Router table dust collection

[Hayes Rutherford]

I'm building a cabinet for an older JessEm master lift table. I have the JessEm fence with dust port and want to collect from underneath as well as the fence. I have seen the y fittings that collect from two locations but was wondering why I couldn't run 2-1/2" from the fence to the cabinet and then run 4" to the bottom of the cabinet. my thinking is that it doesn't matter if the 2-1/2" from the fence goes to a y fitting or a fitting on the cabinet since it's the same suction. Any thoughts?

[glenn bradley]

I have seen it done as you describe.

[David Ragan]

Not sure i understand your question, but, on my router table i put a HD bucket up under the suspended router (effectively enclosing it, sealed against underside of the table) and ran a 4" duct from the bottom of bucket and then into a Y, other leg of the Y is DC from the fence-of course, that goes to 6" to main DC.

As a general rule, best to put as large a duct as feasible as close to cutting instrument as you can.

In this case, if I understand correctly, maybe more efficient to collect dust from the bottom with something that can get close (bucket idea). You might loose static pressure with pulling from the entire cabinet.

[Hayes Rutherford]

The router is separately boxed in so in some ways like a dust bucket. I may just give my idea a try. I can always close the proposed 2-1/2" port back up if it doesn't work and use a wye outside of the cabinet.

[George Bokros]

I have the Rockler Dust bucket with the Dust Right Dual Port and it does a pretty good job of dust collection.

Dust Bucket http://www.rockler.com/dust-bucket-d...-router-tables

Dual Port http://www.rockler.com/dust-right-ro...able-dual-port

[Jay Jolliffe]

I did mine as the OP described. I built a box around the motor with a 4" port on the back of the box at the bottom that has a y for the 2 1/2" from the fence. I made a sliding door with 5 1 1/2 holes to let the dust collector draw through the box. I found if I don't run the DC the motor gets really hot & transfers to the mounting plate....Works fine for me....

[Jim Dwight]

I did it this way in my router table setup on the table saw extension table but I thought it heated the router up. The DC pulls air down while the motor's cooling fan is trying to blow it up. So when I built my router table, I put a hose up to the collet area of the router. That way it helps pull air through the router. I think it works better but I didn't do any temperature measurements or anything to prove it. I'm actually not using that right now, however, because I don't have my DC set up. I may try my shop vacuum pulling both ways but I doubt it will move enough air. I use it on the port on the fence and it does fine for edge molding but not for other cuts.

[Hayes Rutherford]

Thanks for all the response. Im hoping to share a 4" hose with a chop saw station. Its at the end of my system but still pretty good cfm. I only have three drops and the first comes off 6", the second off 5" and the last is 4". i don't plan to use the router table a whole lot so switching from the chop saw shouldn't be too inconvenient.

I was hoping to keep things simple and only change the 4" hose, so the 2" would always be connected to the fence and the router enclosure. I guess a 4" x 2" wye fitting could work the same but would always have to stick out the sided of the cabinet.

Hope to follow up with some pics in a week or so.

[ian maybury]

That can be done Hayes, but subject to a few considerations.

Sounds like your hose to the fence is a similar size to my Incra variant below - which means that it needs a fair amount of suction get good collection there.

There can be a bit of a pressure balancing act involved, in that if you run a small dust collector fan with limited suction and CFM capability then (a) the pull through the small duct to the fence may be moderate, and (b) it'll disimprove even more if the chute below has a lot of open area/ends up with quite high CFM flowing through it. i.e. any large opening/intake will hog the airflow, and by dropping the suction may greatly reduce the air flow through the more restrictive branch. It might make sense to use a vacuum on the fence if your dust system fan is very weak.

The latter isn't necessarily a problem with even a half reasonable fan in that if you have inserts for the router plate that are a pretty decent fit around the cutter then there won't be huge volumes of air drawn through it anyway. Big e.g. 15 or 16in fans while the business can without venting create enough suction under the plate to start causing problems with the work being sucked down on to the table and being harder to feed.

Some in this situation (high suction fans) put relief vents in the chute, but that seems a pity - in that it's more or less wasted airflow - although something is needed to create enough airflow in the chute and 160mm duct to give effective clearing and transportation of chips. I went for a third positionable/swivelling connection as in the build and completed table pics below (made by cutting the 'o' ring end off a PVC sewer and drain elbow and setting it in the wall of the chute , gluing a stub to fit a flex hose to the cut end, and then shoving the male end of the elbow in the 'o' ring socket to make the swivel joint. The galvanised steel fittings are the pressed steel spiral ducting type, soldered together to make the small bore branch.

It seemed better than just wasting the CFM via a vent - and it mostly works well in that it can be placed (with a hose mounting clamp) wherever needed to catch chips from e.g. closed slot cuts too far from the fence to make any use of the dust collection there which would otherwise spray chips everywhere.

The key point that made the third connection feasible was running a Pentz/Clear Vue style dust system with their 16in CV Max fan impeller - powerful suction and CFM/airflow. It's easily able to maintain strong suction through the other two ports even with it wide open.

