Methods for router table dust collection?

[ian maybury]

Hi all, it seems like a good time for router table questions as there's a few others on the go. As before I'm building an Incra wonder fence, router table and plate and positioner based mobile router table, and seem to be headed for an under table dust collection box. Height adjustment is using a router Raizer, and there's a combined switch and emergency stop unit for control.

Space in the shop is tight, hence the mobile unit. The dust system as many of you know by now is a just installed Pentz based system, so there's lots of puff.

I'd appreciate hearing your views on issues to watch for when configuring this sort of table set up for dust collection. Some that come to mind already are:

1. There's the option to fit a 5in dust connection to under the table (and some recommend this), but there's relatively little by way of open area for the air to be drawn down past the cutter.

Bleed holes are possibly an option, in that it's probably worth getting lots of intake airflow moving in the area of the cutter - but is there a proven solution?

2. The dust connection to the Incra Wonder fence is around 2in dia, which is quite small - and there isn't much opportunity to enlarge it as it's linked to the size of the aluminium extrusion making the fence. Against that it may work pretty well if the tool is well enclosed.

What's the experience in this regard? Hooking it up to a 4in hose (with x4 the cross sectional area) looks risky, it'd drop the air speed in the hose too much for good transportation - but I'd rather not end up messing with a vacuum or the like. It might be more effective to route it back into the under table dust box, and hence back into the larger duct.

3. Mobility is fine, but hanging maybe 8ft of 4in or 5in hose off the back of the router stand isn't all that consistent with this. Especially if hose clips have to be opened and shut every time. Alternatively there's the possibility of leaving the hose connected to the dust system and stashed under the bench in front of the area where the table will be used, and relying on connecting it to the table when needed.

Has anybody got any suggestions for a neat arrangement for this? Preferably one using standard plastic fittings...

4. The under table dust box needs easy access - if only to change the speed setting on the router. (a De Walt DW 625) There's the Incra swing door version, and some straightforward hinged door varieties about.

Are there other designs about that add anything to these?

Thanks,

ian

[Roger Chandler]

Here is my solution - I built a dust collection box for underneath my router table and put a flange on the bottom for the dc hose...............this box along with the dust port on the fence actually gets nearly 100% of the dust and chips.........I have a Delta 50-850 1.5 hp dust collector and it is about 20 feet away........I use 4 inch pvc pipe as my ducts for going across the ceiling of my shop.

Even at that distance my collection at the router table is superb!

IMGP3094.jpgIMGP3095.jpg

[Kent Chasson]

I'll try to get you a photo of mine later today. I (actually, my assistant mostly designed and built it) split the 6" line and ran a 4" to an enclosed box under the table and a height-adjustable one over the table. I added a 4" gate in the bottom of the box. It allows me to adjust the suction and helps avoid eddies where chips can collect. I usually crack it open by about an inch.

It creates a strong suction around the bit and actually helps hold the work down.

It works fantastic most of the time but large bits with no fence will still throw a lot of chips. But the suction is good enough that it still catches the bulk of the fines and a small barricade will catch most of the chips.

[Greg Hines, MD]

I have photos of my router system on here (they do not let you cross post them) but I use a shop vacuum system, with one hose coming off the fence and a second coming off the router (PC-890 with through-the-handle dust collection), and join them with some plumbing fittings to a single point. You should be able to do the same, whether you use a collection box or other way to get chips and dust from the router.

Doc

[Phil Maddox]

I've had the same basic issue with my router table - although I have one of those old Jointech fences. My latest idea is to pull a 4" off of the main DC line - that has to reduce to 2 1/2" at the fence and run a another 4" to the cabinet under the table. I thought it would be better to have the port at the back so it could draw air across router itself - I would make holes in the front to the cabinet to allow make-up air in. My thinking is that this will create a flow of air over the router and grab more of the dust that makes it's way under the table.

I have a 3hp SDG so I have plenty of suction - if you have the CV, surely you do also.

