EMI | Screen Flickering, Blank, or Black Screen, Randomly Loosing Zeros, Freezing, Disconnecting or Random Happenings

EMI, Flickering, Black or Blank screen, Random Axis movements:

If you have verified you have the cables connected correctly (screen MUST be connected to wall power) and the screen is blinking on and off during a cut, you may be experiencing EMI.

  • Ensure you have the controller and screen on one outlet, and the vacuum and spindle/router on a separate circuit/outlet. Usually this is enough to stop EMI. However, some extreme cases we’ve seen is: the separate circuits wired but both in the same box (defeating the purpose), router cords draped on top of rails touching the metal parts (directly sending the EMI through the machine), machines placed directly Infront of breaker boxes (directly where all EMI will flow to), metal electrical conduit running along the wall where the machine is next to, sending EMI through the machine when gantry’s are jogged next to the conduit. Another was the machine randomly moved as soon as the air conditioning/furnace turned on.
    These are just a few cases but hopefully they will raise awareness of things to look out for.

  • Remove any power strip, surge protector or battery backup and plug directly to the wall outlet. If that does not correct the issue, consider placing ferrite cores on each cable that connects to the screen: https://amzn.to/2XDpH0O

  • CNC machines and vfds/spindles should not be used on a gfci outlet.

  • Another item that can add to EMI is wear on the Makita router brushes. The more worn the brushes are, the harder the router must work and also adds more arcing and therefore more EMI or disconnects. When in doubt, change the brushes: Amazon.com: Carbon Motor Brushes Compatible with Makita RT0700C RT0700CX3 RT0701C Compact Routers 3703 1/4" Laminate Trimmer 6830 Screwdriver 9523NBH Angle Grinder 5 Pairs : Tools & Home Improvement

Vacuums / Dust collectors:

create a tremendous amount of static electricity, a large source of EMI. Grounding your vacuum (usually with coper wire) can help alleviate this potential source.

  • To Test, remove the vacuum from the machine and run without it. If it is successful, the vacuum is adding emi/static and need to be grounded.
  • ensure no part of the vacuum hose is touching or resting on the machine or the machines rails.

* Also, never have your spindle/router cable run in parallel with the unsheilded motor wires.

What is emi? Electromagnetic interference - Wikipedia

Symptoms of not connecting correctly, touch doesn’t work and screen flickers black.



*We do not recommend having any part of the CNC plugged into a GFCI outlet or breaker.