Thread: A new commercial product for enhancing dust extraction on a router table

Doug,

For many of us this gear will be a moot point, because it only fits an Incra Router plate. It wont fit on my Jet spindle moulder, nor would it have fitted on my old router table.

It might be OK when routing slots etc, but I fail to see how it could be effective when routing edges of cabinet tops, shaping cabriole legs and etc. As you suggested, surely it can't pull enough air through those slots to be effective in those applications.

I'll be interested to hear what BobL thinks, but I can't say I'm overly impressed at this stage.

Seems like a pretty small box. Could there be issues with the router over-heating?

As indicated I would be concerned about the router overheating,

You also have all the dust getting drawn over under and in the router.

Just noticed graham has them in his latest newsletter.

Clean Sweep Downdraft

Would be interested in seeing the access for changing bits as well

I sincerely doubt the ability of that system to collect the majority of invisible dust at source.
The choke points for that system are the tiny holes that will simply not allow enough air in at the top - I reckon they will be lucky to pull 100 cfm with thta setup

Originally Posted by Jim Carroll

As indicated I would be concerned about the router overheating,

I wouldn't worry about this even a hundred CFM of air will be enough to cool the motor

You also have all the dust getting drawn over under and in the router.

I agree that extraction from underneath is not ideal as it surrounds the motor with dust.

When I do my router DC I will make a box that surrounds the router that extracts air and sawdust from one side with a large vent allowing fresh air in on the opposite side. The saw dust will thus be entrained by the low pressure generated by fresh air flowing across the motor. Most of the dust will then be drawn out from the side of the router.

Ideally the collection port would be a 6" with a 4" port on the top.

Originally Posted by Jim Carroll

Would be interested in seeing the access for changing bits as well

That had occurred to me as well Jim, but since I use a Triton router (above-table bit changes) in the table that was one thing that I was not overly concerned about.

Doug

I am a doubter also, sorry Graham but the idea does not stack up. I had the idea of a gridded top plate so that the extraction does not suffer from not enough air though I doubt it could be made stiff enough and it may not work anyway.

Originally Posted by BobL

When I do my router DC I will make a box that surrounds the router that extracts air and sawdust from one side with a large vent allowing fresh air in on the opposite side. The saw dust will thus be entrained by the low pressure generated by fresh air flowing across the motor. Most of the dust will then be drawn out from the side of the router.

Ideally the collection port would be a 6" with a 4" port on the top.

I have an Incra router table and stand but building in under it for dust collection and storage is still a work in progress for me too, Bob. The table works so I use it but I still need to get the dust extraction optimized.

I like your idea of a cross-flow to ensure clean air to the router motor but I have another plan for mine.

The end-cap which houses the air intake on the big Triton router fits neatly inside a length of 4" pvc pipe. You just need to cut out a notch for the speed adjustment dial.

The plan is to make a box surrounding the router and mount a DC port either low in the side or in the bottom.

A piece of PVC pipe will extend from the end of the router out through the bottom of the box to act as a snorkel. The snorkel will extend and retract through the hole as the router is plunged. A little bit of clearance around the snorkel will allow a bit more air into the box so that will not be an issue.

I know that not all routers will fit so neatly into a convenient size of pipe but a modification of this plan should be possible for most routers.

With my 2hp 6" DC I can run 2 x 4" ports at the machine so for me it will be 4" above and below. I cannot see much point in running 6" under the table anyway because of the lack of meaningful intakes that can be opened up to allow sufficient airflow to make it worthwhile.

The above was my plan before I saw the Incra Cleansweep, and it has not changed.

Doug

The pic

Although this product is not suitable for my Jet machine, it has got me thinking about dust extraction on that beast.

Currently, I have a couple of 150 mm ports. One for when using a fence (cabinet tops, raised panels etc with a fence - see first pic), and one for freehand work or work with sleds (cabriole legs etc - see second pic). The bulk of my work is the former.
IMAG0102.jpgIMAG0127.jpg

But I have no dust collection from inside the cabinet itself. Not usually a big deal, because for most jobs not a lot of dust reports there ... but sometimes some does. So, thinking of running a line to the cabinet. Checked Bill Pentz's site. The drawing he provides shows a 3.5" line to the fence and a 5" line to the cabinet.

However, because most of my work needs the bulk of the dust and chips to be collected from over the table, thought I'd reverse that and run a 90 mm line to the side of the cabinet. Also, when doing freehand/sled work, I really need that high airflow over the table, and I can't imagine a smaller line coping.

Before I get too carried away, does all this sound as if I am on the right track?

Originally Posted by John Samuel

However, because most of my work needs the bulk of the dust and chips to be collected from over the table, thought I'd reverse that and run a 90 mm line to the side of the cabinet. Also, when doing freehand/sled work, I really need that high airflow over the table, and I can't imagine a smaller line coping.

Before I get too carried away, does all this sound as if I am on the right track?