It's all just theory now, haven't built anything, currently I have the jointech attached to a shop vac - does OK.

Good luck.

PJM

[Don Wacker]

I was lazy and just bought a rockler dust bucket and hose fitting. Works pretty good.

Don

[Jim O'Dell]

I was in the middle of making my mobile router table when Bill Huber came up with the idea of making the under table collection box a top draft style instead of pulling all the chips and dust down past the router and out the bottom. It made perfect sense to me as the cooling intake for the motor is at the bottom when the router is in the table. If you pull all the dust down, some is going to be pulled back into the motor for cooling, thus getting the motor clogged up with dust, and/or the motor is going to run hot. I used an HVAC 3X9 to 6" adaptor to mount at the top, and pipe it out to a fitting mounted on the side of the router stand. I can plug my flex hose that is hooked up to the system into it at ease (male to female fitting). I had a 6" hole at the bottom of the box already before I changed the pickup position, so I made a sliding door so I can choke off part of the air input. I may eventually hook up a 2" hose to the cyclone, but right now just plug the shop vac into it. I do have a whole house vacuum that isn't piped in yet that I may hook into it, but that is mounted 20' away on the other side of the shop. All in all it works very well. I also use the Incra fence, and the Woodpecker PRL (version 1). It's a very nice set up. Jim.

edit: Ian, here is the page on my shop rehab thread from years ago that had the RT info: http://www.sawmillcreek.org/showthre...op-Rehab/page5

[Cyrus Brewster 7]

I was in the middle of making my mobile router table when Bill Huber came up with the idea of making the under table collection box a top draft style instead of pulling all the chips and dust down past the router and out the bottom. It made perfect sense to me as the cooling intake for the motor is at the bottom when the router is in the table. If you pull all the dust down, some is going to be pulled back into the motor for cooling, thus getting the motor clogged up with dust, and/or the motor is going to run hot. I used an HVAC 3X9 to 6" adaptor to mount at the top, and pipe it out to a fitting mounted on the side of the router stand. I can plug my flex hose that is hooked up to the system into it at ease (male to female fitting). I had a 6" hole at the bottom of the box already before I changed the pickup position, so I made a sliding door so I can choke off part of the air input. I may eventually hook up a 2" hose to the cyclone, but right now just plug the shop vac into it. I do have a whole house vacuum that isn't piped in yet that I may hook into it, but that is mounted 20' away on the other side of the shop. All in all it works very well. I also use the Incra fence, and the Woodpecker PRL (version 1). It's a very nice set up. Jim.

edit: Ian, here is the page on my shop rehab thread from years ago that had the RT info: http://www.sawmillcreek.org/showthre...op-Rehab/page5

I built a similar set up that Roger has. Although it does an excellent job of DC, I too was sold on Bill Huber's design. As Jim states: "It made perfect sense..." I would hate for my motor to burn up because of dust. At some point I will make one to fit around my PRL (v1).

Jim, if I beat you to making it, I will forward you the design. I am hoping it will not be too tricky to make around the lift - namely too much open space to allow suction at the fence.

[glenn bradley]

1. There's the option to fit a 5in dust connection to under the table (and some recommend this), but there's relatively little by way of open area for the air to be drawn down past the cutter.

Bleed holes are possibly an option, in that it's probably worth getting lots of intake airflow moving in the area of the cutter - but is there a proven solution?

You want to allow an area at least equal to the area of your exit port. The space around the bit varies widely for me and I have throat inserts of varying sizes to keep things safe as the bit diameters change. I just didn't factor the bit opening in at all and consider it to be "just a bit" more than the bleeder holes I have. I started with way too little intake area; I just kept making it larger (on a test door) till I got what I was after. Combined with other openings, it turned out to be almost exactly the area of my exit port which I later read was the way to go . . . doh!

