Please help! emi cutting acrylic (solved, bad outlet)

After years of cutting acrylic I am suddenly now having problems with emi. I have already confirmed it is only when cutting acrylic.

So far I have done everything listed already in the FAQ for emi with the exception of replacing my brushes(they are on order)

: separate outlets, run without dust collection, removed battery ups, separate router cable from controller cables, install ferrite cores on every cable, not located next to breaker box, etc. Etc…

I have also attached ground wires to both x and y axis rails, control box, z slider, router, and having everything tied together on a terminal strip that is also grounded to the earth ground on my outlet. (See pictures) I have also sanded to bare metal where connections are placed.

I’m at my wits end and don’t know what else to do. What’s frustrating is I haven’t had this problem for years but now do. Any help would be appreciated.

First thing to check is if it fails with the vac on or vac off. If it works with vac off, you know to focus on the vac.

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I thought I mentioned above but yes this is still happening with all dust collection off

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This is a stretch but by any chance are you using a different brand of acrylic?
Not with EMI per say, but I have noticed over the years different plastics have more or less static cling when cutting them on the table saw. So maybe its the formulation?

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I thought about this too. I have changed brands but it was long enough ago to rule out as being the problem

I just checked all of my outlets and looks like one of my outlets is not Making continuity with ground. I’m thinking it’s a really good chance this is the issue will report back after I replace.

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The outlet sounds like a likely culprit. If that doesn’t work, maybe try grounding your workpiece. I know it sounds strange, but in a different context I actually had a static electricity buildup on a plastic piece disrupt my electronics. Grounding the plastic solved the problem.

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SOLVED! I had two of these outlets that were no longer internally grounding. The wiring was fine but within the outlet the ground was no longer making continuity. EVEN THOUGH MY OUTLET TESTER DID NOT INDICATE OPEN GROUND this was still the case. This explains why the sudden change after several years without a problem with emi. Hopefully this is will help someone in the future.

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