So I have read the past posts I could find regarding the use of jog knobs on a CNC and the possibility of cooking drivers. That being said, I then see the jog knob installation video from the parts page showing them being installed on an OB Mini Mill. So I guess my questions is.... can I use them or not? Current setup is a custom build using; C-Beam linear actuators OB NEMA23 steppers BBx32 Thanks in advance for any input!
not much better to install home limit switches, home the machine, then jog electronically to anywhere you need to go. There really is no need for knobs at all. why? because when you turn a stepper motor it acts as a generator, a rather good one, and very quickly exceeds the power supply voltage, killing the drivers and sometimes the power supply with power coming in 'backwards' . Some drivers are resistant, most are not. No power supply I know can stand having excess voltage on its input.
I have and use home limit switches, sometimes I need to move various axis small amounts for various reasons when it’s over the workpiece. As I mentioned before n my original post, I understand the reasoning mentioned for not using them but there also had to be some reasoning behind including them with the OB MiniMill, right? Can someone explain that?
That movement is given to you by the jog buttons, or by direct commands in the serial console, or by macros that you create to do what you need. It is bad for the drivers when you turn the motors by hand, even with power off you can kill the drivers or psu. I cannot answer that, maybe @Mark Carew can remember? Whatever the reasons back then, they are supplanted now by better knowledge and better software that provides for manual movement via real jog commands.
Maybe I’m missing something on the jog commands via OB control, I find it tedious at times to swap back and forth between .1, 1, 10, 100 mm movements (232.3mm for example). Is there a way to redefine the default move increments or even move a specific distance, other than using the command line?
are these specific distances ones you use often? then define a macro for it. or perhaps you need a probe and macros to drive it so you don't have to move specific distances, the machine can find it's own position.
Didn’t even think about using continuous jog for that….♂️ and I have the OB xyz probe so I’ll give that a shot. Thanks again for the help guys and Happy New Years!!