My inclination if running a smaller fan would be to mock up whatever arrangement you have in mind, and to test that it gives decent airflows everywhere you need the before committing to cutting materials. Presuming your fan is matched to your ducting drop/flex hose size one rule of thumb might be that the total open area (intake in fence, intake down through the table and any vent/free use hose like mine might be best to be kept significantly less than the cross section of the duct/flex. This so that the fan gets backed up its curve by the restriction, and there's a decent level of suction/a fairly high intake velocity at the openings..

dust chute connections.jpg hose connections from rear.jpg router table 25-1-12.jpg

[Hayes Rutherford]

Ian, thanks for taking the time to post this. What you've done makes good sense and some light bulbs are lighting for me.

[ian maybury]

No prob. Hayes. Just to repeat - it takes a reasonably powerful dust system as described to run the 'free' collection hose and simultaneously to develop enough suction to run the fairly restrictive fence and through table collection well. Best not done if the fan is smaller - or at least come up with a small plastic blast gate or something (jamming a lightweight kids sponge or similar ball in the open end of the hose when it's not wanted would work too) so that it can if necessary be closed when not in use. I bought one, but in practice never fitted it as it became clear that running with it open all the time was no disadvantage with my dust system.

It works well, but isn't necessarily a 100% always works solution either. Router table dust collection is pretty awkward - in that there are still some cuts well away from the fence for which it's hard to position anything to catch all of the dust.

It's not as built the most airflow efficient layout either - it'd probably be marginally better if the connection from the fence went into the dust chute rather than the outlet elbow. I went that way because it eased the packaging of the whole deal, and it's no problem in this case because there's no shortage of suction and airflow from the dust system.

Since the pic Incra have come out with slotted router plate inserts which i now have - they sometimes (when not blocked by a piece of sheet material) allow a bit more flow down around the cutter.

[Scott DelPorte]

Nice setup Ian. Thanks for sharing.

[William C Rogers]

I did what Ian has done, but nowhere as pro as he did. I think my hose to the fence is 3" and 4" to the box. It works. Ian, very nice and professional looking set up.

[Steven Wayne]

Ian,

Do you have photos of how you extended the Incra table top to support the LS? I have the same setup and am pondering doing something similar..

[ian maybury]

I don't have a photo to hand Steven, but it's nothing very magical.

I didn't want to cut into the Incra table (which has stayed very flat - probably because it is well supported by the steel strips of the trolley underneath) as it would have cut through the edge banding and left it liable to peeling off. (although an inset and glued piece might be stronger) The extension block is just a couple of pieces of birch ply laminated together - sealed and painted when finished using a white car type touch up aerosol. Flat it back after a couple of coats and it finishes up nicely. MDF would do it too.

It's attached using two long 1/2 in hex head lag bolts - which go deep into the table with the longest parallel threaded section as i could find. There's a short length of thread in the last 3/4in or so of the ply block. The logic is that with enough thread area engaged the solid (full thickness) MDF of the Incra table is not much stressed and so doesn't creep/relax and loosen the bolts. Make sure the width is such that they are placed so they don't interfere with the mounting bolts for the Incra locking carriage. (mark it all out before committing anything)

The trick is to get the ply block accurately lined up. Make very sure that the edge face is accurately flat and square - so that when it's butted to the edge of the table it's horizontal/continues the line if the table top and there won't be any tendency for it to rock. It needs to be placed so that the centreline of the ply block is correctly aligned with the positioning of the router plate cut-out as required by Incra.

The holes for the bolts are quite deep. (the length of the block plus the depth of the hole in the tables) I drilled 8mm holes as far as i could reach through the ply block (about 3/4 through it) using brad points under a drill press for squareness/to get accurate centering of the break out at the back (so that the holes the the edge of the table would be on the horizontal centre line) - having first (optional) drilled countersinks for the heads and for double thickness large diameter washers using a forstner. The washers again spread the clamping load on the ply under the heads of the bolts to minimise any tendency to loosen.

Next up was to clamp the ply block hard against the edge of the table, and exactly where required using a flat faced block on top. The locating block was clamped to the router table, and to the ply block. (it holds it accurately horizontal/ensures that the top surface of the ply block is an accurate continuation of the top surface of the Incra table)

Having dug up a long shanked 8mm spade bit the next step was using a power drill to drill through the ply and into the router table edge to the required depth - go deep enough to leave some clear space in front of where the tips of the lag bolts will finish. These holes are to a fair degree self aligning because those already bored in the ply block under the drill press function as guides. The holes were then opened to a close clearance fit on the shanks of the lag bolts - but leaving the last 3/4in or so of the holes in the ply block at 8mm so that the threads could 'dowel' the ply block in location. (the ply block may be left free to drift up and down if the clearance holes are drilled right through)

Finally run in the lag bolts (don't forget the washers) using a socket and the job is done. Just be careful that the lag bolts are not too tight a fit in the holes in the table - if so they could split/de-laminate the MDF. They don't have to be too tight to get a good grip. Lubing the threads with wax helps too.

I chose to use bolts with nyloc nuts to fix down the Incra carriage (on the basis that screws would probably loosen over time), this i seem to remember required opening the holes in the Incra carriage a little and also drilling down through the ply block. Use a backing block clamped underneath and a sharp brad point drill to prevent blow out. Put the thickest large washers you can find underneath to minimise compression of the ply as the bolts are tightened. Should loosening cause any problem it shouldn't be too hard to drill through the mounting plate of the Incra carriage and fit a couple of metal dowels or spring pins to locate it.

Shout if you still need a pic...