Vacuum grounding

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Barry Anderson
Posts: 52
Joined: Sun Dec 21, 2014 9:55 pm

Vacuum grounding

Post by Barry Anderson »

I use a shop vac most of the time, and a vacuum boot some time. As I vacuum the spoil board between projects, I feel the static electricity. I think it is causing me problems with computers, and controllers. I have 2 machines, and 3 controllers. I have had the board replaced in all 3 control boxes, 1 twice. Next Wave advised me to ground the box which I have. I am interested in grounding the vacuum and the vacuum boot. Any suggestions on the easiest way to accomplish this?

thanks for any help.

Barry Anderson
Last edited by Barry Anderson on Tue May 31, 2016 3:33 pm, edited 1 time in total.
Barry Anderson
Anderson Custom Woodwork, Inc.

sharkcutup
Posts: 408
Joined: Tue Mar 08, 2016 5:23 pm

Re: Vacuum grounding

Post by sharkcutup »

http://www.rockler.com/dust-grounding-kit and http://go.rockler.com/tech/18003.pdf

You might want to check out the above!

I have done same as the .pdf shows with my vacuum system (6.0 hp shop vac and hoses). I bought the stranded wire, connectors, grounding rod (2 foot of #4 rebar) and wire grounding clamp from my local hardware and have not noticed any static since.


Have a GREAT DAY!!! :D

Be SAFE around those AWESOME machines!!! ;)
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Rando
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Re: Vacuum grounding

Post by Rando »

Another couple things to do that helped eliminate static discharges for me:

1) Connect the aluminum bed to the (spindle/router ground) safety ground at the control box by way of a 470K resistor. It's not enough to interfere with the Z-height touch-off circuit, but can bleed off the static charge. Something like this:
Static-drain wire for Shark CNC machines
Static-drain wire for Shark CNC machines
For anyone who isn't able to get hold of that one 470K resistor, I can cheaply make one up for you and ship it out: http://thomr.com/2016/05/solve-static-i ... -machines/.

2) When you clean the machine, include some anti-static wipes/spray in the process, especially over the plastic parts. Something like these:

http://www.amazon.com/s/?ie=UTF8&keywor ... atic+spray

Regards,

Thom
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

Barry Anderson
Posts: 52
Joined: Sun Dec 21, 2014 9:55 pm

Re: Vacuum grounding

Post by Barry Anderson »

Thanks for these replies.
Thom: As I stated in my original post, I think the static electricity may be causing me to lose the controller boards and one computer. I feel it when I am using the shop vac when cleaning the spoil board between cuts. Would your wire/resistor correct this?
Thanks
Barry
Barry Anderson
Anderson Custom Woodwork, Inc.

rsetina
Posts: 213
Joined: Sat May 04, 2013 5:05 pm

Re: Vacuum grounding

Post by rsetina »

I. Ought a grounded hose from Rockler. It seems to work fine.
Rick

Rando
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Re: Vacuum grounding

Post by Rando »

Barry Anderson wrote:Thanks for these replies.
Thom: As I stated in my original post, I think the static electricity may be causing me to lose the controller boards and one computer. I feel it when I am using the shop vac when cleaning the spoil board between cuts. Would your wire/resistor correct this?
Thanks
Barry
If you're seeing static build up on the bed and/or gantry, like you get a big shock every time you get close to the machine after it's been running a while, then yet it would help. It certainly did for me, I haven't had a single shock since I put it on, and no controller problems that I'd trace to it.

Regards,

Thom
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

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bill z
Posts: 342
Joined: Fri Sep 25, 2015 9:09 am
Location: Spring, Texas USA

Re: Vacuum grounding

Post by bill z »

Static build up can be fun. When I was young, both the next door neighbor girl and I wore braces on our teeth. We would run across the carpet dragging our feet and kiss to see the sparks fly.

sharkcutup
Posts: 408
Joined: Tue Mar 08, 2016 5:23 pm

Re: Vacuum grounding

Post by sharkcutup »

I do not believe your static-drain wire would be beneficial in my situation because I am using a water-cooled spindle with power inverter which is not plugged into the control box.

The water-cooled spindle with power inverter power cord is plugged into an "emergency cutoff" switch along with power cord of CNC control box; "emergency cutoff" switch is thereby plugged into a surge trap along with computer, water pump thereby plugged into wall outlet.

With my installed "emergency cutoff" I have control over both router/spindle and CNC control box system in an emergency situation. The e-stop on the control box/control panel screen only stops the CNC movement but does not control the water-cooled spindle power because it is not plugged into the control box (NWA has not implemented the water-cooled spindle into its control box system yet - only electrical powered routers).

On a POSITIVE note I kinda like the separation. I have control of the spindle speed (rpm) at the power inverter for the water-cooled spindle. I can also set my V-Carve Pro programs with faster than normal feed rate (IPM) and during an actual program run I can slow down feed rate if need be by using the percentage slider on control panel screen thereby achieving an acceptable speed/feed rate (rpm/fr). I have used this combo in several instances where there were signs of chatter/burning etc...

Have a GREAT DAY!!! :D

Be SAFE around those AWESOME machines!!! ;)
V-Carve Pro Tips, Gadget Tips & Videos
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V-Carve Pro 11.554

Rando
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Re: Vacuum grounding

Post by Rando »

Sure it will! I have the same setup. There are four wires going to the spindle from the VFD. The spindle motor is wired in a "Y" configuration; it's not like a stepper motor with two independent coils. One of those four wires is actually a ground wire that connects directly to the spindle case and rotor. Surely you're not interrupting the ground wire with your cutoff switch, are you? You're the one always saying to be safe, and it is decidedly NOT safe to disconnect the SAFETY ground to a plugged in, but turned off motor. The VFD I have is a three-wire, single-phase 208/240VAC circuit. The (electrically) center wire is the neutral of the circuit, and the other two are each 120VAC (when referenced to that neutral), but they are two halves of the same phase. This is not the same as true three-phase wiring. The electrical box still needs to be grounded, just like any other electrical box. That safety ground is tied to the neutral wire back at the panel.
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

sharkcutup
Posts: 408
Joined: Tue Mar 08, 2016 5:23 pm

Re: Vacuum grounding

Post by sharkcutup »

Surely you're not interrupting the ground wire with your cutoff switch, are you? You're the one always saying to be safe, and it is decidedly NOT safe to disconnect the SAFETY ground to a plugged in, but turned off motor.
No the Ground Wire is still present and functioning on the emergency cutoff switch!

Have a GREAT DAY!!! :D

Be SAFE around those AWESOME machines!!! ;)
V-Carve Pro Tips, Gadget Tips & Videos
YouTube Channel - Sharkcutup CNC
V-Carve Pro 11.554

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