# Dust collection Q/A......



## GorillaWood (Dec 30, 2010)

Let me take a minute to first say hello, and thank you all for the mountins of information I have received from this site.

This is my first post, my name is Eric and I am located in Huntington Beach, So. California. I love woodworking.

Ok so now that is out of the way on to my dust dilemma. I came up on a "Delta 50-850" 1200 cfm, single can dust collector for almost nothing and would like to implement it into my small shop. It currently has 2, 5 micron filter bags on it. 

I would like to add a two stage system and switch out to a 1 micron felt filter on top and a plastic bag for the dust collection the bottom. 

Any ideas on the CFM loss for these mods. Or a formula to figure it out.

Thanks-
Eric
Gorilla Woodworking


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> Let me take a minute to first say hello, and thank you all for the mountins of information I have received from this site.
> 
> This is my first post, my name is Eric and I am located in Huntington Beach, So. California. I love woodworking.
> 
> ...


Welcome to the forum. Your question has been asked and debated several times in one way or another on here. This is my thought, and one of my up cumming projects after I get back from vacation.

Many machines use the plastic bag on the bottom and a filter bag on top. 1 micron is better of course but you could lose some air outflow which could hamper your system. A canister filter on top is better because you get 5-6 times the outflow of air which increases the CFM and they go to .5 or 1 micron filtration. This is the link to a retrofit canister filter. It's a little pricey but not that much more then the bags considering the benefits. Just my opinion.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> Welcome to the forum. Your question has been asked and debated several times in one way or another on here. This is my thought, and one of my up cumming projects after I get back from vacation.
> 
> Many machines use the plastic bag on the bottom and a filter bag on top. 1 micron is better of course but you could lose some air outflow which could hamper your system. A canister filter on top is better because you get 5-6 times the outflow of air which increases the CFM and they go to .5 or 1 micron filtration. This is the link to a retrofit canister filter. It's a little pricey but not that much more then the bags considering the benefits. Just my opinion.


Thanks rrbrown. 

After reviewing the link you sent I feel the extra $$ would be very well spent. They offer a nano canister that filters partials as small as 0.5 microns. Impressive! My lungs thank you.

Does anyone know the approximate CFM increase the canister offers or another link to offer more information. 

Along with my first post, a little more info.... My shop layout requires about 1200 cfm to and I am trying to keep it as close to the original statistics or even boost them, like with a canister. 

Thanks again 
Gorilla


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> Thanks rrbrown.
> 
> After reviewing the link you sent I feel the extra $$ would be very well spent. They offer a nano canister that filters partials as small as 0.5 microns. Impressive! My lungs thank you.
> 
> ...


I think your looking at this the wrong way. I'm guessing your a one man shop and will only operate one machine at a time, if not then you may require 1000 0r 1200 cfm.

This link helps some or maybe this one.

Here are the basic list of CFM needed for each machine
*Machine* *CFM Requirements*  
Table Saw - 10' 350 - 450
Band Saw - 14' 350 - 400 
Jointer - up to 8' wide 350 - 450  
Planer - 12'  500 
Planer -15' and larger  600 - 900  
Disc Sander - 12'  300 - 350  
Horizontal Belt Edge Sander 550 - 600  
Vertical Belt Sander - up to 6' wide 400 - 450  
Drum Thicknessing Sander - up to 12' drum  400 
Drum Thicknessing Sander - 12' - 24' drum  550 
Drill Press  300 
Scroll Saw  300 - 350



You should run the largest duct possible for the main line and for as long a run as you can. Reduce it down to the size for each tool as close to the tool as possible.

I ran 4" throughout and it works pretty good but I'm upgrading to 6" main and the canister filter. I have a homemade chip collector and there is another good thread for one on here.

This is the link.


