Grounding kossel mini frame

dc42

I recommend that you also connect mains ground to the V- output of your PSU. Just watch out if you use a USB connection to the Duet, see the wiki page on USB ground loops.

leif

Thanks for quick reply @dc42 . I was aware of ground loops and have been connecting to the Duet with laptop powered by battery alone which was suggested a safe option. I also think the new doku is very very good, so thank you very much for this

I updated the drawing as suggested and will wire up the rest of printer again shortly. I have also updated my steppers to 0.9 17HM19-2004S as suggested earlier in your blogpost. Practically my kossel mini came together by reading your blog, so thank you so much again

veng1

Why not use a large value resistor, say 1M, between V- and mains ground?

That will still bleed off a static charge but not, hopefully, impact ground loops as much.

c310

why not to ground stepper motors body directly to main earth?
...without connecting main ground to V-

i grounded mine and it seems to work without issues....

fcwilt

Hi,

Just to be safe I would not connect the PS connections V- and G without checking with the manufacture first.

In many, if not most, cases I think it will be fine but there are PS designs (at least on paper) where this connection would not be a good idea.

Frederick

Phaedrux

@veng1 said in Grounding kossel mini frame:

Why not use a large value resistor, say 1M, between V- and mains ground?

That will still bleed off a static charge but not, hopefully, impact ground loops as much.

I've also seen it recommended to use a diode between DC V- and Mains ground but I can't seem to find it anymore. I'm not an electrical wizard so I don't know if that's good advice or not. But the reasoning given was similar to what you mention.

c310

@phaedrux said in Grounding kossel mini frame:

I've also seen it recommended to use a diode between DC V- and Mains ground

@dc42 can you help us on this issue?

article WiKi_USB_ground_loops says that
"Disconnect the power supply negative output from mains ground. For safety reasons, this is not recommended."

So, questions:

Connect or not to V- to main ground? what is the risk of not connecting it?
put diode or resistor? what kind of parameters ?
if it is diode - which side / polarity ?

thanks!

dc42

@c310 said in Grounding kossel mini frame:

Connect or not to V- to main ground? what is the risk of not connecting it?

https://www.youtube.com/watch?v=3jYZDLOV4Jc

c310

@dc42 thanks for video.

it is clear with grounding PSU, but in the video ground is NOT connected to V-

should i connect it or not? if yes - diode (which polarity than) or resistor... ???

thanks!

dc42

I connect it directly on my delta.