to use
That only leaves pins 2-9 and 16 that you have to set.
Re: EMC2 config Questions
ok, I will give a try to set these pins and see the resultsOriginally Posted by 109jb
BTW my PC for now is not connected to the cnc. I dont know if that makes any difference
Thanks for the help
Nicolas
Re: EMC2 config Questions
Looks like it’s more difficult to configure Linux than I thought because I still get the “RTAPI Error, Unexpected real-time delay on task1. Run Latency test and resolve before continuing”
My questions now are:
Since I will use G540 and stepper motors for the output pinout preset I select Xylotex. Is this a good choice or I should choose TB6540 4 axes?
The driver timing settings are
Step time 1000
Step space 2000
Direction hold 200
Direction setup 200
Are these values good for the G540 with stepper motors and single start ball screws with 10mm lead?
Nicolas
Re: EMC2 config Questions
Those numbers are step/dir drive timing and not related to the scaling (the scaling is set on
stepconfs axis pages)
A real time error means your PC cannot meet the base thread timing you have selected with stepconf
(any PC/parallel port system like mach 3 will have the same kind of issues)
Have you run a latency test? (the latency test can be launched from stepconf)
Did you enter the maximum jitter value determined from the latency test in the Base Period Maximum Jitter field?
( You should let the latency test run for at least 5 minutes and stress the PC (run videos etc))
Re: EMC2 config Questions
As PCW_MESA noted, the “RTAPI Error, Unexpected real-time delay on task1. Run Latency test and resolve before continuing” error you are getting has to do with the speed of your computer. You must run the latency test to determine the maximum jitter.
http://linuxcnc.org/docs/2.7/html/in...ency-test.html
You really need to read the documentation that I linked in your previous thread
LinuxCNC
You can start with this:
Stepper Configuration Wizard
Re: EMC2 config Questions
Use driver type Gecko540 on the first page which will automatically set the proper timings.
On the paraport pinout page, set the pinouts to match the G540 manual. If it is a feature you aren't using then set it to "Unused". Don't use any preset unless it is G540
Re: EMC2 config Questions
I did not know the scaling is set on the axes pages neither I notice that these number can be changed. On X, Y, and Z axes I have
Time to accelerate to max speed 0.1000s
Distance to accelerate to max speed 0.1000in
Pulse rate at max speed 3200Hz
Axis scale 200x16x(1.0/1.0)x0.500=1600 Steps/in
But on the A axis I have
Time to accelerate to max speed 0.1000s
Distance to accelerate to max speed 0.1000deg
Pulse rate at max speed 12800Hz
Axis scale 200x16x(1.0/1.0)x2000=6400 Steps/deg
I know the A axis values are wrong but never thought that the values at the bottom of this page were configurable. Should I change to match the Y axis?
So what is an acceptable scaling number and how do you figure this out?
I did run the latency test and the number in the stepconfig “Base Period max Jitter” is 15000ns.
I run the Linuxcnc on my VMware virtual PC, does this make any difference?
As I mentioned I did copy the Linuxcnc manual and reading now to see what’s involved but not I will print now the pages just for the Stepper Configuration Wizard and hopefully afterwards I will be like a “pro”
Thank you both for your time
Nicolas
Re: EMC2 config Questions
A axis scaling is in degrees and linear axis (X,Y,Z) scaling is in machine units so they will not be the same
Linear axis velocities will be in inches or mm per second depending on what units you select on the base page,
A axis velocities are in degrees per second
Scaling is set by filling the axis page settings properly (for example a G540 uses a Driver Microstepping setting of 10 and Motor steps per revolution of 200)
The other scaling settings depend on your leadscrew pitch, units (inch or mm), and any gearing between the motor and the leadscrew
You must set Base Period max Jitter manually after running the latency test
(the 15000 number is just what stepconf starts with)
A real time OS will not work under VMware
(it will run but cannot control a machine because you will have huge latencies)
Re: EMC2 config Questions
My A axis is slaved to Y and they should be the same. How can I achieve this?
Perhaps there is another way with Linux?
Nicolas
Re: EMC2 config Questions
Once again, You really need to read some stuff. Based on the questions you are asking, you have not read the documentation that is available.
As for a slave axis, you simply change those pins to match the axis you want to follow. For example, pin 8 of the G540 is A-axis step, and pin 9 is A xis direction. In the parallel port configuration for LinuxCNC you just set pin 8 as y-axis step and pin 9 as Y axis direction. Now the a-axis of the gecko will follow the Y-axis command movements.
Re: EMC2 config Questions
Pages 18 to 30 of the Linux guide are for the Stepper Configuration Wizard and reading did not help very much. However as a newbie I probably must read it again and again. I remember when I got into Mach3, it took me a few months just to get the feel of it including the help from their forum. I find Linux very difficult including the file structure and terminal commands which are not similar to Windows.
In other words it will take some time before I can just say I’m comfortable with Linux. It’s a great OS but very different
I appreciate your help
Nicolas
Re: EMC2 config Questions
I have installed Linuxcnc on a desktop PC and now I don’t get the error message. As it was mentioned it was the VMware environment. It doesn’t mean that out of the woods yet but at least it’s a step forward
How can I remove the login / password which pops up every time I reboot? I understand the security issues
Is there a command to find the installed version?
Nicolas
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