# Enclosed Compartment vs. Open Compartment



## cchowland (Aug 2, 2011)

Hello everyone,

I am in the design phase of building a multipurpose router table. I am stuck on whether to enclose the router compartment because of the dust factor or go with the open concept because I have read in some posts that if the enclosed is not designed properly it will cause routers to overheat. (have looked at the video link on open concept, I believe on bobJ's {jig design guy} posts.

With that being said, at what cost is that to your lungs (as I have read the Bill Cyclone article about dust - very informative) in using the open concept. Also I have seen alot of designs that have enclosed compartments with vacumn ports in them along with chutes built in and combinations with a port in the fence as well.

I have also seen some designs where a dust port has been built under the table up close to the router. Wouldn't that cause some adjustment problems (ie. bit changes)

I was just wandering what the pro's and con's of the different designs would be. Any input would be helpful and I am not looking to start any Controversy, just want info before I decide which design to go with and also it may help others to see pro's and con's for each design.

At the present moment I have a small table top craftsman table that does have a vacumn port in the fence that I use with my craftsman dry vac. Its works not too bad but I still get alot of dust below the table.

Thanks for your time and consideration in advance:thank_you2:.

Chris.


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## al m (Dec 13, 2012)

Hi Chris
Mine is closed in,in doing so you most likely want a switch on the outside.I have lift so no problems there but with out one you may want a insert to make bit changes easier.I have a 4" dust port below the router and 2" in the fence.Works well,
Al


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## jschaben (Jun 21, 2009)

Hi Chris - You will get the lions share of dust from the fence collector. I just use a shop vac but it's split between the fence and the box. I ended up removing the door of the box and don't notice a big difference in dust on the floor in front of the table.


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## BrianS (Nov 7, 2004)

Chris, you will never get all the dust, no matter what you use for collection. Wear a good mask as well as using dust collection. As John said, the fence port will get most of the dust. I probably have the same, or very similar, table and the fence does a good job. I also closed my table in on 4 sides, but have since left 1 side open for air circulation.


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## denniswoody (Dec 11, 2011)

I have a fence collector hooked up to a shop vac and a closed box below that has a 4 inch hose to a 1 HP dust collector. With both running I get very little free dust. The 4 inch hose generates so much air flow it cools the router.


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## Cherryville Chuck (Sep 28, 2010)

1 more for the fence collector. All of the dust you make will happen from level with the table to possibly 2+ inches above the table if you are running a molding bit. So why would you put your dust collection under the table? Also, the fan on the router is designed to take in air at the top and exhaust it at the bottom near the bit. If you are trying to suck air through that area you are working against it, probably the biggest reason the router runs hot. Sucking air from above the table probably helps it run cooler since the vac is sucking in the same direction that fan is blowing. 

So, if enclosing the router doesn't help with dust control and causes the router to run hotter , then why do it?


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## al m (Dec 13, 2012)

I cannot say how much dust is pulled under the table,but there is definately a percentage as witnesed by what clings in the corner of the enclosure.I am sure different operations pull dust in different ways.As a example,when cutting dovetails the fence is so far from the cutting very little,if none, is pulled by the fence port while the port below the table pulls the lions share.When doing a edge profile close to the fence the fence port will of course pull the bulk of the chips.I can say for a fact since I have set up this system my shop is much cleaner.I am using a 1 hp dc with a super dust deputy,pulling through a 4" hose with a y too the 2".It is relatively new to me so I cannot atest to the long term affects to the router but I know I can replace a router much easier than a lung.
I think it is worth it


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## JOAT (Apr 9, 2010)

cchowland said:


> With that being said, at what cost is that to your lungs (as I have read the Bill Cyclone article about dust - very informative) in using the open concept.


Dust mask. I would advise a good dustmask, and not one of those disposable things like the dentist uses, but a real dust mask, with replaceable filters, whether you have dust collection or not.


