Shop Vac dust collection

[Elmo Sr]

I have been told that i should not use a vacuum cleaner to vacuum out the Carvewright because of static electricity, but if I use the dust collection hood can I attachment to the shop-vac? I do need to set up some kind of dust collection system especially when I do a 3 plus hour carve.

Also if I use my 45* bit on what kind of spacer do i need to use, can I just buy a plastic type from a box store as long as it fits my 1/2" shank bit stainless steel shaft carbide tips?

Thanks
Elmo

[SteveNelson46]

I have been told that i should not use a vacuum cleaner to vacuum out the Carvewright because of static electricity, but if I use the dust collection hood can I attachment to the shop-vac? I do need to set up some kind of dust collection system especially when I do a 3 plus hour carve.

Also if I use my 45* bit on what kind of spacer do i need to use, can I just buy a plastic type from a box store as long as it fits my 1/2" shank bit stainless steel shaft carbide tips?

Thanks
Elmo

You can use a shop vac for dust collection and for cleanup but, compressed air works better for cleanup. Just make sure the vacuum is grounded and the Carvewright is grounded. The reason most recommendations are against a shop vac for a dust collector is that most vacuums are not rated for continuous use and the motor burns up if left on for an extended time.

[Elmo Sr]

Thank you Steve for this info, I will just be sure I keep an eye on shop-vac until I can git enough coins for a real dust collector.

[fwharris]

Although not recommended as Steve stated some do use the shop vac for dust collection. Static grounding is a must have as the air moves at a much higher volume making it more prone to static build up. You will also find that the filter in the shop vac will plug up quickly and will need to be cleaned very frequently. Getting a real dust collector, even one of the small portable units, would be your better option.

For your 45* bit you should be able to use the 1/2" plastic tube fitting as a bit stop.

[SteveNelson46]

Also if I use my 45* bit on what kind of spacer do i need to use, can I just buy a plastic type from a box store as long as it fits my 1/2" shank bit stainless steel shaft carbide tips?

Thanks
Elmo

The stop collars that Carvewright sells are just 1/4" and 1/2" plastic (fish tank) tubing and you can buy it at most hardware stores and cut it to length. I have found that they can sometimes get hot and can be compressed more easily than when they are cold. I use steel stop collars designed for high speed routers that are tightened with a set screw. Here is a link

http://www.routerbitworld.com/category-s/2116.htm (http://www.routerbitworld.com/category-s/2116.htm)

[dltccf]

The stop collars that Carvewright sells are just 1/4" and 1/2" plastic (fish tank) tubing and you can buy it at most hardware stores and cut it to length. I have found that they can sometimes get hot and can be compressed more easily than when they are cold. I use steel stop collars designed for high speed routers that are tightened with a set screw. Here is a link

http://www.routerbitworld.com/category-s/2116.htm (http://www.routerbitworld.com/category-s/2116.htm)

Thanks for the link to the stop collars, I was just thinking about finally getting some.

dave

[kcc2012]

How do you ground the shop vac and the carvewright?

[fwharris]

How do you ground the shop vac and the carvewright?

If you do not have a static ground system in your shop already then you can add a grounding lead to the green terminal (ground) of the outlet you have your shop vac plugged into. From that lead coil the wire around the shop vac hose up to the machine. Use alligator clips for ease of attachment and removal.

Make sure you power down before making the connection in the outlet box.

[SteveNelson46]

How do you ground the shop vac and the carvewright?

There are many methods that have been discussed here on the forum. Almost all of the will work. Basically, you just need to attach a wire from the machine to a ground source. Use Floyds DC screw mounts as it is metal and works really well. Do the same with your shop-vac. You can ground them separately or together. Some like to wrap the hose with the wire. Some use the metal coil in the hose as the wire. It really doesn't matter as long as both are connected to a good ground source.

