# Dust Evacuation on Router Table



## Guitarman1 (Oct 2, 2011)

Hi: I'm new here today. This question pertains directly to my router table, but it is more directly tied to issues of dust collection, and I recognize it's come out a bit long in writing, so you might consider paying more attention if you are knowledgeable in regard to both routers and dust collection. 

I have a Grizzly 5 HP, 10-inch table saw with a router table extension. I have a 3 hp Ryobi router mounted to the router table extension. To this point in time I have used it either to route grooves at some distance from the fence or to make cuts using a bearing-guided router bit, so I've gotten away with using the table saw's fence for the work, but I need to optimize the utility of this router table. 

I have several different ideas regarding means to improve the set-up, but one thing I need to make to optimize use of the router table is my focus here. Of course, a lot of the sawdust created by the router falls through the opening in the table and gets strewn all over the room from underneath the table by the spinning router bit, since this is not an enclosed router table system. To deal with that, I plan on making a polycarbonate box to mount to the underside of the table surrounding the router. It will have a hinged door to permit router bit changes and depth adjustment and a 4" dust collector mount on the back side, facing toward my dust collector.

My understanding is that the efficiency of dust collection is largely tied to the available airflow in line with the suction created by the collector. If there is inadequate airflow, the dust promptly falls out of the air in the collector ducts and never gets to the collector. Of course the opening in the router table alone will allow little, if at times any, airflow from above, so I presume I will need to cut some sort of port in the polycarbonate box itself to augment the available airflow to the collector.

Presuming that I am correct in that regard, I have 3 questions. First, what surface area should that port have? Should it be the same surface area as the cross-section of the collector duct or should it be somewhat smaller or larger?

Second, does the shape of the opening matter? I could simply drill a round hole using a hole saw or I could route a series of parallel slots, I imagine. 

Third, if I get the size of the port right, do I need to screen it to keep dust from flying out through it, or should the air flow to the dust collector be great enough to keep dust from being thrown out through that port by the router?

Thanks in advance for any attention and consideration.

Rob


----------



## Cherryville Chuck (Sep 28, 2010)

It's not as complicated as you might think. I just boxed in the area behind and above the bit and drilled a 1 1/4" hole for my shop vac. It gets 95-99% of the dust and chips. I wouldn't enclose the router. The routers I have used in enclosed stands get pretty hot and in an enclosure as small as you are describing it could be worse.
Have a look at the dust chute Lee Valley designed for use on their steel router table http://www.leevalley.com/en/wood/page.aspx?cat=1,43053,43885,42837&p=30041


----------



## Mike (Nov 22, 2004)

Rob, try an experiment: support a piece of 4" hose under your table with the opening as close as possible with out interfering with your routers adjustments. I think you will find this captures most of the dust and chips.(Nothing collects 100%) If you are satisfied with the performance then rig a bracket to support it. When you box in your router it makes adjustments more difficult, and being mounted under a saw table is bad enough. As you learn more about your router's abilities you will be changing your bits, guide bushings and height adjustments more often. Do you really want to have to open and close a door each time?


----------



## the_nite_owl (Oct 19, 2009)

There are products available that wrap around the base of the router to collect the dust coming down through the table. You could probably make something yourself along those lines or buy a pre-made arrangement relatively inexpensively. It is a lot easier than enclosing the router and worrying about the heat generated by the router causing issues. It is also more likely to keep dust from falling down into the router than an enclosure would.

You may eventually want a split fence so that you can use above table dust collection and possibly to use the fence face as a zero clearance insert. You can buy a fence or you can build a saddle for your table saw fence that includes a hollow channel in the middle that you can connect your dust collection to that will pull dust away on top of the table. A Y adaptor will let you connect both top and bottom collection though it is usually a good idea to be able to shut off collection to the top when you are not using the fence in a configuration that can take advantage of collection. That will let you have more suction to the lower port.


----------



## Guitarman1 (Oct 2, 2011)

Cherryville Chuck said:


> It's not as complicated as you might think. I just boxed in the area behind and above the bit and drilled a 1 1/4" hole for my shop vac. It gets 95-99% of the dust and chips. I wouldn't enclose the router. The routers I have used in enclosed stands get pretty hot and in an enclosure as small as you are describing it could be worse./QUOTE]
> 
> Thanks for your response to my question. I do have a tendency to complicate things, but I like to plan ahead and be fairly certain what I'm getting into.
> 
> ...


----------



## Guitarman1 (Oct 2, 2011)

Mike said:


> Rob, try an experiment: support a piece of 4" hose under your table with the opening as close as possible with out interfering with your routers adjustments. I think you will find this captures most of the dust and chips.(Nothing collects 100%) If you are satisfied with the performance then rig a bracket to support it. When you box in your router it makes adjustments more difficult, and being mounted under a saw table is bad enough. As you learn more about your router's abilities you will be changing your bits, guide bushings and height adjustments more often. Do you really want to have to open and close a door each time?


