DIY CNC Milling Machine From Scratch

**Clive S** · 20-09-2016

Originally Posted by nairepooc

All this talk of Grounding and Earthing, is making me even more confussed!
Is Grounding connecting to 0V dc and Earthing to a Star earthing point or am I missing something, or are we mixing up the terms?

Grounding and Earthing often creates a lot of confusion and to some extent depends how old you are. But you don't connect your DC ground to the Star point which is the point where all the screens connect to and then that is connected to the AC earth. The reason for the Star point is to get rid of earth loops (or ground loops if you are old).

Sometimes you have more than one DC power source and again somtimes you have to connect the various DC power -ve together. Hope this helps a bit.

**Boyan Silyavski** · 20-09-2016

Sorry, my mistake then. In my mother language -ground and earth is the same word, not 2 different. So when i say Ground or Earth, i mean the same. Stick 2m long in the ground that is connected to all grounds in house line electricity, mind not the 0 or phase. If we are talking for DC i say Negative or Common ground. I am not sure that's right, but as English is not my native language ...

**Davek0974** · 20-09-2016

Dictionary wise both are same.

But in electrical engineering context both words differ in scope. Ground is a general term that refers to a reference potential against which all voltages are measured. Earth is same as ground but used in context of power systems because the ground here is implemented by burying copper conductors deep down into Earth.

Since Earth has minerals, moisture and it has practically infinite volume, the current flow is only limited by contact resistance between ground/earth conductor and soil. Because of this, on the distribution side, the neutral is connected to earth. On receiving side, fault current from one of the phases can flow into the local earth conductor and make its way to the neutral at distribution side. Apart from being a sink for fault current, the Earth conductor also serves as a return path for instrumentation systems.

:)

**njhussey** · 20-09-2016

Originally Posted by Davek0974

Dictionary wise both are same.

But in electrical engineering context both words differ in scope. Ground is a general term that refers to a reference potential against which all voltages are measured. Earth is same as ground but used in context of power systems because the ground here is implemented by burying copper conductors deep down into Earth.

Since Earth has minerals, moisture and it has practically infinite volume, the current flow is only limited by contact resistance between ground/earth conductor and soil. Because of this, on the distribution side, the neutral is connected to earth. On receiving side, fault current from one of the phases can flow into the local earth conductor and make its way to the neutral at distribution side. Apart from being a sink for fault current, the Earth conductor also serves as a return path for instrumentation systems.

:)

Look who swallowed a dictionary.....nice clarification, cheers Dave 😊

**Clive S** · 20-09-2016

Yes Dave good clarification one of the problems that has been highlighted is that different disciplines treat the words different such as in electronics PC boards often have a ground plane that is not connected to earth but to DC ground or signal ground in this case ground is not earth.

**Davek0974** · 20-09-2016

Yep, it's a thorny subject, don't forget the chassis ground, signal ground, RF ground - there are loads of grounds but they do not have to be connected to earth :)

**totts** · 20-09-2016

My head hurts! Haha think I'm going to come back to it when I have more than half an hour to play!

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**picatinny** · 22-09-2016

Keep on the good work mate

**picatinny** · 22-09-2016

Can you post more pictures

**totts** · 18-04-2017

Hello all, i had found that disconnecting the shield connection to the vfd to motor wires cured the problem, hence why i haven't been on here as i have been playing with the machine :) now i have a bit of free time where the machine can make some bits for itself!
I might actually finish it as intended! Hanvent come across any other problems apart from that!

I have been looking at getting a trough made up for it, so i can get some coolant running, as this seems to be the limiting factor of pushing its machining capabilities.

Also im not wanting to stand around for 2 hours with a bottle of coolant :)