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## Jackfre (Dec 23, 2009)

*I have that system*

and have been well served with the 1 micron top bag and the felt bag downstairs. When I empty the bottom bag, I drop a garbage bag over top of the felt, roll it upside down and lift the felt bag out. I do it outside and it has been fine. I work on one piece of equipment at a time, moving the 4"flex hose to each piece as I go. The work area is small, it is a pain in the neck and it has worked out very well. It handles my Unisaw, 16" bandsaw, 13 planer and 6" jointer. I also have a JDS 200 filter box for ambient air dust collection. From my experience, I'd do the 1mc and put money into the ambient box or your choice.


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## rrbrown (Feb 15, 2009)

A quick check of how much more air flow a canister filter can create over the bag is remove your filters all together and see how much more suction is at the tool port now. (no need to actually cut anything but check the suction).

It should be quite a big difference and by adding the canister filter you would get closer to the no filter range of airflow. I checked mine as best i could and there is a difference but not as big of one as I thought, but I have 30 micron bags that I thought were 2 micron. However when I removed the 4" y connector at the DC and checked it, it seamed a little more noticeable.

My plan is still to switch to a 6" main line and reduce to 4" at each tool port. I also will get a canister filter. I also plan on finding or making something to test the air flow as is with the canister filter and then again with the larger duct. For now I plan on making a dial indicator that will have a 3" plastic ball attached to a string or wire. If anyone has a better idea about how to test it please let me know.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> I think your looking at this the wrong way. I'm guessing your a one man shop and will only operate one machine at a time, if not then you may require 1000 0r 1200 cfm.
> 
> This link helps some or maybe this one.
> 
> ...


Thanks again. 

I am a one man shop and often run two machines at once. How I mapped out my duck work I require 1125. With automation in the future.But more than that I like to over think and inturn overkill. 

I guess um saying I dont like to do things twice. I am also trying to set up for a possible small two man show. 

I planned on a 6"main leading to a trash can chip collector (modified 55 gallon cardboard drum) then onto the dust collector with a canister (per your recommendation). 
With the delta 850 producing 1200 cfm I have little room for loss of airflow and the collector was the right price of free when I bought my 10" unisaw. I was trying to work with what I have. Hens getting the 0.5 mcr canister. 

To make get back to the topic at hand. I was looking for performance specs of a canister and trash can chip collector ie:
Canister: gain of 25 cfm

Chip collector: a loss of 100 cfm 

Thanks for your correspondance. Very informative. I will dabble and see if I can figure out a cfm gauge idea.

-Gorilla


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> With the delta 850 producing 1200 cfm I have little room for loss of airflow and the collector was the right price of free when I bought my 10" unisaw. I was trying to work with what I have. Hens getting the 0.5 mcr canister.
> 
> To make get back to the topic at hand. I was looking for performance specs of a canister and trash can chip collector ie:
> Canister: gain of 25 cfm
> ...


Last thing is that all these manufacturers manipulate the CFM rating in some way. I have the Shop Fox 1 1/2 hp motor 12" impeller which should be close to the one you have and using a 6" main should support 2 tools at once if you reduce down to 4" just before the tool. Even if this dust collector don't work as well as you would like, it should be good enough until you get a larger unit. (HP and impeller)


I know some where I seen a list of reductions in static pressure for pipe length, elbow, etc but never for CFM. I think it was in my owners manual for my old Craftsman dust collector that the motor crapped out on but I will check. I think I read about reduction from chip collector on line but don't remember where.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> Last thing is that all these manufacturers manipulate the CFM rating in some way. I have the Shop Fox 1 1/2 hp motor 12" impeller which should be close to the one you have and using a 6" main should support 2 tools at once if you reduce down to 4" just before the tool. Even if this dust collector don't work as well as you would like, it should be good enough until you get a larger unit. (HP and impeller)
> 
> I know some where I seen a list of reductions in static pressure for pipe length, elbow, etc but never for CFM. I think it was in my owners manual for my old Craftsman dust collector that the motor crapped out on but I will check. I think I read about reduction from chip collector on line but don't remember where.


I have a .pfd from a dust ductwork distributor with all the information from tool cfm consumption to static pressure calculations. If you would like a copy fortune use. 

On another note. What your opinion on pvc vs galvanized duct?


