Im new, am a 3D designer. Need a New cnc machine and need advice and guidance

[Neale]

A stepper motor has two sets of coils, say A and B. If you home the twin-motor setup, it might be that the home positions correspond to A on one and B on the other energised. Switch off, switch on again, and some drivers (I suspect all analogue drivers) will energise A rather then remembering the last coil used, so the gantry will be slightly off-square. I'm assuming that a rehome operation will reset this, but the moral is that you can't rely on the system remembering exactly where it was when it was switched off. Slightly more complicated if you are using micro-stepping but the principle is the same. Small effect if you do it once, but the error could accumulate over a number of on/off cycles unless you rehome at the start of each session.

[Clive S]

A stepper motor has two sets of coils, say A and B. If you home the twin-motor setup, it might be that the home positions correspond to A on one and B on the other energised. Switch off, switch on again, and some drivers (I suspect all analogue drivers) will energise A rather then remembering the last coil used, so the gantry will be slightly off-square. I'm assuming that a rehome operation will reset this, but the moral is that you can't rely on the system remembering exactly where it was when it was switched off. Slightly more complicated if you are using micro-stepping but the principle is the same. Small effect if you do it once, but the error could accumulate over a number of on/off cycles unless you rehome at the start of each session.

Thanks for that Neal I would assume that most people would home each time they fired the system up and if they did not have home switches they would zero on the part. So generally would not be an issue. ..Clive