Thanks for the response. I've been going crazy over this because I keep reading about how dangerous sawdust is for the health. On top of that, I have a disability that makes the potential for slipping on sawdust a real problem for me, and it's also not easy for me to have to clean it up after the fact, so I'd really like to collect as much as possible as it comes off the machine.

I can certainly try what you've suggested. I've also gotten a response since I started responding here from The Nite Owl (thanks to you, as well), who suggested consideration of focusing the dust collection more directly around the opening and the rotating bit. The way the router is set up, if I get too much right up around there, it will complicate setting up the tool, but I wonder if it would be worthwhile to make a polycarbonate box shaped to direct the suction from the collector more specifically to the area of the bit from the side, rather than putting the wide open collector hose there. I really don't know whether I'd get better results from having a larger area of coverage with the full hose or from focusing the same suction in a smaller area nearer where the dust arises. I did a quick sketch (only as an elevation view, no scale, and a bunch of cut-and-paste help from Google Images, so it's pretty sad) of what I am thinking, in case it's not obvious, and I will try to attach it. 

Anyway, thanks, again. I can try your way and also try mocking up a box quickly from cardboard and see which seems to work more effectively. At least I'm not getting into as big a project as I initially foresaw.

Rob


----------



## Guitarman1 (Oct 2, 2011)

Hi,
Thanks for your response. I tied it into a response I made to Mike because it all fit together and I didn't want to repeat the same discussion again in a response to you, but you could look there if you'd like to see where the discussion is going.

Rob


----------



## bobj3 (Jan 17, 2006)

Hi Rob

You may also want to look at a sanding box setup, it's just a box with many holes in it that will let all the dust and chips go down the holes and into the bag..

something like below made by Mike
http://www.routerforums.com/attachments/axlmyks-stuff/7314d1187301858-router-sled-sunp0016s.jpg
========


----------



## Cherryville Chuck (Sep 28, 2010)

In any situation where the bit is exposed, the suggestion I offered will work. You are correct about grooving. You would need to follow Bob's suggestion. A hole drilled on either side of your baseplate, centered to the router collet would work if you enclose the router. As pointed out, you will need easy access to the router. If you use a 4" hose you will need 2x 2x 3.14159 square inches (pi r squared) of openings total in your enclosure open at all times for air flow. If you have restricted airflow you will reduce the effectiveness of your vac as well as heating it up. It depends on airflow to keep the motor cool.


----------



## Guitarman1 (Oct 2, 2011)

bobj3 said:


> Hi Rob
> 
> You may also want to look at a sanding box setup, it's just a box with many holes in it that will let all the dust and chips go down the holes and into the bag.
> ========


Hi Bobj3:

Thanks for the input. The problem is that with my setup a collection bag hanging under the router would really (underline that 3 times!) be in the way and from what others have suggested would result in the router overheating. Your recommendation did lead to a consideration that might augment what (I think) I plan to do, though, as I will outline below.

Instead I've decided to create a smaller version of the polycarbonate enclosure I initially planned, based on my thinking-through a recommendation by Nite Owl and thoughts that others have contributed. Instead of enclosing the entire router, it will enclose the upper 6" of it from the back and both sides (looking at it from the end of the table where I adjust the router and change bits) and have attached a 4" collection hose to the side facing the back of the saw table. I will have a hinged door on the front side facing me as I make adjustments, for which I will arrange a quick means of opening and closing that will not make it too inconvenient.

This will reasonably well enclose the business part of the router that expels chips and I suspect maximize the proportion of chips collected. It will leave plenty of exposure for air intake to support the dust evacuation. It will leave the motor of the router completely exposed so there is no risk of overheating and it will not get in the way of height adjustment. The door is intended to help constrain the dust, but I will try to design it in a way that it leaves plenty of room to change the router bits and is easy enough to get out of the way that it is not a major inconvenience to use.

I have thought in response to your recommendation that I could try suspending a broad, shallow sack of some sort well under the router where it would be out of the way of making adjustments and would not enclose the router and expose it to overheating. Then I can see how good a job it does of catching what gets away from the dust collector box. 

I really suspect this will work well. I have attached a couple of quick sketches of a top-view and elevation-view. They are not to any sort of scale but just demonstrate my thinking. Perhaps someone could let me know if something looks like it won't work out or is otherwise a bad idea. Thanks to all for your input.

