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I can't spend too much time explaining as my mother passed away on Sunday but I can tell you my system piped in all 6" pipe can take a 25' rule from any outlet and suck that baby back to the DC unit without issue. So how much do you really need or want? As for static the only machine I notice any feedback is my spiral head planner. I will be running bare copper around my lines and outlets to a ground source later on. I'll also say my basement shop stays about 68-70 degrees and maybe 40-50% RH.
 

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I can't spend too much time explaining as my mother passed away on Sunday but I can tell you my system piped in all 6" pipe can take a 25' rule from any outlet and suck that baby back to the DC unit without issue. So how much do you really need or want? As for static the only machine I notice any feedback is my spiral head planner. I will be running bare copper around my lines and outlets to a ground source later on. I'll also say my basement shop stays about 68-70 degrees and maybe 40-50% RH.

Sorry to hear about your mother, Steve. My condolences to you and your family.
 
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Sorry to hear about your mom, Steve.
Hearts to you and your family....
 

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Hey guys , this gets more complicated. This guy made a comment on youtube , and is claiming that 4” is better for vertical drops , as the velocity is faster .
I was going to run 6” pvc trunk , and go with 6” all the way to the table saw.

Rick...a 4" line will do...but not because it's better than a 6" drop. A table saw typically requires about 400CFM. At full flow (4500FPM) a 4" line will pass about 400CFM. At the same velocity, a 6" line will pass close to 900CFM. But only if the table saw allows replacement air to allow the duct full velocity. If not, no matter how big the duct, you won't get any more flow. Remember, everything downstream of the DC impeller is a restriction to the DC. You are considering all the bends in the main duct...consider also making sure the TS allows for replacement air. DC's don't allow more flow on suction (vacuum), they work on velocity allowed in the whole system. When you run your drop to your router table with a 2 1/2" hole at the table, for example, it will only allow about 200CFM...but only if you allow sufficient replacement air. If you don't allow for full flow, you'll likely accumulate chips and dust in the main duct. In order for chips and dust to make it all the way to the DC you will need velocity to carry them. Any change in velocity will cause chips and dust to drop at the change. That's how a separator works...air changes direction and/or velocity and gravity takes over.

Look up some flow tables and that will help you determine duct sizes for each machine...and totaling the flow requirements if you're going to run more than one machine at a time. An example might be running your CNC for several hours while you work on another project on your table saw or router.
 

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If you are only using a machine like a router table with a 2 1/2" port then you may improve it's flow by opening another port that is upstream from that one. The force of the air going past the 2 1/2" connection will act like the throat of a carburetor and create more vacuum at the mouth of the 2 1/2" port but only to a point.

Another factor that needs to be considered is the air volume in the pipe. If your main is 6" and you only have a 2 1/2" port open then there may not be enough air volume in the pipe to float the heaviest debris along it. It has to stay suspended in the air to make it to the DC and if there is very little air in the pipe then it may not happen. An example of this is if you hold a ping pong ball in your hand and then put a vac hose tight against your palm and start the vac up. The ping pong ball doesn't go anywhere because there is no air movement in the pipe.

Most people probably don't understand what is actually happening when the DC is turned on but what the impeller is doing is taking the air against it and propelling it out of the system to atmosphere. That leaves a void so atmospheric pressure pushes in to fill that void at the force of 14.7 pounds per square inch. There is no way to increase that force so the only thing you can do to improve the system is to move more air out of it more quickly. But as Nick said, you can only move so much through a 2 1/2" hole no matter what you do because you are limited with that 14.7 lb/square inch input force.
 

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Discussion Starter · #26 ·
I can't spend too much time explaining as my mother passed away on Sunday but I can tell you my system piped in all 6" pipe can take a 25' rule from any outlet and suck that baby back to the DC unit without issue. So how much do you really need or want? As for static the only machine I notice any feedback is my spiral head planner. I will be running bare copper around my lines and outlets to a ground source later on. I'll also say my basement shop stays about 68-70 degrees and maybe 40-50% RH.
Sorry to hear about your Mom Steve
 

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Discussion Starter · #27 · (Edited)
Rick...grounding dust collection PVC is like having a torque wrench...you don't use it every day and it sits in a drawer but it's there when you need it...

