I had a nasty problem with static when I first got my CNC machine... Lots of ruined work... It took me a while to figure out what the issue was, so that added to the frustration. Finally I thought I should Earth Ground it, and that did the trick. I drilled a hole through my concrete floor, drove a 6' long copper ground rod in, and grounded the router chassis, control box, and spindle. Before I dove the 6' copper rod in, I took a look at the plans for the building to see if there might be anything under the the slab where I drove the rod.
I disconnected my dust collector from the CNC at the same time, too. Even though I had a grounded copper strap run through it, the humidity is so low here that I was getting visible static discharges. So yeah, it makes a mess, but I don't have any static problems anymore.
Hope this helps,
Aspire 9.5 - FlexiEXPERT 11 - Vytek Rebel 4' x 8' - 5HP Perske Spindle