Homing not being saved

jsinicro · 9 May 2021, 00:52

Hi, I need to Home the machine every time after I turn power off. Is this the expected behavior?

fcwilt · 9 May 2021, 02:07

When you power on the machine you need to home all axes.

Frederick

deckingman · 9 May 2021, 05:49

@jsinicro The reason is that when you turn the machine off, you lose power to the motors, so there is no holding current. In that state, it would be easy to accidentally move the print head, but the firmware would have no way of knowing that had happened.

dc42 · 9 May 2021, 07:53

@deckingman said in Homing not being saved:

@jsinicro The reason is that when you turn the machine off, you lose power to the motors, so there is no holding current. In that state, it would be easy to accidentally move the print head, but the firmware would have no way of knowing that had happened.

More than that: when you power on and energise the motors, they will jump to a multiple of 4 full steps to match the phases of the motor current. So it's more or less guaranteed that they will move

jsinicro · 9 May 2021, 18:14

@dc42 OK, thankyou. I have a CNC machine as well and it doesn't force the homing sequence on every power on, that's why I was asking. I didn't realize but what you said makes sense, I think I should home the CNC machine every time as well.