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> I have a .pfd from a dust ductwork distributor with all the information from tool cfm consumption to static pressure calculations. If you would like a copy fortune use.
> 
> On another note. What your opinion on pvc vs galvanized duct?


I use PVC drain pipe, but that's a whole new can of worms you just opened. The truth is in theory metal is better because of the possible explosian risk. However in commercial and even more likely industrial application but not home use. (In my Opinion) I have asked that if anyone can show proof of a dust explosion in a home shop caused by PVC that I would reconsider it but there has never been proof. I have searched the internet myself and nothing. If you live where it is cold and dry then there may be a small increase in concern but I still don't buy it. If you can afford and want the metal duct then go for it to be safe but I stand by my request for proof, with no response.

Metal duct is required in commercial shops by OSHA.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> I use PVC drain pipe, but that's a whole new can of worms you just opened. The truth is in theory metal is better because of the possible explosian risk. However in commercial and even more likely industrial application but not home use. (In my Opinion) I have asked that if anyone can show proof of a dust explosion in a home shop caused by PVC that I would reconsider it but there has never been proof. I have searched the internet myself and nothing. If you live where it is cold and dry then there may be a small increase in concern but I still don't buy it. If you can afford and want the metal duct then go for it to be safe but I stand by my request for proof, with no response.
> 
> Metal duct is required in commercial shops by OSHA.


That is my opinion as well. Just wanted to hear from someone else with experience. Rather than a website written who knows, who knows when. Now did u get the drain pipe at a big box store ( home depot, lowes) or a plumbing supply house?


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> That is my opinion as well. Just wanted to hear from someone else with experience. Rather than a website written who knows, who knows when. Now did u get the drain pipe at a big box store ( home depot, lowes) or a plumbing supply house?


*
Yes but I didn't run 6" at first. For 6" I have to go to a plumbing supply.* 

*With just 4" pipe it will suck my hand up into the duct with quite a bit of force and that's like 25' past the chip collector and with 3 elbows and a tee in the line. I'm guessing 6" will drastically improve the system.*


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## GorillaWood (Dec 30, 2010)

As per your Osha comment I am well aware of commercial standards.My family has been in furniture frame manufacturing for over 50 years. At work I have a 5 story dust collector that empties into a roll-off dumpster. Horrible efficiency. Let me tell u changing the 25 filters on that baby is an all day chore. I'm just trying to make do at home on a much smaller scale


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> Yes but I didn't run 6" at first. For 6" I have to go to a plumbing supply.
> 
> With just 4" pipe it will suck my hand up into the duct with quite a bit of force and that's like 25' past the chip collector and with 3 elbows and a tee in the line. I'm guessing 6" will drastically improve the system.


That sounds good. If you are going to resize your main I have found an air handling guide pfd to be very helpful. If you would like a copy of it I would be more than happy to share it. It deals with pipe diameter cfm, static pressure guide and calculations if you are trying to make your system more efficient.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> A quick check of how much more air flow a canister filter can create over the bag is remove your filters all together and see how much more suction is at the tool port now. (no need to actually cut anything but check the suction).
> 
> It should be quite a big difference and by adding the canister filter you would get closer to the no filter range of airflow. I checked mine as best i could and there is a difference but not as big of one as I thought, but I have 30 micron bags that I thought were 2 micron. However when I removed the 4" y connector at the DC and checked it, it seamed a little more noticeable.
> 
> My plan is still to switch to a 6" main line and reduce to 4" at each tool port. I also will get a canister filter. I also plan on finding or making something to test the air flow as is with the canister filter and then again with the larger duct. For now I plan on making a dial indicator that will have a 3" plastic ball attached to a string or wire. If anyone has a better idea about how to test it please let me know.


Another Q: When you removed your 4" y connector at the dust collector did you eliminate it from the system or was it only temp for testing? If so how did you connect back to your system?


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> Another Q: When you removed your 4" y connector at the dust collector did you eliminate it from the system or was it only temp for testing? If so how did you connect back to your system?