2. The dust connection to the Incra Wonder fence is around 2in dia, which is quite small - and there isn't much opportunity to enlarge it as it's linked to the size of the aluminium extrusion making the fence. Against that it may work pretty well if the tool is well enclosed.

What's the experience in this regard? Hooking it up to a 4in hose (with x4 the cross sectional area) looks risky, it'd drop the air speed in the hose too much for good transportation - but I'd rather not end up messing with a vacuum or the like. It might be more effective to route it back into the under table dust box, and hence back into the larger duct.

My fence port is 2-1/4" and had been pretty satisfactory. It has certainly been good enough that I have not chosen to modify it. Modifying things to suit my needs is not something I hesitate to do so, the fact that i have left this alone speaks well of the performance. I reduce my tablesaw's overarm 4" hose to 3" and then to 2-1/4" which slips into the fence port.

3. Mobility is fine, but hanging maybe 8ft of 4in or 5in hose off the back of the router stand isn't all that consistent with this. Especially if hose clips have to be opened and shut every time. Alternatively there's the possibility of leaving the hose connected to the dust system and stashed under the bench in front of the area where the table will be used, and relying on connecting it to the table when needed.

Has anybody got any suggestions for a neat arrangement for this? Preferably one using standard plastic fittings...

Slip fit DC fittings are widely available. As a matter of fact I think my below the table fitting is a quick connect that I just don't ever remove. It has never slipped off but, my router table is bolted to my tablesaw and neither are mobile.

4. The under table dust box needs easy access - if only to change the speed setting on the router. (a De Walt DW 625) There's the Incra swing door version, and some straightforward hinged door varieties about.

Mine is just a butt hinge door with a magnetic catch. The door has the bleeder holes in it so I wasn't worried about an air tight fit on the door. It just swing shut against a stop block with a magnet in it.

[Jim O'Dell]

I built a similar set up that Roger has. Although it does an excellent job of DC, I too was sold on Bill Huber's design. As Jim states: "It made perfect sense..." I would hate for my motor to burn up because of dust. At some point I will make one to fit around my PRL (v1).

Jim, if I beat you to making it, I will forward you the design. I am hoping it will not be too tricky to make around the lift - namely too much open space to allow suction at the fence.

No, go for it. I'd love to see your design. I'm happy with how mine performs, it's just that some of the dust and chips go to the shop vac instead of the cyclone. Jim.

[Roger Chandler]

To avoid a lot of dust in my router, I take it out of the table frequently and blow the dust out with compressed air........I have had this router for probably 8 or more years...........it runs like new.

The box I built for mine has a little space at the top of it, underneath the table.......maybe 1/8 inch and a little gap at the door as well.........I hold the box to the table bottom with L brackets, and I have found these gaps allow enough vacuum pull that I really get good collection............in my opinion there is so much down draw on the bit, that most of what is cut pulls past the router and down into the 4" pipes..........

The reason I say that is because since putting that box underneath, I have had nowhere near the dust in the router as I did when I first put it underneath the table. The router was used for about 3 years without a box, and since then with one.........boy, what a difference! I think the fact I have the 2.5 inch hose in the fence also makes a lot of the dust collect from the top.

[Matt Meiser]

Kind of hard to see in this photo, but this is what I did for underneath. Makeup air is important IMHO since a lot of time I'm using an insert that is just big enough for the bit. I can adjust the amount of makeup air by moving the flap. I don't need much access to the router since the lift raises the bit above the table. I can reach in the hole to reach the speed selector.

I also have a hose on the fence port. There's a wye on the DC drop there and 2 blast gates. Basically I can tailor my dust collection to the particular task.

[Andy Haney]

Sounds as if you've already got some of it built. If not, I have some pix of mine I could send via email that may be helpful. I also did a lot of studying others when I was building, and determined a method for make-up air "sweeping" the bottom of the space the router hangs in. Send me a PM or email if you're interested.

