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

Thanks Bob,

I am in Beijing working. What takes you to Germany?

Originally Posted by John Samuel

Thanks Bob,

I am in Beijing working. What takes you to Germany?

Science meeting. Even though I am retired I have a further 3 year commitment to continue with this international group.

Originally Posted by John Samuel

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?

Hi John,

It is this whole point about the airstreams fighting each-other and causing turbulence etc that put the idea into my head to NOT have any suction below the table at all. If I make an airtight enclosure around the router, but for the ring where the bit protrudes through the table, then anything that does fall through the ring will settle harmlessly to the bottom of the enclosure and wait to be cleaned out at the end of the day. Dont forget that in my plan the router itself will be "breathing" clean air from outside the enclosure through a snorkel. As you said yourself:

Originally Posted by John Samuel

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

The debris that finds its way into the cabinet is already "collected". It is sitting in the cabinet and can only escape through the ring surrounding the bit. Otherwise, it remains harmless and contained until you open the access door and suck them out with the DC or a shopvac. There is really no need to put it into the dusty itself as it comes off the workpiece. Any effort to do so will create the "airstreams fighting each other" scenario you are trying to avoid.

John, do you know which routing operations result in the larger amounts of dust finishing up in the cabinet are? I am thinking dados/trenches, where the above-table collection is at its worst?

In summary, what I am suggesting is:

- Airtight box surrounding the router with the only air gap being at the ring surrounding the bit to hold anything that drops below the table.

- A snorkel to feed the router clean air from outside the box and create a slight positive pressure inside the box.

- Concentrate the dust collection effort above the table, where the shavings and dust are actually created.

- Open the access door to the box as required to clear whatever falls below the table.

Shavings and invisible dust that are contained in the box are not going to be breathed in nor are they on the workshop floor. Any invisible dust will settle in the box eventually. A small amount may escape through the ring after cutting but if the above-table collection is left running for a short while, as recommended by Bob, then I doubt that any meaningful amount will get into the air we breathe. Similarly, when the access door to the box is opened, to suck out the dust, if you have a 6" DC hose at the ready, it will catch the majority of any invisible dust that may be still circulating in the box before it gets out into the workshop.

Doug

Doug,

Can you help me understand how the pressure inside the cabinet will be positive?

If my 6" line is running over the table, that will pull a lot of air, and some of it will be pulled through the cutter opening. This would tend to make the cabinet pressure negative, but air would then be drawn in through the snorkel (or in my case, through the cabinet vents).

Am I missing something fundamental? It seems likely.

In my wild erratic fancy I actually thought about taking some air from the cyclone outlet to the cabinet (and seal the vents)to put it under positive pressure. In this way significant air would flow up from the cabinet through the cutter opening and be carried into the air stream being created by the cyclone. So, I see the potential benefit of having the cabinet under positive pressure but can't see how it could be made to happen without a lot of mucking around.

What am I missing?

Originally Posted by doug3030

. . . Any invisible dust will settle in the box eventually. . .

The fine dust will go where ever the air flow goes. If the box underneath is closed off, air will not move into it, so relatively little fine dust will enter the box and little will settle there. Although some chips will fall into the box in terms of general dust collection I reckon one might as well seal off the complete underneath of the router but my experience is that routers work better if as much dust as possible is drawn away from them as quickly possible - if the dust is headed for the bottom, then facilitating the rapid removal from the bottom will produce the best result and VV.

Hi John,

I have been out most of the day, going to bed soon, just thought I would try to clear up some of the confusion first.

You posted:

Originally Posted by John Samuel

In my wild erratic fancy I actually thought about taking some air from the cyclone outlet to the cabinet (and seal the vents)to put it under positive pressure. In this way significant air would flow up from the cabinet through the cutter opening and be carried into the air stream being created by the cyclone. So, I see the potential benefit of having the cabinet under positive pressure but can't see how it could be made to happen without a lot of mucking around.

Half a dozen posts back I said:

Originally Posted by doug3030

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.

You said you dont understand the positive pressure. Sorry mate but now I dont understand what you dont understand about it .

To me it seems we both can see an advantage in having the positive pressure in the router enclosure but are going about it in different ways.