It was temporary for now but a 6" line hooks in place of the Y connector.


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> That sounds good. If you are going to resize your main I have found an air handling guide pfd to be very helpful. If you would like a copy of it I would be more than happy to share it. It deals with pipe diameter cfm, static pressure guide and calculations if you are trying to make your system more efficient.


Post on this thread I will look at it but it is info for all.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> Post on this thread I will look at it but it is info for all.


Great idea. When I get to a computer I will retype the info from pfd format it is great info.


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## GorillaWood (Dec 30, 2010)

Thanks for all the great info. I will be implementing a lot of it into my design.


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## rrbrown (Feb 15, 2009)

You can just upload the file and others can download it.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> You can just upload the file and others can download it.


Ha after I looked at a link you posted it is the same thing. Air handling systems. Lol


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> A quick check of how much more air flow a canister filter can create over the bag is remove your filters all together and see how much more suction is at the tool port now. (no need to actually cut anything but check the suction).
> 
> It should be quite a big difference and by adding the canister filter you would get closer to the no filter range of airflow. I checked mine as best i could and there is a difference but not as big of one as I thought, but I have 30 micron bags that I thought were 2 micron. However when I removed the 4" y connector at the DC and checked it, it seamed a little more noticeable.
> 
> My plan is still to switch to a 6" main line and reduce to 4" at each tool port. I also will get a canister filter. I also plan on finding or making something to test the air flow as is with the canister filter and then again with the larger duct. For now I plan on making a dial indicator that will have a 3" plastic ball attached to a string or wire. If anyone has a better idea about how to test it please let me know.


rrbrown
I talked to an engineering buddy of mine about measuring airflow, and he recommend that a simple "U-tube Manometer" would be simple and accurate.

A good link is:

http://www.engineeringtoolbox.com/u-tube-manometer-d_611.html


A simple application for use on a dust duct would be a clear tube attached to a board in a u shape, with some water at the bottom (aprox 5' - 6' long may need to be longer, we just don't want to suck out the water just move it). One end opened and the other attached to cap, with a hole to pass the air flow. 

Mark the resting point of the water and up from there in 1" increments.

Turn on your dust collector and see how much the water moves (add a bit of dye to the water for better visability). That is your height.

Use the formula from the the web site above and you have your specific gravity measurement.

You can then move the Manometer to any of your tool ports to measure the static pressure.

I hope this helps
-Gorilla


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## rrbrown (Feb 15, 2009)

GorillaWood said:


> rrbrown
> I talked to an engineering buddy of mine about measuring airflow, and he recommend that a simple "U-tube Manometer" would be simple and accurate.
> 
> A good link is:
> ...


Thank, I'll look into it


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## rrbrown (Feb 15, 2009)

I have some new info to consider. I'm a big fan of the PVC pipe but while at a wood turning meeting at the local Machine sales company (PMC) he brought up an interesting point. Although he agrees static in PVC is not an explosion risk for the small home shop. He did say that the static build up actually works against the air flow slowing it down. I'm not sure I agree totally but It is allot more plausible then the explosion risk theory. Any thoughts?


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## burkhome (Sep 5, 2010)

I hooked up dust collector to table saw and am not satisfied. Hook up on power miter saw and radial arm works well but not table saw hook up... I am thinking about redoing the hood with 2" clear hose and trying to find a clear hood...You can't see what you are doing and the hood doesn't do a good job of picking anything up. 
Table saw is about 5 feet from the cylone which is next to the collector.
Other tools are 12 to 18' from the collector.

Any suggestions.


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## rrbrown (Feb 15, 2009)

burkhome said:


> I hooked up dust collector to table saw and am not satisfied. Hook up on power miter saw and radial arm works well but not table saw hook up... I am thinking about redoing the hood with 2" clear hose and trying to find a clear hood...You can't see what you are doing and the hood doesn't do a good job of picking anything up.
> Table saw is about 5 feet from the cylone which is next to the collector.
> Other tools are 12 to 18' from the collector.
> 
> Any suggestions.