[mazing]

I've used the same CMT stop collars on other tools/routers before I got the cnc bug. I've always got them from 2 sources with great prices depending on the quantity I was purchasing: Baird's and AceTools. I had to go check to make sure they were still being offered and they are. Baird's has them for $3.50 each, but shipping is always rather high ($20 or so an order), AceTools has them for a buck more, $4.50 each, but offers USPS shipping for around $6. So like I mentioned, depending on the quantity you are ordering, one will work out to be the better deal. Baird's: http://www.bairdbrothers.com/CMT-Bearings-C5853.aspx, AceTools: http://www.acetoolonline.com/CMT-Accessories-s/4457.htm - the stop collars on at the bottom of the page.

Mike

[Elmo Sr]

I want to say thank you to all you folks that help me, and to say I appreciate this place and the helpfulness everyone displays.

Thanks
ElmoSr

[Digitalwoodshop]

The dust moving through the machine vac hose is what causes the static charge to build up.

AL

[mcQ]

I agree with Floyd a shop vac is more prone to static buildup than a dust collector due to the smaller hose and higher velocity.
However, to be effective a bare copper ground wire needs to run through the hose where it is in contact with the moving dust particles to be effective. Wrapping the wire around the outside of the hose won't be as effective because the plastic hose
insulates the wire from contact with the dust. The instructions for any of the grounding systems say to run bare copper wire through the hose.

[DickB]

However, to be effective a bare copper ground wire needs to run through the hose where it is in contact with the moving dust particles to be effective. Wrapping the wire around the outside of the hose won't be as effective because the plastic hose
insulates the wire from contact with the dust. The instructions for any of the grounding systems say to run bare copper wire through the hose.
I don't agree. Charge builds on non-conductive duct when the moving dust contacts the duct. No significant charge collects on the dust itself, and if it did clearly most dust particles would not come in contact with a single wire inside PVC and would remain charged. A single wire, inside or out, would not effectively dissipate static from the PVC.

From airhand.com:

The following is from NFPA Code Booklet #664, section A-8-2.5.5. To obtain a copy contact: National Fire Protection Agency, Quincy, MA (617) 770-3000. It states in reference to Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities:

"Nonconductive ducts, such as PVC pipe, should not be used. A ground wire or other grounding system for PVC pipe is not acceptable."

A proper flexible hose can be used and be well grounded via the reinforcing wire:
http://www.flexaust.com/wp_super_faq/ground-dust-collection-hose/

[200k]

Static and dust collection has been discussed in this forum and every woodworking forum on the internet since Al Gore invented it. ;-) I have read tens of thousand of words on the subject but I just recently came across what I feel is the absolute best article addressing the subject. It covers the entire subject from a scientific point of view plus it cites specific real-world conditions. I for one am satisfied that no more discussion is needed. The link to the article entitled "Grounding PVC and Other Dust Collection Myths" is here: http://home.comcast.net/~rodec/woodworking/articles/DC_myths.html

Subject closed. (I hope.)

200k

You'll notice I didn't declare any conclusions, did I? ;) Make your own judgments after reading the article.

[200k]

Okay, you'll notice that just after declaring the final answer to dust collection system static I will now ask the question: Will the CarveWright machine itself benefit from extra grounding to stop static cling? I would think the ground on the power plug should be sufficient in that, at least in theory, all metal parts of the machine are connected to that ground, if for no other reason than to protect the electronics from static discharge. BUT, I still get tons of little white flecks clinging everywhere to the inside of the machine every time I cut Lexan; and that's with a serious dust collection system going. (RingNeck Blues) Will running a copper wire from a mounting screw on the RingNeck DC to a bolt in my concrete slab floor help anything?

200k

[DickB]

The Carvewright's metal parts are not grounded through the power plug. Many recommend grounding the metal parts to avoid static discharge causing electrical damage. Speaking from experience - my machine is externally grounded - I don't think it will help with "static cling".

[fwharris]

I do not think anything will/can prevent the acrylic/corain chips and dust from clinging to the inside of the machine. I've tried the dryer sheets trick of wiping down the inside of the machine and IMO it did very little.