The only thing I can think of is that I have not explained the "snorkel" clearly enough and as I re-read the thread and my ideas have evolved, I have to admit that some aspects of the intended snorkel are not as originally posted, so let me elaborate.

Here is how I originally described the snorkel:

Originally Posted by doug3030

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.

4" PVC pipe fits neatly over the end cap of the big triton router, where the air intake is. It is as close to an airtight seal as can be expected. The other end of the pipe is passed through a hole in the bottom of the enclosure. As the router is plunged the pipe will slide up and down through this hole. The router is drawing air from outside the enclosure and will not be affected by any dust that falls below the table into the enclosure

I originally said to leave the hole through the bottom of the enclosure open a bit to allow more air into the enclosure for the dust extraction to take out again. If I have no suction below the table, then it should be made as close to an airtight fit as possible.

The router cooling fan mechanism is sucking clean air from outside the enclosure into the enclosure through the snorkel. This air escapes out into the enclosure through the router body, creating a small amount of positive pressure.

Because it is only a small amount of positive pressure that is what made me think of enhancing it with the compressor, not by blowing compressed air up the snorkel but by having an airhose fitting connected through the side of the enclosure possibly with a means of adjusting the amount of air admitted.

As you said earlier you have thought of sealing all the vents and creating positive pressure by diverting air exhausted through the DC filters. It seems to me we are trying to do the same thing in two different ways.

I hope it is presented more clearly now

Doug

Thanks, Doug.

I missed the bit about the compressor. Must be the CRAFT.

Cheerio!

Originally Posted by John Samuel

Thanks Bob,

I am in Beijing working. What takes you to Germany?

That's why you did not answer the phone!

It gets worse. The phone is on the blink, so even if SWMBO was home, you will not get through.

Telstra tell us it will get fixed ... eventually.

I recall someone who took a different approach to the under table problem. He made a division which fitted fairly tightly around the router between the underneath surface of the table and the upturned base of the router motor thus sealing off the motor itself. He then vented that area with a DE line. The debris dropped through the hole that the bit was in and never entered the cabinet lower area. If that plate was fitted into the cabinet properly and the only way for air to enter the upper chamber was up past the router base then the motor would be cooled with clean air and supply the DE with make up air. That was for any operation like a rebate where the debris was trapped from escaping any other way except down past the router bit.

Above the table is another issue altogether, have you seen a CNC dust shoe?

https://www.google.com.au/search?q=c...w=1676&bih=900


I might be tempted to build a very large version of that so it could be adjusted for height and stopped the debris being flung into the air before the DE can capture it and with the top made of clear acrylic for visibility. Of course it would need to be removable but for flat work it could be effective. I envisage something that covers most of the table high enough to allow hand control of the piece being worked. I put it out there for thought but the practicality of it is dubious I would think but it would work well for dust control.

The back of the fence is another area that should be used so really there are three distinct DE ares that should be used depending on what is being machined and how that is happening.

Hi

I've noted with interest thae various comments made about the Clean Sweep. Rather than reply individually, I'll wait until later in the week when a video will be available that visually and very dramatically refutes virtually all of the negative comments.

Having been involved on the periphry of some of Incra product developments, I know that they wouldn't (couldn't) produce the CleanSweep if all these speculative comments were true. Our order from the first production run is on its way to us and if our current order bank is anything to go by, this is another great Incra product.

Stay tuned for the video.

Regards

Grahame

Originally Posted by Gwhat

Rather than reply individually, I'll wait until later in the week when a video will be available that visually and very dramatically refutes virtually all of the negative comments.

Hi Grahame,

As you know I use a lot of Incra products, and the fact that I noticed the new product on their website shows that I am interested in keeping up with their new products. I do not doubt what you say about their design and testing, and really, I hope it works as well as you say it will.

I am looking forward to seeing the video when you post it. I hope that you understand my skepticism though. Before we digressed to general discussion about below the table dust extraction, everyone who responded and referred to the product seemed to be at least as skeptical as I was. Hopefully there will be some "magic" revealed in the video.

Doug

As promised here's the video, a bit later than expected



Enjoy

Regards

Grahame

Graham thank you for the video.

It still does not address the axcess for changing router bits.

Not everyone has a triton router which comes through the table.

Any thoughts.

Also looks like it will only be of use to those with the incra table insert to use the dust extraction inserts.