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General Mach Discussion / Initial Loading of g21 and Z axis absolute versus machine cordinates
« on: February 01, 2008, 01:48:21 AM »
Hi,
I have just switched to Mach 3 from EMC . I have gone through the Mach 3 manuals but I am not finding what I need. Really hoping some of you experts can help me:
1) I want Mach 3 to load G21 (mm) instead of G20 (Inches) in its intiial startup - I would like to avoid changing the configuration to mm because then I believe I will have to adjust the Motor tuning - (my leadscrews are 20rev per inch and calculating the number of steps per mm will be messy) but if this is the only way I guess I will have to do it.......
2) My system is closed loop- My Machine coordinates should always stay the same. So when I shut down and then boot up they come up the same as. If I home an axis, the corresponding absolute position readout will adjust to reflect its new zero point. at any time as the axis moves I can toggle the readouts between the shown absolute position and the machine coordinates which are always zeroed to an unchanging point-
However, I am noticing that my Z axis is now not working the way I expect. When I shut down, lets say my z axis reads 10 on absolute and -5 on machine, however,when I boot up the Machine coordinate and absolute coordinate will both display 10. The x and y behave as they should. How do I fix the z axis machine coordinates readout?
(I think I must have messed this up trying to adjust something else)
3) Following from Question 2, I want to set my soft limits base on my machine coordinates is this thinking correct?
if so, how do I select my home position and then zero my machine coordinates?
And then from this home position I can then set my soft limits ie x-100 to +100 etc I am correct?
This is important because I was informed that I do not need to home my machine with limit switches with this system (which I did before) because it always knows the position of the axis. However I want to make sure I am working within a clearly defined envelope.
I really appreciate your help,
Many Thanks,
Steve
I have just switched to Mach 3 from EMC . I have gone through the Mach 3 manuals but I am not finding what I need. Really hoping some of you experts can help me:
1) I want Mach 3 to load G21 (mm) instead of G20 (Inches) in its intiial startup - I would like to avoid changing the configuration to mm because then I believe I will have to adjust the Motor tuning - (my leadscrews are 20rev per inch and calculating the number of steps per mm will be messy) but if this is the only way I guess I will have to do it.......
2) My system is closed loop- My Machine coordinates should always stay the same. So when I shut down and then boot up they come up the same as. If I home an axis, the corresponding absolute position readout will adjust to reflect its new zero point. at any time as the axis moves I can toggle the readouts between the shown absolute position and the machine coordinates which are always zeroed to an unchanging point-
However, I am noticing that my Z axis is now not working the way I expect. When I shut down, lets say my z axis reads 10 on absolute and -5 on machine, however,when I boot up the Machine coordinate and absolute coordinate will both display 10. The x and y behave as they should. How do I fix the z axis machine coordinates readout?
(I think I must have messed this up trying to adjust something else)
3) Following from Question 2, I want to set my soft limits base on my machine coordinates is this thinking correct?
if so, how do I select my home position and then zero my machine coordinates?
And then from this home position I can then set my soft limits ie x-100 to +100 etc I am correct?
This is important because I was informed that I do not need to home my machine with limit switches with this system (which I did before) because it always knows the position of the axis. However I want to make sure I am working within a clearly defined envelope.
I really appreciate your help,
Many Thanks,
Steve