I've also read a lot on the subject of PVC pipe for ducting in dust collection systems. Basically all said they are not suited for wood shops and no matter how you set up your grounding system they do not prevent static build up.

[mcQ]

The requirement for the wire to run inside the hose comes from the instructions from any of the ground kits sold by dust collection manufactures.
Below is the instruction sheet from Rockler, highlighted note a bare wire must run internally through the ducts and hose. Additional static suppression may
be accomplished by also wrapping a wire around the outside.

67978

[mcQ]

This NFPA code only applies to commercial manufactures, most home shops use PVC ductwork or just directly attach a plastic hose from the dust collector to the machine.



I don't agree. Charge builds on non-conductive duct when the moving dust contacts the duct. No significant charge collects on the dust itself, and if it did clearly most dust particles would not come in contact with a single wire inside PVC and would remain charged. A single wire, inside or out, would not effectively dissipate static from the PVC.

From airhand.com:
The following is from NFPA Code Booklet #664, section A-8-2.5.5. To obtain a copy contact: National Fire Protection Agency, Quincy, MA (617) 770-3000. It states in reference to Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities:

"Nonconductive ducts, such as PVC pipe, should not be used. A ground wire or other grounding system for PVC pipe is not acceptable."

A proper flexible hose can be used and be well grounded via the reinforcing wire:
http://www.flexaust.com/wp_super_faq/ground-dust-collection-hose/

[DickB]

Perhaps it would be best to first concentrate on the configuration that started this thread: a shop vac connected to a Carvewright. I myself strayed away from that with the reference to PVC - sorry.

I suggest that there are three reasons to consider grounding:


Equipment damage: prevention of ESD (electrostatic discharge) damage, particularly to the Carvewright.
Safety: prevention of fire or explosion.
Comfort: prevention of a static shock to one's person.

Anyone who has used a shop vac to collect sawdust can attest that static electricity is generated. This is caused by the sawdust particles moving through the shop vac hose.

Regarding point 1, static charge collecting on the hose can be transferred to the Carvewright. Sawdust moving within the Carvewight itself may also generate a static charge. Without additional grounding, charge can accumulate since the ground on the power plug is not electrically connected to the machine's metal frame and head. An external ground wire added to the machine and/or head can provide a path for static charge to be dissipated, reducing the chance of a damaging ESD event to the machine. This would I suggest include an externally-induced charge, such as when opening the cover to change bits, even if no vacuum system were employed.

There have been anecdotal reports on this forum of users who have experienced electronics failures of their Carvewright machines using ungrounded shop vac setups, and those who have experienced no failures using the same setup. This does not surprise me. However, static electricity is definitely generated in the shop vac hose. In my view, grounding the Carvewright to drain off any potential static charge is a wise preventative move.

Now on point 2, I do not believe that there is a significant risk of explosion or fire in using a shop vac. Millions are sold and in use, connected to other equipment or not, and incidences are rare - I don't believe that I've ever heard of one. If it were necessary for shop vacs and hoses to be grounded for safety reasons, certainly manufacturers would do that. If you read 200k's reference, it also comes to the conclusion that the use of PVC does not present a significant safety risk.

On point 3, 200k's reference suggest that this is the reason to run a ground wire inside the hose or PVC. I'll not repeat the reasoning here, but note that it is argued that an internal ground wire does not eliminate static charge, but rather provides a shorter path to ground for an electrical discharge, making contact with a spark less uncomfortable. Again, back to the shop vac application, due to the length of hose, an internal ground wire is probably not required for comfort reasons.

I understand that the code that I cited does not apply to home shops. I did not intend to imply that it does, sorry for any confusion. I intended only to cite it as a reference regarding the effectiveness of a bare copper wire in a PVC pipe in eliminating static discharge. I believe it not recommended in large commercial applications because it is not effective at eliminating static charge under conditions where explosion may be possible.

