Thread: Kreg router fence

I have a similar setup, Kreg Router Table and Fence and a Triton router underneath, I connected a hose from the dust port on the fence to a "Y" piece, I connected another hose to the dust port on the Router into the "Y" piece, and the other opening in the "Y" piece into the dust extractor, it works a treat. If I don't use the fence I just unplug the fence hose from the "Y" piece and just drop in a cap to act as a stopper.

so just the std carp hose. helpful but after you have used 150mm hose & pipe to a 2HP dusty there is no comparison.
and thats what I am trying to work out...
how to enlarge the dust port on the Kreg fence and also getting dust away from the Triton, did I read somewhere that building a box around the Triton and sucking that out is the trick...

If you are worried that the small diameter of the dust extraction at the fence will mean a dramatic loss in extraction power, don't be too worried. By Bernoulli's principle, you still get the same mass flow of air through the system, as through a larger pipe, just with a different balance of pressure and speed of flow. The air doesn't actually get blocked like sand through an hourglass, because air is compressible, unlike sand. True, you'll get higher orifice friction losses, and higher friction losses on the walls of the small pipe until you get an adapter onto it, to step up to 4" or 5" pipe. The bigger pipe will reduce, but not eliminate, the friction losses. But that's why you bought a more powerful dusty, to overcome those losses.

Originally Posted by Gunnaduit

By Bernoulli's principle, you still get the same mass flow of air through the system, as through a larger pipe, just with a different balance of pressure and speed of flow.

Mmmm, I don’t think so. If you add a restriction to a dust extraction system the power drawn by the motor decreases because it’s moving less air (mass flow).

Originally Posted by jack620

Mmmm, I don’t think so. If you add a restriction to a dust extraction system the power drawn by the motor decreases because it’s moving less air (mass flow).

That's the effect of friction. You need to learn about Bernoulli's principle. It's also the basis of flight. Bernoulli's principle - Wikipedia
The point though is, if it was sand you were trying to move, yes, the restriction would indeed fundamentally block particles moving through. Like in the case of an hour glass. But air, being compressible, can adjust from more speed to more static pressure, or vice-versa. So other than friction losses, the same mass will flow through a small orifice as a large one, within a closed system. That's really not in contention. If you still disagree, you need to read up on it.

while I appreciate your comments, I take it you have not read the sticky at top of this section. Myself, Ive used enough various size pipe/hose etc to know 150mm is a power more useful than 100..
Although we do not honour BobL he has done several years both theory & practical research to know what he is talking about and willing to put hours into this area of the forum.

Originally Posted by Gunnaduit

You need to learn about Bernoulli's principle. It's also the basis of flight.

I'm a commercial pilot, but thanks for the lecture. I still say you're wrong.

looking at this fence, Kreg have done a great job in construction, but carp in dust extraction, have a look at thiskreg3.jpg If I stuffed a piece of foam up the spout almost up to either the dust outlet or where the router cutter fits and did that both sides...surely that would improve flow. It would seem to me that dust/air would get mixed up in that void and create merry hell with a decent flow.

the height of Aluminium on exit dust port is 70mm Could the plastic port be removed, enlarge the hole slightly and then using a piece of 100 pipe squeeze it so it finished up elongated but 70mm wide attach it a silicone around any gap. or am I wasting my time.