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## al m (Dec 13, 2012)

I do agree with a quality dust mask,but as a tradesman in industry was always taught to control the hazard at the source first,then personal protection next.I am not saying do not use the mask but rather it should compliment a good extraction system.What we do not know is what Chris is using for a dust collector,if just a shop vac I concure the fence is most likely the way to go.If you have a dc system,Chris,I would recommend closing in the router and collecting from both locations.Just one opinion,of coarse


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## jschaben (Jun 21, 2009)

I think the absolute best way to handle a router table is combination of fence pickup and pickup from the collet area rather than from a box around the router. As Chuck pointed out, pickup from around the router body is pulling against the designed router airflow. My first portable table use a Freud 1700 and I kept the factory dust collection shroud on the base and picked up from there as well as the fence. The result was very good with very little dust showing up on the table beneath the router. 
The downside of this method was that the factory dust shroud really didn't allow use of very large bits so I left it off my floor standing table and just pick up from the open box which does collect a significant amount of dirt. 
While the fence + collet pickup works pretty well, there is still the issue of doing dado's/grooves where you are routing essentially a closed channel and the dirt has no way out except directly toward the outfeed end of the table. In those cases virtually all the dirt goes that way. The only thing I've seen that might be effective for that is the Oak Park vacuum plate.


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## al m (Dec 13, 2012)

This thread certainly has me wondering if there is any real potential of my router overheating.I also do not want to hijack the thread but it does seem relevant.My router is a pc 7518.I just fired it up for a moment without the dust collector running.It seems that airflow is in the same direction as the dustcollector moves the air.Is this true of all routers,and if so woult the dustcollector not enhance cooling in that case?


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## OPG3 (Jan 9, 2011)

I use an open frame style router table - this allows for the best possible fan cooling and in my case makes for best ease of making adjustments. I often wear a mask when creating dust. My dust collection system is piece-meal, but overall does a good job.
I also utilize a high-capacity HEPA filter when the shop is idle. My dad used to say, "If you create a problem to solve another problem, then all you're doing is wasting money."
Otis Guillebeau from Auburn, Georgia


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## denniswoody (Dec 11, 2011)

I have to disagree with those against under table dust collection. In my experience there is a lot of dust falling down that the the fence collector won't catch. If your box is reasonably large there is little chance of the router overheating. Also worth considering is how long you actually run your router in a table application. Again in my experience as a hobby woodworker I only run it for short periods of continuous use.


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## Dmeadows (Jun 28, 2011)

denniswoody said:


> I have to disagree with those against under table dust collection. In my experience there is a lot of dust falling down that the the fence collector won't catch. If your box is reasonably large there is little chance of the router overheating. Also worth considering is how long you actually run your router in a table application. Again in my experience as a hobby woodworker I only run it for short periods of continuous use.


I agree, Dennis, I rarely run my router long enough for a reasonable sized space to be a problem. Also air flow must be sufficient to keep from starving the dust collector system anyway. If you to seal an enclosure and hook up a dust collector(vacuum source) you won't remove a lot of dust anyway, you'll just pull a vacuum on the enclosure! 

There must be sufficient air flow for the dust collector to work properly! If you provide proper air volume for the DC, and it flows around the router. heating should not be that big an issue. A bigger heating issue comes from allowing the dust to accumulate in the router housing! The router most likely should be removed from the table and cleaned periodically. The less efficient the dust collection the more frequently this is needed!


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## gwizz (Mar 3, 2012)

Well Chris you asked for it and that’s what you get here 9 or 10 responses with 12 or 13 perspectives.

Personally I agree you get chips and debris both top and bottom, but I’ve yet to see a pickup system that captures it all, so make it easy to clean up as you go. I had pickup both top and bottom but removed the hose and pickup from the bottom. My table was always open on the front so I opened it up on the side as well which gives me easy access ( my router is not dedicated to the table ) as well it makes it easy to sweep out and not pile up around the router.


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## greenacres2 (Dec 23, 2011)

On Saturday, i routed a 5/32" groove 5/16" deep on about 120" of oak & cherry. Turned on the DC for each pass (remote switch). When i finished, i opened the cabinet and learned that you get zero dust collection when you fail to attach the hose to the cabinet!!

Your mileage may vary, but probably not!!


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## Dmeadows (Jun 28, 2011)

gwizz said:


> Well Chris you asked for it and that’s what you get here 9 or 10 responses with 12 or 13 perspectives.
> 
> Personally I agree you get chips and debris both top and bottom, but I’ve yet to see a pickup system that captures it all, so make it easy to clean up as you go. I had pickup both top and bottom but removed the hose and pickup from the bottom. My table was always open on the front so I opened it up on the side as well which gives me easy access ( my router is not dedicated to the table ) as well it makes it easy to sweep out and not pile up around the router.