Read this article...there are lots more articles to read...search "grounding dust collection systems" https://www.thegeekpub.com/3621/grounding-a-dust-collection-system/

...ever see the sign at gas pumps warning you about getting in and out of your car while pumping gas...? And to touch a metal part of the vehicle before reaching for the pump handle...? Anytime anything moves through a container it has the capacity of creating and storing static electricity...an unwanted discharge may have consequences...

...YMMV...
It has me concerned,but it sure looks like crap lol. Guess I gotta do it regardless.
I’m amazed a screw connected to ground going threw the duct is enough to actually dissipate any static electricity .
Have to do some more research.

I’ve also heard you should have a copper wire running inside the duct . Makes more sense , but would certainly speed up getting plugged duct work
 

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It has me concerned,but it sure looks like crap lol. Guess I gotta do it regardless.
I’m amazed a screw connected to ground going threw the duct is enough to actually dissipate any static electricity .
Have to do some more research.

I’ve also heard you should have a copper wire running inside the duct . Makes more sense , but would certainly speed up getting plugged duct work
Which is why I went with metal piping. I drilled the pipe in a few places and put the bolt head on the inside and then double nutted the outside with the ground wire sandwiched between the nuts. I don't know if I even needed the ground wire with metal pipes but it's a case of more is better. I live in the boonies so fires are a big issue with me.
 

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The Home shop Dc systems do not generate enough static Electricity to cause a spark, I have read. These are not sawdust silos at the mill or grain silos . There are lots of articles written about how static electricity is formed inside of duct work. Home Dc's are run for short periods and off for longer periods.

Rick, don't even think of smaller than 6" duct, that is why you are buying such a powerful set up, take full advantage of it. Hook the 6" up to your TS and any other machine that will take it. Do like Nick said don't cover the spaces between the table and the saw base, you need that for make-up air to get the full capacity out of your system.

Steve, sorry about you Mom, condolences to you and your family.
HErb
 

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Discussion Starter · #30 · (Edited)
Which is why I went with metal piping. I drilled the pipe in a few places and put the bolt head on the inside and then double nutted the outside with the ground wire sandwiched between the nuts. I don't know if I even needed the ground wire with metal pipes but it's a case of more is better. I live in the boonies so fires are a big issue with me.
I’d have to make trips to Calgary, as there’s no metal duct herd unless it’s flimsy furnace duct .
There is a wholesaler here for irrigation stuff, and they were kind enough to give me contractors rate on pvc pipe , which will save me a ton .
Ken ( the cyclone dealer in Calgary) does have a recommendation for a company in Calgary that sells metal pipe .
I could bring my trailer and do it all at once, but I really prefer the PVC


The Home shop Dc systems do not generate enough static Electricity to cause a spark, I have read. These are not sawdust silos at the mill or grain silos . There are lots of articles written about how static electricity is formed inside of duct work. Home Dc's are run for short periods and off for longer periods.

Rick, don't even think of smaller than 6" duct, that is why you are buying such a powerful set up, take full advantage of it. Hook the 6" up to your TS and any other machine that will take it. Do like Nick said don't cover the spaces between the table and the saw base, you need that for make-up air to get the full capacity out of your system.

HErb
I’m with you Herb, as static issues are probably much more prone to industries where there moving 50,000 cfm , and the saw dust is moving 200 mph .

But I’m debating to drill small holes , and installing one copper wire stretched tightly inside the top of the closest duct in the DC run , and grounding it to a receptacle for piece of mind .
 

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Rick, a lot of guys install the PVC with the purple primer and glue, I just stuck mine together with nothing and used that metal duct tape to seal the around the joint to seal it. That way in the future, I can reroute the ducts anyway I want, if I decide to move or replace a machine.
HErb
 

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Discussion Starter · #32 · (Edited)
Rick, a lot of guys install the PVC with the purple primer and glue, I just stuck mine together with nothing and used that metal duct tape to seal the around the joint to seal it. That way in the future, I can reroute the ducts anyway I want, if I decide to move or replace a machine.
HErb
The video I posted shows the guy using silicone tape around the joints , plus screws on the vertical drops . That way he can make changes in the future if necessary.
Glad I seen that , because otherwise I wound have glued the joints and been in a place of no return . So I certainly appreciate you mentioning it also .