Rob


----------



## Guitarman1 (Oct 2, 2011)

Cherryville Chuck said:


> In any situation where the bit is exposed, the suggestion I offered will work. You are correct about grooving. You would need to follow Bob's suggestion. A hole drilled on either side of your baseplate, centered to the router collet would work if you enclose the router. As pointed out, you will need easy access to the router. If you use a 4" hose you will need 2x 2x 3.14159 square inches (pi r squared) of openings total in your enclosure open at all times for air flow. If you have restricted airflow you will reduce the effectiveness of your vac as well as heating it up. It depends on airflow to keep the motor cool.


Hi, Cherryville Chuck:

I recognize that your idea will work when you're up against the fence. In fact, I have a fence with dust evacuation built in. My main concern ties to times--frequent it seems in work that I do--when I am not working up against the fence and the fence-associated dust collector is useless or near useless. That is why I wanted to come up with some way to extract dust usefully from below the table.

I'm not in a position where I can be doing any drilling into the baseplate or the inserts because my "baseplate" is the thick cast-iron extension to my tablesaw table and the inserts are also cast metal. I expect what I will do to use the under-the-table dust evacuation is just select an insert that is over-sized relative to the router bit in use, so it will leave adequate room for the dust to be drawn down through the opening. 

Thanks for the calculation. If you review the sketches that I attached to my response to Bobj3 just a few minutes ago, you will see the major air intake will be the cut-out that I make in the bottom plate for the dust evacuation box to fit around the router. I will try to design the cut-outs so that they leave at least 4 pi of extra surface area open around the router when it is all put together. The cutting will be easy, but the calculating and designing may be a mess, given that the router does not have any simple geometric form in cross section to work from! I'll try to come up with some reasonable rough idea and then increase the size a bit.

Getting back to the original issue, though, I am left with one question. I don't know if anyone will have a ready answer for it, and it may just be a matter of getting it all together and trying it out to see what happens. I wonder, though, once I have this put together, if it would usefully augment the dust evacuation tied to the fence to use the dust evacuation under the table in conjunction with it, or if, instead, having suction pulling in 2 relatively opposing directions like this would just decrease the effectiveness relative to using either one alone.

Thanks, again Rob


----------



## Cherryville Chuck (Sep 28, 2010)

At first thought, it seems like you would need to build an enclosure to capture the dust but this may not be the case. The above table methods discussed will capture 95-99% as previously stated and they only sit on one side of the bit. Maybe the same would hold true for beneath the table. This way neither pickup would be working against the other, each would have ample airflow. The Lee Valley magnetic chute would be easy to use this way and would remove quickly to access the arbor for bit changes. You wouldn't have to buy that specific one, you could buy the rare earth magnets from Lee Valley (or a States supplier if you can find one) and epoxy them onto a homemade chute that would maybe be wider so as to better capture from either side of the router. A half-moon shape?
The rare earth magnets have many uses, by the way. I use them for holding my chuck key on my drill press, magnetic catches, a 1/4" one inside a 1/4 by 1/4 drive socket so that I can drive screws with a ratchet, and I even used some to attach a kickboard onto a bathroom cabinet.


----------



## seawolf21 (Jan 19, 2007)

*Dust up*

This is what I adapted to my table.

Gary


----------



## Lee Brubaker (Jan 30, 2006)

I evacuate right at the bit as well as from the rear of the fence....Lee


----------



## MAFoElffen (Jun 8, 2012)

seawolf21 said:


> This is what I adapted to my table.
> Gary


"Sort of" like you Gary. But I did it slightly different. Your way might have been a little easier to do.

I tried at the fence. I still had a build-up on the table and below the plate (on top of my router.

I tried what Mike suggested and wallah. Ah, except that the pocket in my fence would fill up overflowing in a fraction of a second. 

I built a box and ported to the box. In the table, I cut a slit to open it to my fence's pocket. That cured both. When routing off the fence, I just slide the fence (or something) over that hole. 

I was worried about overheating. At least on mine, there seems to be enough fresh airflow drawn down into the box (and around the router) by the vacuum to cool the router... Maybe even cooler than when I didn't have the box and was using just the fence for extraction from above. 

As Mike said, going from down below- My router seems to have less shavings on/in the router. Still signs of, but less. I can live with that.

I think if I did it Gary's way, it would have been easier to do. But cooler? Not sure... I think there might have been less shavings in the router, as all my routers have the intakes on their tops, fan forcing the exhaust out around the bit side.

If I did it again, I am going Lee's route.


----------



## Willway (Aug 16, 2012)

Hi Rob, real nice design work!! I think you would need a hole in the door to give you front to back air flow. This would start the air headed in the right direction. I would use a large hole saw (2in. maybe) and make an adjustable 'butterfly' with a nice little star knob. It can be made out of the piece from your hole saw, or a ping pong paddle shaped piece of polycarb, to control the air flow.


----------