Here is a 14th perspective, Richard. When you are cutting dadoes, you get _zero_ DC from a fence mounted hose! Just sayin... Of course the dado itself often does a fair job!:yes4:


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## Cherryville Chuck (Sep 28, 2010)

Duane, you're correct in that dadoes are a problem with dust collection on a table. It is, however, possible to deal with it if you plan ahead of time by putting vacuum ports in the table in-line with the bit opening. 

A router sucks air from the top end and exhausts it at the collet. If you are using an insert that is close to the same size as your bit, which is what you should be doing, then there is very little air flow through the opening. The router is trying to push air up through the opening and if you have a vac system under the table, then it is trying to suck air down through the opening. Logically, this doesn't make sense. 

There is no disputing the fact that any routing operation happens at table level or above it. So if the the router is trying to push air from below the table up past the collet and all the dust making is above the table, then why would you put dust collection below the table working against the the router's airflow unless the below table dust collection is at collet level which would enhance the router's cooling capacity AND also above the table at bit level which would enhance dust collection capacity?

The truth is that because of the routers spin, most dust particles would be thrown outward, not down or up. Only random particles, bouncing off of other particles at extreme angles would escape a good vac system. If you have a router blowing air up from underneath, and a good pickup above table there shouldn't be much left over.


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## Dmeadows (Jun 28, 2011)

Cherryville Chuck said:


> Duane, you're correct in that dadoes are a problem with dust collection on a table. It is, however, possible to deal with it if you plan ahead of time by putting vacuum ports in the table in-line with the bit opening.
> 
> A router sucks air from the top end and exhausts it at the collet. If you are using an insert that is close to the same size as your bit, which is what you should be doing, then there is very little air flow through the opening.Exactly! If not thru the opening,Uh where is it going? It is bouncing of the routerplate/table! The router is trying to push air up through the opening and if you have a vac system under the table, then it is trying to suck air down through the opening.This is why you need some venting.. it cannot pull enough air thru the bit opening! Logically, this doesn't make sense. Maybe becaused it not based on reality! There is little positive pressure to force air thru the small opening. The router cooling fan just recirculates air. Positive pressure would result if the router intake is from outside the enclosure, but I've never seen anyone do that!
> 
> ...


Sounds good, but I have never seen it work that way. I like the dust collection accessories that either come with or are available for many newer routers. At this time I don't have one of those in my table, and trust me, with fence based DC I get_ very little_ dust on top of the table, but still a _lot_ underneath. May be illogical, but that is the way it works for me! 

I think the router airflow does indeed have an effect, but it is probably more to help scatter the dust and chips, than to force it back up the opening!


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## Cherryville Chuck (Sep 28, 2010)

Duane I'm not getting that much under my table. BJ posted a link a while back on this same topic that was a Youtube video of a guy who is selling router tables. He said that he gets very little under the table also and his design was open front and rear with drawers on the sides. He also advocated against putting the DC under the table in a box. I've used one at a mantel factory that I worked at once that was totally enclosed and the router got very hot and the dust collection was lousy.

I haven't had a chance to use a router with the DC attachment on the bottom. I suspect that they were mostly meant for handheld routing where there is no DC otherwise. How well they they would work on a table I don't know. One thing I do know is that I am working over the table and I want that side to be clean and free from dust. The dust below the table may be a nuisance but it is nowhere near the health hazard as the dust above.


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## bobj3 (Jan 17, 2006)

Deluxe Router Table..Improved - YouTube

==


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## cchowland (Aug 2, 2011)

Thank You for all the input so far. 

Even with the different perspectives it can only help people gain more knowledge to come up with better designs.

At this point I am leaning towards the open concept, but I am still going to do a little more research, so keep the input coming as it can only help all of us.

Thanks again, Chris:happy:


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## cchowland (Aug 2, 2011)

Thanks Bj,

Have seen the linked video you are referring to and mentioned it in my first post. Not sure how to do the link thing yet or would have used it 

Chris


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## Bikeworks (Oct 24, 2012)

One thing I have learned with an enclosed router is "Make-up Air" is very important. You must provide some cross ventilation from some other point in the enclosure besides the bit hole in the table insert that your router hangs from. Otherwise, you are pulling make-up air from the bit hole down into the router enclosure. I have two one inch holes in the access doorway in my enclosure that seem to provide just enough make-up air to allow chips and dust to exit the bit area through the fence collection. I believe it also helps supply cooling air to the router motor. Before I provided that make-up air a good portion of the dust/chips would try to exit straight down into the top (bottom) of the router. I have found that this set up is a good balance for almost every bit type I use whether they are close to the fence (which I always have in back of my cut over the port that supplys the vacuum) or not.