In any case, the statement that a bare copper ground wire needs to run through the hose where it is in contact with the moving dust particles to be effective is not technically accurate, and that was meant to be the gist of my earlier post.

[fwharris]

Perhaps it would be best to first concentrate on the configuration that started this thread: a shop vac connected to a Carvewright. I myself strayed away from that with the reference to PVC - sorry.

I suggest that there are three reasons to consider grounding:


Equipment damage: prevention of ESD (electrostatic discharge) damage, particularly to the Carvewright.
Safety: prevention of fire or explosion.
Comfort: prevention of a static shock to one's person.

Anyone who has used a shop vac to collect sawdust can attest that static electricity is generated. This is caused by the sawdust particles moving through the shop vac hose.

Regarding point 1, static charge collecting on the hose can be transferred to the Carvewright. Sawdust moving within the Carvewight itself may also generate a static charge. Without additional grounding, charge can accumulate since the ground on the power plug is not electrically connected to the machine's metal frame and head. An external ground wire added to the machine and/or head can provide a path for static charge to be dissipated, reducing the chance of a damaging ESD event to the machine. This would I suggest include an externally-induced charge, such as when opening the cover to change bits, even if no vacuum system were employed.

There have been anecdotal reports on this forum of users who have experienced electronics failures of their Carvewright machines using ungrounded shop vac setups, and those who have experienced no failures using the same setup. This does not surprise me. However, static electricity is definitely generated in the shop vac hose. In my view, grounding the Carvewright to drain off any potential static charge is a wise preventative move.

Now on point 2, I do not believe that there is a significant risk of explosion or fire in using a shop vac. Millions are sold and in use, connected to other equipment or not, and incidences are rare - I don't believe that I've ever heard of one. If it were necessary for shop vacs and hoses to be grounded for safety reasons, certainly manufacturers would do that. If you read 200k's reference, it also comes to the conclusion that the use of PVC does not present a significant safety risk.

On point 3, 200k's reference suggest that this is the reason to run a ground wire inside the hose or PVC. I'll not repeat the reasoning here, but note that it is argued that an internal ground wire does not eliminate static charge, but rather provides a shorter path to ground for an electrical discharge, making contact with a spark less uncomfortable. Again, back to the shop vac application, due to the length of hose, an internal ground wire is probably not required for comfort reasons.

I understand that the code that I cited does not apply to home shops. I did not intend to imply that it does, sorry for any confusion. I intended only to cite it as a reference regarding the effectiveness of a bare copper wire in a PVC pipe in eliminating static discharge. I believe it not recommended in large commercial applications because it is not effective at eliminating static charge under conditions where explosion may be possible.

In any case, the statement that a bare copper ground wire needs to run through the hose where it is in contact with the moving dust particles to be effective is not technically accurate, and that was meant to be the gist of my earlier post.

Dick,
Very well stated sir!

[mcQ]

The fact that to be effective a bare wire needs to run through the duct work and hose did not just come from me.
Every ground kit sold whether from Rockler, Shop Fox, Grizzly, Woodcraft all have instructions that the wire must run through the hose and duck work to be effective.
See the attached instruction sheet I copied from Rocklers site and posted earlier today.
I would trust that the companies manufacturing and selling dust collection equipment including the ground kits are more knowledgeable than most of us.
Why not just follow these manufactures instructions running the wire inside and if you want go ahead and also wrap the outside for extra insurance.

[DickB]

We seem to be repeating ourselves. I'm not arguing that the aforementioned grounding kits are not effective at reducing static discharges to the person. I am asserting that they are not necessary or effective for explosion or fire reasons. I am also asserting that they do not work on the principle of dust particles coming in contact with the copper wire.

[mcQ]

Regardless of how the ground works they are effective at reducing static discharges to both a person as well as the CarveWright machine and because of this are a good precaution to prevent damage from static.
Also, I see no reason not to install the ground kit per the instructions included in the kit.