Talks about the tape around 10:40

I’m not sure which tape he used exactly, but I googled it and found this stuff at our local Canadian Tire
 

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Discussion Starter · #34 · (Edited)
I used aluminum foil duct tape, like this SureTape from HD.
https://www.homedepot.com/p/Shurtape-1-88-in-x-10-yds-Aluminum-Foil-Repair-Tape-241588/301296783

Sheet metal screws,one each side on the vertical and hrorizontal run before tape.

https://www.lowes.com/pd/Blue-Hawk-...-Interior-Exterior-Sheet-Metal-Screws/4634685

HErb
Herb I think metal foil tape is the winner , and I still have some here left over from other projects.
I wasn’t paying attention to the cost of that silicone tape .
About $15.00 after tax , and that gets you a total of 10’ . So $1.50 a foot for tape?
That’s almost what I’m paying for the 6” duct . No thanks Jeff
 

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Discussion Starter · #35 ·
Well things have gone up . Last time my electrician installed a twist lock 30amp 240v receptacle , the male end and the receptacle were $109 for the pair . Now the receptacle alone is over $150 , and this is contractor rates .
Imagine paying over $200 for every 240V receptacle?

I think the twist lock will only be used for the DC and overhead plug on the table saw
 

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Why do you need Twist locks? For a large motor like the DC I have mag starter and disconnect and the motor is wired direct to the mag starter. It t is wired for a remote lapel control so I can start/stop it from anywhere in the shop.
HErb
 

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Discussion Starter · #37 · (Edited)
Why do you need Twist locks? For a large motor like the DC I have mag starter and disconnect and the motor is wired direct to the mag starter. It t is wired for a remote lapel control so I can start/stop it from anywhere in the shop.
HErb
I was concerned about vibration. Of course seeing as the power to the table saw will be mounted on the ceiling , twist kicks would make sense .
But it’s more than likely overkill on the DC .

I was going to use a twist lock on the cnc spindle though . Just for piece of mind , and because I have two.

Edit . Herb , almost forgot , the DC will be controlled by an IVAC system . The control box for the IVAC goes to a contactor in a separate enclose that will be plugged into the wall with a twist lock .
I tried the IVAC without an external contactor , and it kept on tripping its breaker because of the inrush current

 

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It is a good idea to hook that Ivac up to the shop light circuit so that when you leave the shop and turn off the lights,it kills the DC circuit.then there is no chance that it will turn on by itself and run while you are not there. That is the way the electrician hooked up mine. Or some other type of way to kill the power to the shop when you are not there. Some switch that is located near the exit.
HErb
 

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I can't remember where I got this article on grounding PVC. If it came from someone on this forum, I apologize for not being able to identify you.

WoodCentral Articles & Reviews

I personally have metal (Nordfab) with a vertical 6" run that splits (Y) to individually gated 4" runs to table saw and jointer. I have never noticed any saw dust accumulation at the entrance to the 6" section.

You can't generalize from my system to yours because system performance is determined by a combination of the ducting and blower. From an engineering perspective, calculating overall system performance is a difficult problem. We know how to calculate pressure drop in straight sections, elbows and other common fittings. The other piece of the puzzle is the pressure drop from the throat plate on the table saw to the inlet to the piping. This information is generally unknown. The same thing applies to all the other shop tools connected to the dust collector. Hopefully your blower manufacturer can give you some guidance based on their experience.
 

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Discussion Starter · #40 · (Edited)
Why do you need Twist locks? For a large motor like the DC I have mag starter and disconnect and the motor is wired direct to the mag starter. It t is wired for a remote lapel control so I can start/stop it from anywhere in the shop.
HErb
Something like this Herb. This was put in for the laser engraver so I could kill power to it , but I think I’ll dedicate it to the DC ;)
 

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