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## Cherryville Chuck (Sep 28, 2010)

Bikeworks said:


> One thing I have learned with an enclosed router is "Make-up Air" is very important. You must provide some cross ventilation from some other point in the enclosure besides the bit hole in the table insert that your router hangs from. Otherwise, you are pulling make-up air from the bit hole down into the router enclosure. I have two one inch holes in the access doorway in my enclosure that seem to provide just enough make-up air to allow chips and dust to exit the bit area through the fence collection. I believe it also helps supply cooling air to the router motor. Before I provided that make-up air a good portion of the dust/chips would try to exit straight down into the top (bottom) of the router. I have found that this set up is a good balance for almost every bit type I use whether they are close to the fence (which I always have in back of my cut over the port that supplys the vacuum) or not.


Tim, in some operations you might catch most of the chips and dust by sucking downward. But what about tall molding bits, vertical raised panel bits, or bullnose bits? I would point a few things out to you. Two one inch holes is only about 1.6 square inches of area. How big is your vac hose cross sectional area? It should be at least as big as that and I wouldn't count too much of the insert hole as it can be covered up by more than 50% between your work and the bit.

The router is trying to push air up through the hole so it seems illogical to me to try to draw air back down through the hole. While what you have done may have helped, I can't see it being an improvement over moving air in the same direction.

While the mess below the table is a nuisance, i don't think it is that dangerous. The dust above the table is dangerous to your health so I am most concerned with that. My dust collector is integrated in my fence and keeps my table clean which makes me believe that it is also keeping the air I breathe fairly clean too.


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## Dmeadows (Jun 28, 2011)

I agree that two 1" diameter holes will not allow enough airflow. I don't agree that much air is being pushed up around the router bit. As you state the hole is usually 50% blocked(more or less). Also if the hole is sized right for the router bit, there just isn't that much space around the bit. Most of the airflow from the router fan is just going to bounce of the router plate!

I don't think _chips_ above or below the table are that dangerous. The fine dust, however, is, even if it is coming from below the tabletop, especially if the router area is not enclosed. Airborne fine dust, is airborne fine dust, period! Not only that, but as you point out, the forced air from the router tends to blow it around!

A properly enclosed area with proper ventilation should collect most of that, no? May miss some chips, true. With properly balanced airflow, it should also do an adequate job of cooling the router. If the DC starves for air, that will cause overheating and very poor dust collection.

Convenience changing bits and such? That's another issue, but a hinged door shouldn't be that much of a problem for that either.

Remember, it is the fine dust that is the larger health issue, not the larger wood chips!

Just my opinion, but show me how I am wrong!


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## Cherryville Chuck (Sep 28, 2010)

Dmeadows said:


> I agree that two 1" diameter holes will not allow enough airflow. I don't agree that much air is being pushed up around the router bit. As you state the hole is usually 50% blocked(more or less). Also if the hole is sized right for the router bit, there just isn't that much space around the bit. Most of the airflow from the router fan is just going to bounce of the router plate!
> 
> And yet you expect to get good dust collection from this situation.
> 
> ...


Did I manage this time? You asked for a scientific explanation and hopefully I gave it to you? By the way, the last 1 1/2 years I spent at the University of Alabama was as a physics major so I feel I have a pretty good comprehension of the principles involved here. If you can prove me wrong, I'll readily accept that but what I know about physics doesn't point to that conclusion.


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## Dmeadows (Jun 28, 2011)

Cherryville Chuck said:


> Did I manage this time? You asked for a scientific explanation and hopefully I gave it to you? By the way, the last 1 1/2 years I spent at the University of Alabama was as a physics major so I feel I have a pretty good comprehension of the principles involved here. If you can prove me wrong, I'll readily accept that but what I know about physics doesn't point to that conclusion.


1. Yes, I expect better dust collection with than without it. Agreed, no dust collection is perfect. And I never, ever, suggested not also having fence based DC as well!

