Fixing Electromagnetic Interference and Grounding a CNC

I determined that electrical interference is causing communication issues with the stepper motor encoders on my CNC. In this video I show you how I fixed this problem.

[tech]

Good work. The only remark is that you wanna start with pockets, and finish with contouring.

[jeffbeck]

Thank you very much. I finally got to test my completed CNC machine today, and my spindle is throwing all kinds of EMF making the machine not work properly. I like the fixes that you did and will try the same. I think shielding and grounding the spindle's power cable along with the spindle itself was probably what fixed it. ...but I like the idea of grounding the machine too.

[Festivejelly]

This is what I needed! I thought I was going crazy!

[joshuacaylor]

Great video man, thank you. Helping me build my plasma table right the first time

[ХристоАврамов-фх]

Dear Becky Schwantes
My name is Hristo, I am from Plovdiv, Bulgaria. I have read your comment to this video clip and
I have decided to write you (I have no another way to make this).
I have tried to make my first hobby cnc machine, but my experience of electronics is very small.
I have a question about Grounding. I have to note before, that our building is old, and there are
only 2 conductors, and we have not separate conductor for Grounding unfortunately. This system
is TN-C and TN-C-S. In this case, we have to use “neutral” for this kind of Grounding.
The main elements of electronic are: Arduino Uno; 3 steppers-NEMA 24- 3, 1 N.m; 3 stepper-drivers-
SH-750- 5A, PSU-s - one 36V DC for steppers, and other - 12V DC for fans, (5V for Arduino from
computer‘s USB).
I will not use a VFD for motor-spindle. I have intention to use routing motor-spindle, and I will
connect it directly to 230 V- AC, and will be no connection to controller.
I will Grounding 2 PSU by “neutral” in “star” point (in TN-C-S system), but I am afraid to connect
in this “star” point stepper drivers (GND) and Arduino (GND). I think, that it will be too risky.
To install separate ground rod is not easy task.
What do you think about this situation ?
Best regards
PS: Excuse me for my too bad English language.

[fvheel]

I just replaced all my steppermotor- and endstop wires with shielded cables on my 6040 cnc.
I have a 24v powersupply witch has the only ground-connection on the cnc at the 220v side (mains).
Can i connect all the shielded cables of the steppermotors and endstops to the ground of the 220v connection?

[rmp]

An electrical engineer told me aluminium foil shielding on wiring does nothing for emf problems. Remember it is an electrical magnetic problem. Aluminium will not block or shield against a magnetic field. I have had to separate stepper motor wiring and controller wiring with steal sheet metal partitions and ground the frame to get rid of hesitation problems.

[dd_Dedsec]

Please reply me back. Since i am facing the same issue. Are you using Sheilded wires for limit switches too?

[OKVanAutoUpholsteryBellGardens]

i have a plasma home made cnc table i i go to cut out a part it moves around erratically and my x and y axis move completely off course and it messes up my dont have my table grounded but how exactly can i ground it? theres a steel bean next to my table which goes into the ground, i was thinking of grounding into that but do i also have to utilize my ground pin built into my torodial power supply inside my electronics control box? will that help?

[cmoo]

What kind of shielded cable did you use. Are they flexible?

[OKVanAutoUpholsteryBellGardens]

i have a torodial power supply for my plasma you think if i connect my steel frame to the ground terminal on my power supply it will help with the noise ? im having issues with noise and my motors are moving very erratically.

[beykana]

Hi, can I prevent interference if I put a ferrite core on the cables?

[BossTweed]

How do you connect the ground from the cnc to the ground coming for the wall socket? Thanks in advance

[mertcapkin]

How did you connect the three wires to the house earth ground? Via the control box?

[kabadaluk]

No wonder why I get static shock when touching MPG hand wheel and frame gantry because not grounding properly. So I just need to connect / bonding the wire to the frame flow thru the control panel box earth is it.. thanks

[beckyschwantes]

Yikes, this is not a proper grounding application. You need a ground rod installed for the equipment ground. You don’t use your residential ground which has been bonded to nuetral. You always use a braided shield for any cable that will be flexing the foil shield will break. You absolutely never run high voltage in the same track as control voltage. If you insist on having them in proximity of each other you run them perpendicular never parallel. Also you are simply testing for continuity with your meter you are not comparing the potential. You did some nice work .... sink a ground rod and install it right. You don’t want to be fighting noise issues a couple years from now when that foil cracks and your shield is broken. Your grounding system should be capable of serving as a protection circuit and a location to disperse noise equally well! You seem pretty sharp. Look up Tpc cable they specialize in super flexing cables with any shielding option you might desire! Make a nice power cable and use that braided sleeve as a ground strap!