I recently moved from (sea level) the San Francisco bay area to the Sierra foothills (3000ft elevation). The air is much dryer here and I ran into static electricity issues that I did not have at sea level. My machine kept cutting off when cutting PVC and running my vaccum, dust collection.
First thing I did was plug everything into a separate electrical outlet. The laptop, the router and the vacuum all on separate grounded outlets. This did nothing to fix the problem. I then ran a ground wire from the body of the router to a grounded outlet, this did nothing. I then also grounded my Z axis, still nothing helped the situation. Very frustrating, I was burning thru lots of material, losing money.
Frustrated I did not think I was going to solve this issue. At the hardware store I found some heavy gauge copper wire. I purchased 5’ length and I wrapped my vacuum hose (see images) and grounded one end. I was sure this was a waste of my time. It freaking worked! So very happy and relieved. No more static issues shutting my machine down.
will that hose has the wire imbedded into it, did you just strip one side and run a lead to a ground somewhere? did you find it easier to use the machine end or the vacuum end? I really need to do something similar.
William, Thank you.
Steven, Yea, that is not fun. So I found the copper wire in one of those return bins at the hardware store, it was already bare wire. Then, I purchased a heavy duty three-prong plug that was prewired. I terminated the hot wire ends and just wired the ground to my heavy copper wire and plugged that into a grounded outlet. Hope that makes sense. I can snap a photo if you like.
It makes perfect sense that the hose was building up static charge. Plastics are poor conductors of electricity and tend to build up charges on the surface of the material. In this case, due to the triboelectric effect of the chips / dust rubbing the inside of the plastic hose as they are sucked through it. I’ve seen / felt it personally using a shop vac with blue foam board (extruded polystyrene), including bits of foam that end up stuck via static around the nozzle end of the hose.
Any static protection measure should include a 1 MΩ resistor in series just before the earth ground to limit discharge rate and potential current through a user’s body. You can use a terminal strip to make a mechanically robust implementation like this:
A good video about static electricity in a woodshop dust collection system using PVC pipe. He frequently mentions the danger of an explosion that could result from an arc of discharging static being highly unlikely in a hobbyist shop.
In a CNC environment we are concerned with discharging static disrupting signals between sensitive electronic equipment particularly in digital controllers that may not have the best grounding being built into their designs.
As he says if static electricity is a concern you must use conductive materials (metal pipe). In the CNC world this probably means conductive flexible hose.
Just an observation from an old retired computer tech, somewhat competent hobbyist woodworker and marginally competent CNC user.
While I’m not an electrician the information provided would lead me to believe me to think your outlets themselves aren’t necessarily grounded coming from the main electrical panel. You tried 3 separate outlets that were “grounded” to the best of your knowledge with no luck.
Aside from your quick fix I would suggest that you check the panel and ensure that it physically grounded to earth or have an electrician check it for you. If not they would drive a grounding rod in the earth and connect a wire from there wiring in the panel.
I learned that just because an outlet is connected to a (green) ground wire doesn’t mean that the panel itself is grounded. Not sure when you new house was built but it’s a good idea to have it checked out by a professional.
Just food for thought.
Point taken, and thanks for your observation. I pulled the switch plate cover off and I see there is a green wire but I did not trace it back to see if it is actually grounded. I’m just satisfied I was able to figure this out. Now to clean up the connection/system. I’ll probably order one of those grounded hoses.
I don’t disagree with your points, but note that the electronics in question are sitting in a metal enclosure which is entirely grounded. And I would guess C3D has large ground pours on the PCB.
I think C3D would alleviate a lot of issues by using shielded cables - although a lot run through the X axis which is a faraday cage, there are still exposed sections that “could” pick up EMI (not static). I removed by BitZero as it’s also an EMI antenna plugged into the PCB.
People should really key in on using an inline resistor like dbotos mentioned… Static is no joke and for all intents and purposes is it a miniature lightning bolt. This resistor can keep you from curling your hair and since the static jump usually follow’s Murphy’s Law, it can also save your equipment by limiting the current when you go to touch your laptop or tablet to jog the cutting head.
I used bare stranded wire. Attached it to the wire in the hose. Ran it to ground that I ran to a ground rod outside. The ground is also on a buss bar. I am just a little bit anal. Router, bit runner, all go to the buss bar.