John, I think of it this way:

All of the cutting done on a router table is done above the table, That is the whole point of mounting the router in a table in the first place. Therefore ALL visible and invisible dust is created above the table. That is where the majority of the collection effort should be.

However some dust will fall down through the ring. This should not bother you except for the fact that it might bother your router and its source of clean air to suck through the body to keep the motor cool. That's why I was talking about using a length of pipe as a snorkel to ensure a clean air supply to my router. You may have a different way of doing it with a shaper.

In either case if more invisible dust can be captured below the table that would be a good thing. but in any case, I cannot see any benefit in sacrificing dust extraction capacity above the table to increase capacity below the table.

I think you are thinking on the same track John. In fact I am considering not having any extraction at all below the table, just enclosing it so that any dust that falls below remains trapped and harmless, just waiting to be sucked out later. The router could breathe clean air through the snorkel. The air that the router is sucking into the enclosure below the table would create a high pressure in the box surrounding it, which would escape through the ring.

This escaping air would cause less material to fall down into the enclosed space and less invisible dust to enter and allow them both to be dealt with efficiently above the table.

If I do this I can concentrate the full capacity of my 2hp 6" system where it will do most good and leave the small amount below the table to be sucked out either by dropping a DE or Vac hose in later when work if finished and I am running the Dc anyway to scrub the air.

However, when routing a trench/dado, and you cant collect from anywhere else than the end of the table where the trench comes out or from under the table through a hole, it makes me rethink the above. There are no "one size fits all" solutions.

I am thinking seriously that I go with the enclosed box, no suction, snorkel option for everything else and for dado cuts making /modifying a ring to allow a VC nozzle to clear the waste from the dado just past the cutter, only fitted when doing that type of work.

Opinions please,

Doug

EDIT: I was going to mention upcut spiral bits as well since when the router is mounted in a table the efectively become downcut bits and would increase the amount of waste going below the table. I think as long as the router is still getting fresh air through the snorkel all would be good.

Originally Posted by doug3030

. . . .However, when routing a trench/dado, and you cant collect from anywhere else than the end of the table where the trench comes out or from under the table through a hole, it makes me rethink the above. There are no "one size fits all" solutions.

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EDIT: I was going to mention upcut spiral bits as well since when the router is mounted in a table the efectively become downcut bits and would increase the amount of waste going below the table. I think as long as the router is still getting fresh air through the snorkel all would be good.

Yep there needs to be some below table collection. Even if it looks like the cutting is on top, the direction and shape of the bit can sometimes redirect sawdust below teh table.

Originally Posted by BobL

Yep there needs to be some below table collection. Even if it looks like the cutting is on top, the direction and shape of the bit can sometimes redirect sawdust below teh table.

Bob, I am not sure where you are coming from here. Can you clarify why you say there needs to be some collection below the table? I was proposing that for all operations where the router bit was working on the outside edge of the workpiece that any shavings or dust that fell below the table through the ring would be contained harmlessly in the airtight box below the table until they were later sucked out by the shopvac or the DC.

Have you considered that part of what I am putting forward also involves the snorkel which is providing clean air to the router which is producing a high pressure area in that enclosed box. This high pressure is forcing the air out through the ring on the table allowing the dust to be collected by the above table dust extraction methods.

I would have thought that having a high pressure area below the table was a very good thing and was even thinking of enhancing it with the compressor to stop dust falling in there either in addition to or instead of the snorkel.

Can you please review what I wrote before and in this post and elaborate on your opinion as to why you think this is not a good idea?

Has anyone considered blow rather than suck below the table before?

Doug

Sorry Doug I did not read your post carefully enough.
Am doing this from a bar in Frankfurt and the local beer must be doing my head in!

RE; Practicalities of using a compressor to pressurise a box underneath the Router bit.
Given the relatively large area of the opening around a router bit a compressor will vent it's total stored air in about 2 seconds through such an opening and after that it will generate much constant flow. Unless you are talking 20kW compressors a small compressors will only generate a few CFM so it wont't be able to generate much of a pressure gradient pressure tour. While it should be able to keep some of the fine dust out, it won't have the 4000 fpm to prevent settling of larger chips in a vertical direction so the underneath will fill with chips anyway. Besides I don't like using small compressors this way i.e. in FAD (free air delivery) mode for more than a few minutes which would stymie some router operations.

OK ...

For most applications, very little dust gets into my cabinet, but occasionally an appreciable amount does.

I think I will go ahead and fit a 90 mm line to the cabinet and test the performance. I am lucky to have pretty good air flow, so I should be OK.

My thinking is that the cabinet port will be at least a foot or so below the table, and that by the time the dust gets there its velocity will be low, so I'm thinking a 90 mm line will pull enough air to clear this dust.

What is exercising my mind a little is that I might create turbulence around the cutter where the two air streams converge, one from over the table and one from under the table. Put another way, around the cutter the two air streams might fight each other. Any thoughts on this?