It looks like your running (2) 4" hoses of that single trunk. Unless you have a 6" trunk line from DC through the chip collector and then to the saw, You will have problems with (2) connections on one tool. I have a 4 and a 2 on some tools and it works ok but I'm switching to a 6" trunk line myself. 

What size trunk line is it? what type DC?

What size trunk line between chip collector and DC?

I agree that you need a clear hood but also one with a 2 1/2" hose fitting.


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## woodnthings (Jan 24, 2009)

*I don't think that will work*

You need a shop vac with a localized suction port right at the blade like this made from 2" PVC ..total cost Under $20.00, not including shop vac of course.
The difference is the velocity of the air moved with a shop vac is much greater than a dust collector which moves large volumes of air. This really works. :yes: My dust collector is hooked up under the saw (s) and each has a blast gate, then into 4" drain pipe, then that runs to a short 40" flex hose right to the DC.
It would work a lot better if I sealed off all the holes under the table between the cabinet. Also the slots for the tilt handle....I have the magnetic sign material, I just need to do it. The gaps underneath will require more research....spray foam? too messy. It still does a good job, but it could be better.


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## burkhome (Sep 5, 2010)

rrbrown said:


> It looks like your running (2) 4" hoses of that single trunk. Unless you have a 6" trunk line from DC through the chip collector and then to the saw, You will have problems with (2) connections on one tool. I have a 4 and a 2 on some tools and it works ok but I'm switching to a 6" trunk line myself.
> 
> What size trunk line is it? what type DC?
> 
> ...


 I have a 1 1/2 HP Steel City collector followed by a garbage can separator. Both are connected with 4" flex line and are placed in the next room. A 4" long sweep el brings us through the wall, followed by the blast gate. A 4" PVC Y separates the top pick up from the one under the table.
The collector has 2 4" take offs.


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## burkhome (Sep 5, 2010)

woodnthings said:


> You need a shop vac with a localized suction port right at the blade this this made from PVC ..total cost Under $20.00, not including shop vac of course.
> The difference is the velocity of the air moved with a shop vac is much greater than a dust collector which moves large volumes of air. This really works. :yes: My dust collector is hooked up under the saw (s) and each has a blast gate, then into 4" drain pipe, then that runs to a short 40" flex hose right to the DC.
> It would work a lot better if I sealed off all the holes under the table between the cabinet. Also the slots for the tilt handle....I have the magnetic sign material, I just need to do it. The gaps underneath will require more research....spray foam? too messy. It still does a good job, but it could be better.


 Interesting! Does that little pick up you have really do a satisfactory job? Is it made to swing out of the way if I have something big to cut...IE the top of a box or something similar? I think I have the same shop vac as your red one. It is pushing 30 years old and loud.


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## rrbrown (Feb 15, 2009)

burkhome said:


> I have a 1 1/2 HP Steel City collector followed by a garbage can separator. Both are connected with 4" flex line and are placed in the next room. A 4" long sweep el brings us through the wall, followed by the blast gate. A 4" PVC Y separates the top pick up from the one under the table.
> The collector has 2 4" take offs.


those (2) 4 " take offs are connected to a 6" hole on the DC. With you spitting one 4" line to (2) your starving decreasing the velocity and starving the DC.


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## GorillaWood (Dec 30, 2010)

rrbrown said:


> I have some new info to consider. I'm a big fan of the PVC pipe but while at a wood turning meeting at the local Machine sales company (PMC) he brought up an interesting point. Although he agrees static in PVC is not an explosion risk for the small home shop. He did say that the static build up actually works against the air flow slowing it down. I'm not sure I agree totally but It is allot more plausible then the explosion risk theory. Any thoughts?


After some research, testing, and consulting some engineer and physicist buddies I have concluded static elelectricity does build up, and in massive amounts will slow air flow. Mainly in industrial applications (systems pushing 2500+ cfm) with longer runs of pvc pipe. 

The length combined with the high volume, rate of flow will decrease slightly. But as with dust explosions it is virtually non existant in small home shops.

