I have a question about the dust collection system that I am setting up in my house.
I am running some 2-inch PVC pipe in the walls down to the basement where my dust collection with be located.
I have been told to be really careful because of the static and was told that I have to put a good ground on it.
Has anyone else done this, if so, how did you ground the PVC pipe.
Can I just wrap some copper wire around a section of the PVC piping and put it to the ground wire in one of the outlets?
Hi Rick,
I have a 2" flex hose system on my 5pro. You will hear a great deal of noise about needing to ground the pipe to prevent static arcs causing fire. A little bit of research will show that this is not a real concern.
However, whenever air moves over an insulating surface, it will create a high differential voltage that will give a nasty shock, OR if the potential gets high enough, it could arc to the frame of the CNC. This is generally not an issue, but it can cause damage to the electronics or a loss of communication.
I grounded the wire inside the flex hose and I wrapped some copper braided wire around the 4" pipes to the vacuum blower and connected it to ground.
I hope this helps.
Ron Wensley
Now, I wonder if I should return the 2" PVC and order some flex hose.
Would flex hose be better at running down to the basements rather than use PVC?
The folks who sell PVC pipes argue that it can be used thus:
and I’ve seen a fair number of shops so outfitted (but grounded as described by @RonDells ), though usually w/ larger diameter — will this work airflow-wise?
Will,
Air flow is not inturrupted as the copper braid is wrapped around the outside of the PVC and fastened using self tapping screws #6x1/2". As the flex hose already has a wire inside, there is no reason to add more. Just connect the hose wire to the copper braid.
Rick,
No, you want as little flex as you can. Mine is about 10’ due to installation constraints.
With PVC, the friction loss is much lower. Better dust collection is the result.
Mine will be a 20’ run of PVC down to the cellar. I don’t think that would be good to use flex tubing.
My major concern is static charges.
From everything that I have read they say to wrap the PVC with cooper wire. That I can do, and I will wrap it very well just to keep my machine, house, and my butt safe from static and fire. I do not want to take any chances.
If I get 100 feet of 16-gauge copper that should be about 50 wraps around the 20 feet of PVC. I am guessing that would be a wrap about every 5 inches.
Do you think 16-gauge cooper wrapped every 5 inches would be plenty?
Here is the wire I am referring to.
16 Gauge wire
Rick,
That is WAY too much. All you need is about 1 turn every 2 feet or so. It is not that critical.
I will take a picture of my setup in the morning and post it here.
I just wanted to be cautious because this is a 200-year-old farmhouse, and we are the 7th generation to live in it. If something were to ever happen, I would never forgive myself.
I still want to see your pictures, please.
Rick,
You can see the copper wire wrapped around the pipe. Secured with screws at joints with a turn of slack in the wire incase I need to split the joint.
At the machine end of the 4" I have a magnetic couple and can swap out other tools as needed.
The battery alligator clip was what I had on hand,
I use a mix of PVC pipe and semiconductive antistatic flex hose in my extraction. About 1.5m of flex to the machine and about 5m of solid 60mm PVC back to the vortex settler, with a couple of bends and fittings. I find the threaded union fittings very handy to allow disassembly and adjustment of angles etc.
To avoid loss of airflow it’s preferable to minimise the amount of flexible hose as the corrugated wall creates turbulence in the air flow and substantial pressure drop which will reduce your air flow volume, by how much depends upon the fan of your extractor, but a decent rule of thumb is the same loss in 1 foot of flex as 5 feet of straight smooth walled solid pipe.
As others have said, a single conductor to ground the steel wire in the antistatic flex hose with some connection to ground is fine. The PVC pipe is where charge can build up. This is driven by the air and dust particle flow within the pipe, so placing a conductor to bleed away charge on the outside of the pipe is limited in what it can achieve.
Some folks put a solid core copper wire down the inside of the solid pipe to supply an internal discharge path for the air and dust stream. If the charge on the inside of the pipe is managed then there’s less to attract the opposite charge on the outside of the pipe.
For longer runs of solid pipe, for tidiness you could consider using an adhesive copper tape such as this
https://www.amazon.co.uk/Premium-Adhesive-Copper-Foil-Tape/dp/B07CSGWJH7/
This could be stuck inside or outside and neatly stay out of the way.
Remember that any of these conducturs need a path to ground or they’re simply helping spread the problem. You don’t need to worry about a high current or low resistance path, this is static electricity, you just need a path for charge to bleed away to stop it accumulating.
Edit - just to clarify, I’ve used this setup a fair amount, with only the flex pipe grounded with no issues, but I’m in the wet UK, not the US midwest with really low outdoor humidity where the static issues really get bad.
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