2. I agree with the mass/velocity issues and that _most_ but not all of the fine dust will get caught by the top DC... unless cutting dadoes, or some other closed cut. Then the top DC from the top is _near zero_. In spite of this I still get a coating of fine dust below the router without DC even on edge cuts. With an open cabinet, where it goes depends on many things like like convection(routers and routing do generate heat), HVAC air flow, etc. I still contend the larger % of the router airflow forces much of it out of the table when not enclosed.

3. I notice you don't contest my claim about overheating!:yes2:

4. Convenience is a personal preference. Some like having bit and accessory storage in the table. Some change bits from above the table, some remove the router and plate... Really no right or wrong answer to this one!

5. Most surely glad we agree on the fine dust issue!

So, my conclusion? Top and bottom dust collection is my choice. I think it is a case of more is better. 

Other than that, guess we'll just have to agree to disagree, Charles. But it is an interesting and needed discussion!


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## Bikeworks (Oct 24, 2012)

Cherryville Chuck said:


> The router is trying to push air up through the hole so it seems illogical to me to try to draw air back down through the hole. While what you have done may have helped, I can't see it being an improvement over moving air in the same direction.


Um, Chuck, you are right, that would be "illogical". I'm not sure where you got the impression I was trying to pull air down toward the router. I said that that was a problem and I reduced the problem with the make-up air.

Make-up air solves some of the problems that you mention (overheating, air flow direction). In a previous post you mentioned you have had no experience with enclosed routers (other than what sounds like a poorly designed system for making mantels). Mine works great. Air quality is the best in my shop ever. 

4" port from a 350 cfm DC attached to the enclosure. 2.5" port in the table top feeding fence collection. Two 1" holes in the door for the enclosure and a non air tight enclosure (and wasn't designed to be airtight). I have little problems with airborn dust. I also run a homemade dust filter which catches most of the rest of the airborne dust.

Tim


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## Dmeadows (Jun 28, 2011)

Bikeworks said:


> Um, Chuck, you are right, that would be "illogical". I'm not sure where you got the impression I was trying to pull air down toward the router. I said that that was a problem and I reduced the problem with the make-up air.
> 
> Make-up air solves some of the problems that you mention (overheating, air flow direction). In a previous post you mentioned you have had no experience with enclosed routers (other than what sounds like a poorly designed system for making mantels). Mine works great. Air quality is the best in my shop ever.
> 
> ...


Tim, overall it sounds to me like you have a very good solution!


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## Cherryville Chuck (Sep 28, 2010)

Dmeadows said:


> 1. Yes, I expect better dust collection with than without it. Agreed, no dust collection is perfect. And I never, ever, suggested not also having fence based DC as well!
> 
> 2. I agree with the mass/velocity issues and that _most_ but not all of the fine dust will get caught by the top DC... unless cutting dadoes, or some other closed cut. Then the top DC from the top is _near zero_. In spite of this I still get a coating of fine dust below the router without DC even on edge cuts. With an open cabinet, where it goes depends on many things like like convection(routers and routing do generate heat), HVAC air flow, etc. I still contend the larger % of the router airflow forces much of it out of the table when not enclosed.
> 
> ...


I have considered adding an extra dust pickup against the bottom side of the table but my concept is a half moon shaped pickup that would fit around the router base. This would capture almost all the debris going downward and would work with the router's own airflow. It would also eliminate the need for an enclosure. I am considering a cabinet for my next build but it would be open on the front and back like the one in the link BJ gave.


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## Cherryville Chuck (Sep 28, 2010)

Bikeworks said:


> Um, Chuck, you are right, that would be "illogical". I'm not sure where you got the impression I was trying to pull air down toward the router. I said that that was a problem and I reduced the problem with the make-up air.
> 
> Make-up air solves some of the problems that you mention (overheating, air flow direction). In a previous post you mentioned you have had no experience with enclosed routers (other than what sounds like a poorly designed system for making mantels). Mine works great. Air quality is the best in my shop ever.
> 
> ...


The cabinet I mentioned was fairly large, basically just a big box. It was used rarely, we mostly used the routers handheld. The one time I remember using that cabinet mounted one was with a big Makita with a small profile bit in it so it wasn't working very hard. It got so hot I could feel it through the cabinet.

My point still is if you can get the same dust collection without putting the router in a cabinet, then why bother?


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