Arduino CNC Shield Power Routing

[Desertboy]

Hi,
New to the forum, came from the 3D Printing world having conquered it and have to say... the open source software, firmware and hardware for 3D Printing is WAY more advanced than for CNC machines.

Anyway, as such I'm used to my motherboard shield powering the Arduino it sits on. However when I send power to the CNC shield (this being the name as well as description) the Arduino doesn't come alive. I've buzzed out the PSU-shield with no issues, tried shield positive to Arduino jack plug positive, which gave me a reading but the negatives didn't.

So, to clarify (as there doesn't seem to be much user friendly information out there)... does the CNC shield power the Arduino or does the Arduino use its host computer's power through the USB to power it?

Thanks for any help :)

The Arduino should power up from USB socket (It's 5v) and then wire your 24v power supply directly to the cnc shield, if you don't have a 24v power supply get one. If you are using 4 motors (2 for the lower axis) use all 4 axis on the cnc shield and set one of the axis as a clone so you can get the maximum out of your nemas.

First question is have you tried the uno without the cnc shield on it?

Arduino can only handle 5v if you pump 12v or above into the Uno you will fry it! The CNC shield is designed to pass power from the onboard power socket to the stepper drivers bypassing the Arduino. The arduino is powered by the USB socket or optionally the 5v plug on the Arduino board which is more for standalone arduino operations.

grbl is actually very good

Check out this page
http://www.instructables.com/id/3020...CNC-Shield-V3/

I found it useful although a lot doesn't apply to me.