AC Servo change to run

 Hi..have an ac servo motor setup as 4th axis on wood lathe for position to carve....now i was hoping to use same motor for continuous run as lathe turning...Is this doable?...if so does it require any additional wiring/...I have a Mesa 7i96s  with ethernet..I normally would just try and figure out but I am very pressed for time on this one so any help would be greatly appreciated..

Thanks!,

Rick

I'm not sure that you can do that within a single Linuxcnc configuration, but you can set up 2 separate configs, one using the servo as a 4th axis and a separate one where it is configured as a lathe spindle. Both configs could reside in the same config directory and share most of the config hal files. They would need to have their own ini file though.

Thanks for reply..so I just need to lookup how to configure as spindle...no wiring...speed controlled by gcode?...motor driver would need parameters changed or can that be done through linuxcnc?

Thanks again!!

I don't think you would need to change anything in your servo drive. The only changes should be how it is seen and commanded inside Linuxcnc.

How is your servo currently commanded? I presume it is by step/dir commands in position mode? That would not have to change, you would simply have to change what signals are commanding the Mesa hardware stepgen so that they are commanded by the spindle commands instead of the joint that it is currently commanded by.

OK...so would I still need a new INI file?...I have been trying to make a new configuration by copying original which has 9 axis, but it is not working..was just copying and renaming...missing something....but if that is not necessary even better!!

Thanks again,

Rick

You can configure it as C axis using the caxis or orient component, and work in both functions, i.e. in velocity or position mode.

You should be able to take the oritinal working ini file and copy it into it's original configuration directory, Saving it with a new name .ini.

Then you without making any changes to the original ini file other than it's name start the configuration. It of course will still be the same but have a new name. Then start making small changes to the ini file. You need to be aware of any variable references to the ini file that the hal file(s) use, and if any of them refer to sections of the ini that you are changing you will need to address them. These are very common in the sections of hal code referring to the joints and axis. There is a good chance you will have to make a copy of the main hal file, rename, and make changes there to go along with your ini changes.

I have a something similar setup and you should be able to do it with the one configuration. Since linuxcnc supports multiple spindles I just made another spindle instance and then used a mux2 component to switch between outputting the axis velocity and spindle velocity to the mesa stepgen.  I think I just used the spindle.1.on signal to switch the mux2 component.  That way when I issue m3 s100 $1 it will run the second spindle at 100 rpm.  There could be some issues keeping position if you switch back and forth between the modes depending on how things are setup.    

Thanks to each for reply's...Going to get back to that in a day or so so will likely struggle a bit...but that is the way it works!