Grounding the machine.

[Tom Bachman]

I have read, off and on, about static electricity causing issues and to make sure that the machine is properly grounded.

Here's my question, I bought a roll of 12 gauge stranded wire, so how do I ground the machine, to eliminate this static?

Is each motor grounded? The frame? I'm at a loss and need some input.

I'm still awaiting the return of the control box from the repair facility. The modules that it needed are only made in China and they must have been sent on the slowest boat from there. :D

[mclimie]

Things I would do -

If you have dust collection, start there and ground the hose to the collector.

Then I would do a continuity test from the bit back, one thing at a time, until that test is broken. Bit to carriage, bit to gantry (be sure to pierce aluminum oxidation/anodizing - or go to bolts), then bit to X rails/extrusion. If you get a signal all the way there, it simplifies grounding as you don't have to ground every single hop.

I haven't had problems with the Bot yet, but I did have problems with static buildup on a smaller machine cutting HDU in the winter. I even went as far as clamping aluminum foil under the HDU and running a test/patch cord to earth in addition to the frame. It helped a lot.

The biggest problem seems to be when the easiest path is through the USB port. Even with a laptop using a transformer that you'd think is isolated, USB is earthed, so if that is the path of least resistance, problem! Here's a helpful video on that (he covers the USB trap in this somewhere - lots of great info on mains/earth):

https://www.youtube.com/watch?v=xaELqAo4kkQ

Marc

[tri4sale]

I had comm issues until I grounded my machine. Here is what I did:

1. Wire connects to router
2. Wire runs into small hole in dust collector hose (sealed after running wire)
3. Wire follows dust collector hose back to dust collector (small hole again exiting the hose and then sealed).
4. Wire grounded to bare metal spot on dust collector (I scraped off some paint at a bolt and attached wire to bolt/bare metal)

Since doing that I have had no comm issues.

[Gary Campbell]

These may help

[cowboy1296]

I just went though this. Its very dry here in my part of Colorado and static may have given me some grief. My hose has a ground wire in it running to my dust collector but the two were not grounded together. After connecting a ground wire from my dust collector back to the frame of the buddy, i have cut close to 60 hours without an issue. I do primarily 3-d.

[mclimie]

Out of curiosity, I did continuity on our PRS A here at work today, and I get a signal all the way from the collet to the bolts on the frame, even the metal cabinet. I get 5-8 ohm between the collet and a frame bolt. It should allow us to handle static from one point on the machine if it turns out to be a problem for us.

I have to believe the cabinet is grounded for safety - there is a green wire on the earth busbar that (doesn't match the others - motor wires, etc) being routed around the underside of the panel where I can't see it terminate.

Marc

[knight_toolworks]

it is best to get hose with wire in it then you just strip each end and connect them.

[genek]

These may helpcan static cause system to say missing com Was running good all day then all of a student at the beginning of a file it said missing com. Re started system and the next time it was in the middle of the cut again missing com.

[dlcw]

can static cause system to say missing com Was running good all day then all of a student at the beginning of a file it said missing com. Re started system and the next time it was in the middle of the cut again missing com.

Improper grounding can cause all kinds of problems on a CNC operation. Properly grounding everything together and to a common ground point eliminates static and ground loops. Every part that moves or is bolted to another part should be tied together with at least #14 or #16 grounding wire. I tie all my table legs to the frame rails, all diagonal supports to the legs, spindle to the Z-car, Z-car to the gantry, gantry to the frame rails, etc. Paint can act as in insulator so relying on bolting two parts together and having them electrically connected is not going to happen. That's why you have to connect them with a wire to bare metal on each part. Yes, you will have to scratch some of the pretty blue paint off. You can run specialized grounding wire thru the DC hose to take away static charges built up inside the hose. I served 23 years as an Electronics Technician in the Coast Guard designing and implementing grounding systems for LF, MF, HF, VHF, UHF and microwave communications systems as well as shielding computer and digital telephone systems from very high powered HF transmitters and 1.5 million watt LORAN transmitters.