This is purely my opinion based on my research I've done, testing in my shop explained below. I did my research on the internet with so called fact based sites not other forums (no offence to forums, they just seem like mostly opinions, such as this post), and conversation over topics with friends smarter than me  

In my shop I charged a 10' x 6" pvc pipe conected my dustcollector to one end and hooked up a pressure gauge (harbor freight) at the other. I also used 4" at a 40' length non grounded to maximize the extreams the change was small when grounded vs not. I could not check a run of pipe longer than 40'. I figured that 40' was a sufficient length for the home shop. So I concluded that in a small shop application static electricity slows air flow nominally. But not enough to really make a difference. I will be using pvc in my shop soon. A 6" main reduced to 4" branches to my machines.

I hope this helps

-Gorilla


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## midcent' dave (Dec 20, 2010)

*My DC isn't working worth a crap...*

I recently started setting up my little basement shop room and thought I was going to get a handle on the dust right off. I have my RAS and miter saw sitting on one wall next to each other. I ran 3" PVC behind them (approx. 6ft) with one t for hooking up the miter, then a 90* at the far end for the RAS. The other end Ls down 3ft then hooks to my homemade seperator, then my new 14 gal shop vac provides power. 

I'm guessing the 2" lines coming off the main are just not enough, but I think I should still get better results. The RAS especially is just making huge amounts of dust and I can't catch it. Seems I can only get about 10% no matter how I hook it up. Ive run a single 2.5" line to the dust port ... it then spits all out the back from the blade. I ran the single line behind the saw and closed off the port ... only would suck maybe 40%. I also ran one to the port and one from the miter line to the back ... not much better. 

My vac feels like it could take a finger with suction so I don't know WTH is going on. Do I need to scrap it all and start over? I need to run a vac system for now because we are probably moving I the summer and I don't want to set up a big DC until then. Would using 3 or 4" off lines from the main help. I know I need blast gates if I leave them both hooked up, but I'm ok just swapping back and forth if I need to. Any help or ideas would be soooo appreciated!


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## mdntrdr (Dec 22, 2009)

A shop vac is not designed to move the volume needed for 3 or 4" lines.

You would be better off moving the vac from tool to tool, using smaller lines.

Or seperate vacs for each tool. :smile:


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## rrbrown (Feb 15, 2009)

mdntrdr said:


> A shop vac is not designed to move the volume needed for 3 or 4" lines.
> 
> You would be better off moving the vac from tool to tool, using smaller lines.
> 
> Or seperate vacs for each tool. :smile:



I agree.


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## midcent' dave (Dec 20, 2010)

Scott, if I go back and forth what would be the best way to catch both areas from the RAS? I ran the vac straight to the back but the line is too small to catch everything. If it only goes to the port it catches squat. 

If I got a small wall mount dc or something would that be enough? How much cfm should I need for this small run?

Thanks for the help!


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## mdntrdr (Dec 22, 2009)

They make angled shrouds to go directly behind blade on RAS.

Not sure if your vac will be powerfull enough to suck with one of these tho.

Blade guard ports dont really capture much in my experience.

I wouldn't buy a small DC, you can get a decent 2HP fairly cheap, and then you will have it. :smile:


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## dwendt1978 (Mar 13, 2010)

With all this talk over 6 inch mains, what if your DC has 4 inch ports? Can you use a reducer by the DC to go to 6 inch and then downsize to 4 inch at each machine? Kinda seems like you should just stick to 4 inch if that's all your DC comes with.


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## Rick Mathison (Jun 16, 2010)

dwendt1978 said:


> With all this talk over 6 inch mains, what if your DC has 4 inch ports? Can you use a reducer by the DC to go to 6 inch and then downsize to 4 inch at each machine? Kinda seems like you should just stick to 4 inch if that's all your DC comes with.


If your dust collector has "A" (as in one) 4" port, run 4" mains. If your dust collector has a dual 4" wye, remove the wye and run what ever sized port as your main.

Rick


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