Andy Haney

[ian maybury]

Thank you for all the input guys, you've really given me a good feel for the available options, and the problems to be solved. Too many to name all, but thanks Jim for the steer to Bill Huber's approach which makes a lot of sense.

I took a look at my De Walt DW 625, and it definitely blows air from the top to the cutter end, with the strongest exhaust from the two slots (about 1 3/4x 1/4in) in the casting to each side of the cutter end.

The point that comes across is that motor cooling and dust issues aside it's possible to collect chips pretty effectively using quite moderate dust system duct sizes and airflows. e.g. 2 1/2in on top, 4in below - or even less. With a vacuum for example.

This makes sense given the relatively small open area in a typical router plate and/or fence.

Sounds like it's a good move to provide for adjusting the suction balance between the collection points though.

It begs the question of how to use/if there is benefit from the sort of high airflows available from the likes of a Pentz/CV system - the big advantage of this sort of system on a saw or planer is that it creates a large enough volume of low pressure air around the cutter (whatever it is) that lots of fine dust that would otherwise escape is pulled in.

This brings into focus the other fairly striking characteristic of a router table: there's really no significant hooding of the sort that you get on a table saw, or a planer. What's more the range of cutter types, their vertical orientation, and the huge range of distances possible from the cutter to the fence makes it tough to design such a thing, and limits the effectiveness of what's there. Yet good dust collection depends on as much dust as possible being deflected towards the pick up point by hoods - the velocity is too high for lots of the dust to be pulled back just by suction.

One option where lots of airflow is available is to open up air bleed holes on e.g. the dust box. The pity perhaps with that is that it places intakes where they are probably not going to do so much to help the above fine dust collection. (or am I missing something?)

An alternative might be to take a lesson from the layout of a a shaper - to arrange a large collection hood of some sort mounted on the fence behind the cutter - and moving with the fence. (all sorts of practical issues pop up) Much of the total air flow would be taken from there. The 2in or whatever port from the fence could also be connected into the duct to this, again subject to finding a practical layout.

Bill H's thinking using a shallow dust box with a close fitting cut out in the floor for the router to poke through makes perfect sense. (not sure if i have it 100%right though)

Are there are issues with chips falling down through the gap between the router and the profiled hole in the box bottom I wonder? (possibly not if the gap is tight enough, and the extraction is always on before cutting)

One option might be to leave an easy empty tray under the router - it could be slightly larger than the dust box, and with sides high enough so that they overlap the dust box leaving only a narrow gap which would also when the extraction was on help stop fine dust escaping. An alternative might be a tough fabric box bottom with an elastic cuff that would fit reasonably well around the body of the router - it'd need figuring out so that it was easy to get the router in and out though.

Either way leaving the router free to pull clean air from outside (the top of the router projects through the cuff, or the hole in the bottom of the box?) was a master stroke. It also make for free access to the speed control on the DW625. The reduced volume inside this 'box' would up the air velocity too, and improve the chances of the space cleaning properly, even on moderate airflows. The airflow generated by the router's cooling fan also assists that generated by the flow towards the extraction duct.

A final thought. There's been mention of chips spewing out when routing a slot or dado in a wide piece - whatever clearance there is between the cutter and the router plate insert ring probably isn't enough to cope. Wonder would it be an option to drill a line of (or several parallel lines of smaller) intake holes in the router plate parallel to the fence, and in the line of the cutter to deal with this?

Glen or possibly Phil - I think one of you mentioned drilling bleed holes, possibly in the router plate. If so how did this work out in respect of interfering/not interfering with the sliding of especially small parts on the router table?

Thank you all again,

ian

[Ole Anderson]

Router table built from a Magazine article years ago. 4" to the lower cabinet with a 2.5" from the lower cabinet (acting as a plenum) to the rear mounted Freud dust collection fitting, which is where 90% of the collection takes place. I have a 3/8" x 4" slot at the bottom of the cabinet to bring in air to sweep material to the outlet.